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Backport #2693: Fix Workflow loader source map warnings#2926

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Merged
NathanColosimo merged 3 commits into from
Jul 14, 2026
Merged

Backport #2693: Fix Workflow loader source map warnings #2926

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2a14260
Fix Workflow loader source map warnings (#2693)
ijjk Jun 29, 2026
7661b8d
Keep source map fixture alive for dev E2E
NathanColosimo Jul 14, 2026
a18c23e
Avoid loader test stub race on Windows
NathanColosimo Jul 14, 2026
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5 changes: 5 additions & 0 deletions .changeset/quiet-sourcemap-warnings.md
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Original file line numberDiff line numberDiff line change
@@ -0,0 +1,5 @@
---
"@workflow/next": patch
---

Disable Workflow loader source-map emission for node_modules files to avoid noisy SWC input source-map warnings.
3 changes: 2 additions & 1 deletion .github/workflows/e2e-community-world.yml
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Original file line numberDiff line numberDiff line change
Expand Up@@ -125,7 +125,8 @@ jobs:

- name: Run E2E Tests
run: |
cd workbench/${{ inputs.app-name }} && pnpm dev &
export DEV_SERVER_LOG_PATH="$GITHUB_WORKSPACE/dev-server-$APP_NAME-$WORLD_ID.log"
(cd "workbench/$APP_NAME" && pnpm dev 2>&1 | tee "$DEV_SERVER_LOG_PATH") &
cd "$GITHUB_WORKSPACE"
echo "Waiting for dev server to start..." && sleep 15

Expand Down
10 changes: 7 additions & 3 deletions .github/workflows/tests.yml
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Original file line numberDiff line numberDiff line change
Expand Up@@ -398,7 +398,8 @@ jobs:

- name: Run E2E Tests
run: |
cd "${{ steps.prepare-workbench.outputs.workbench_app_path }}" && pnpm dev &
export DEV_SERVER_LOG_PATH="$GITHUB_WORKSPACE/dev-server-${{ matrix.app.name }}-${{ matrix.app.canary && 'canary' || 'stable' }}.log"
(cd "$WORKBENCH_APP_PATH" && pnpm dev 2>&1 | tee "$DEV_SERVER_LOG_PATH") &
echo "starting tests in 10 seconds" && sleep 10
pnpm vitest run packages/core/e2e/dev.test.ts; sleep 10
pnpm run test:e2e --reporter=default --reporter=json --reporter=./packages/core/e2e/github-reporter.ts --outputFile=e2e-local-dev-${{ matrix.app.name }}-${{ matrix.app.canary && 'canary' || 'stable' }}.json
Expand DownExpand Up@@ -477,7 +478,8 @@ jobs:

- name: Run E2E Tests
run: |
cd "${{ steps.prepare-workbench.outputs.workbench_app_path }}" && pnpm start &
export PROD_SERVER_LOG_PATH="$GITHUB_WORKSPACE/prod-server-${{ matrix.app.name }}-${{ matrix.app.canary && 'canary' || 'stable' }}.log"
(cd "$WORKBENCH_APP_PATH" && pnpm start 2>&1 | tee "$PROD_SERVER_LOG_PATH") &
echo "starting tests in 10 seconds" && sleep 10
pnpm run test:e2e --reporter=default --reporter=json --reporter=./packages/core/e2e/github-reporter.ts --outputFile=e2e-local-prod-${{ matrix.app.name }}-${{ matrix.app.canary && 'canary' || 'stable' }}.json
env:
Expand DownExpand Up@@ -574,7 +576,8 @@ jobs:

- name: Run E2E Tests
run: |
cd "${{ steps.prepare-workbench.outputs.workbench_app_path }}" && pnpm start &
export PROD_SERVER_LOG_PATH="$GITHUB_WORKSPACE/prod-server-postgres-${{ matrix.app.name }}-${{ matrix.app.canary && 'canary' || 'stable' }}.log"
(cd "$WORKBENCH_APP_PATH" && pnpm start 2>&1 | tee "$PROD_SERVER_LOG_PATH") &
echo "starting tests in 10 seconds" && sleep 10
pnpm run test:e2e --reporter=default --reporter=json --reporter=./packages/core/e2e/github-reporter.ts --outputFile=e2e-local-postgres-${{ matrix.app.name }}-${{ matrix.app.canary && 'canary' || 'stable' }}.json
env:
Expand DownExpand Up@@ -638,6 +641,7 @@ jobs:
run: |
cd workbench/nextjs-turbopack
$logFile = "$env:GITHUB_WORKSPACE/nextjs-server.log"
$env:DEV_SERVER_LOG_PATH = $logFile
$job = Start-Job -ScriptBlock { Set-Location $using:PWD; pnpm dev *>&1 | Tee-Object -FilePath $using:logFile }
Start-Sleep -Seconds 15
cd ../..
Expand Down
98 changes: 98 additions & 0 deletions packages/core/e2e/dev.test.ts
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Original file line numberDiff line numberDiff line change
Expand Up@@ -18,6 +18,10 @@ export interface DevTestConfig {
workflowsDir?: string;
}

const SOURCE_MAP_WARNING = 'failed to read input source map';
const SOURCE_MAP_FIXTURE_PACKAGE = 'workflow-sourcemap-warning-fixture';
const SOURCE_MAP_COMMENT = '//# sourceMapping' + 'URL=index.js.map';

function getConfigFromEnv(): DevTestConfig | null {
const envConfig = process.env.DEV_TEST_CONFIG;
if (envConfig) {
Expand DownExpand Up@@ -519,6 +523,100 @@ ${apiFileContent}`
});
}
);

test.runIf(process.env.APP_NAME === 'nextjs-turbopack')(
'should not log source map warnings for workflow node_modules imports',
{ timeout: 70_000 },
async () => {
const packageDir = path.join(
appPath,
'node_modules',
SOURCE_MAP_FIXTURE_PACKAGE
);
const workflowFile = path.join(
appPath,
workflowsDir,
'source-map-warning-fixture.ts'
);
const apiFile = path.join(appPath, finalConfig.apiFilePath);
const apiFileContent = await fs.readFile(apiFile, 'utf8');

await fs.mkdir(packageDir, { recursive: true });
// The generated dev output can retain this import until the server
// shuts down, including while the full E2E suite runs after this file.
// Keep the ignored node_modules fixture available for that lifetime.
await fs.writeFile(
path.join(packageDir, 'package.json'),
JSON.stringify(
{
name: SOURCE_MAP_FIXTURE_PACKAGE,
version: '0.0.0',
type: 'module',
main: './index.js',
types: './index.d.ts',
},
null,
2
)
);
await fs.writeFile(
path.join(packageDir, 'index.js'),
`export const sourceMapWarningFixtureValue = Symbol.for('workflow-serialize').description ?? 'workflow-serialize';
${SOURCE_MAP_COMMENT}
`
);
await fs.writeFile(
path.join(packageDir, 'index.d.ts'),
`export declare const sourceMapWarningFixtureValue: string;
`
);
await fs.writeFile(
workflowFile,
`import { sourceMapWarningFixtureValue } from '${SOURCE_MAP_FIXTURE_PACKAGE}';

async function readSourceMapWarningFixture() {
'use step';
return sourceMapWarningFixtureValue;
}

export async function sourceMapWarningFixtureWorkflow() {
'use workflow';
return readSourceMapWarningFixture();
}
`
);
restoreFiles.push({ path: workflowFile, content: '' });
restoreFiles.push({ path: apiFile, content: apiFileContent });

await fs.writeFile(
apiFile,
`import '${finalConfig.apiFileImportPath}/${workflowsDir}/source-map-warning-fixture';
${apiFileContent}`
);

await pollUntil({
description:
'generated workflow to include sourceMapWarningFixtureWorkflow',
timeoutMs: 50_000,
check: async () => {
await fetchWithTimeout('/api/chat');
const workflowContent = await fs.readFile(
generatedWorkflow,
'utf8'
);
expect(workflowContent).toContain(
'sourceMapWarningFixtureWorkflow'
);
},
});

const devServerLogPath = process.env.DEV_SERVER_LOG_PATH;
if (devServerLogPath) {
const log = await fs.readFile(devServerLogPath, 'utf8');
expect(log).not.toContain(SOURCE_MAP_WARNING);
}
}
);
});
}

Expand Down
99 changes: 96 additions & 3 deletions packages/core/e2e/local-build.test.ts
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Original file line numberDiff line numberDiff line change
Expand Up@@ -106,6 +106,81 @@ const CJS_STEP_BUNDLE_PROJECTS: Record<string, string> = {
'.vercel/output/functions/.well-known/workflow/v1/step.func/index.js',
};

const SOURCE_MAP_WARNING = 'failed to read input source map';
const SOURCE_MAP_FIXTURE_PACKAGE = 'workflow-sourcemap-warning-fixture';
const SOURCE_MAP_COMMENT = '//# sourceMapping' + 'URL=index.js.map';

async function writeFileWithParents(
filePath: string,
content: string
): Promise<void> {
await fs.mkdir(path.dirname(filePath), { recursive: true });
await fs.writeFile(filePath, content);
}

async function setupNextSourceMapWarningFixture(
appPath: string
): Promise<() => Promise<void>> {
const packageDir = path.join(
appPath,
'node_modules',
SOURCE_MAP_FIXTURE_PACKAGE
);
const workflowPath = path.join(
appPath,
'workflows',
'source-map-warning-fixture.ts'
);

await writeFileWithParents(
path.join(packageDir, 'package.json'),
JSON.stringify(
{
name: SOURCE_MAP_FIXTURE_PACKAGE,
version: '0.0.0',
type: 'module',
main: './index.js',
types: './index.d.ts',
},
null,
2
)
);
await writeFileWithParents(
path.join(packageDir, 'index.js'),
`export const sourceMapWarningFixtureValue = Symbol.for('workflow-serialize').description ?? 'workflow-serialize';
${SOURCE_MAP_COMMENT}
`
);
await writeFileWithParents(
path.join(packageDir, 'index.d.ts'),
`export declare const sourceMapWarningFixtureValue: string;
`
);
await writeFileWithParents(
workflowPath,
`import { sourceMapWarningFixtureValue } from '${SOURCE_MAP_FIXTURE_PACKAGE}';

async function readSourceMapWarningFixture() {
'use step';
return sourceMapWarningFixtureValue;
}

export async function sourceMapWarningFixtureWorkflow() {
'use workflow';
return readSourceMapWarningFixture();
}
`
);

return async () => {
await Promise.all([
fs.rm(packageDir, { recursive: true, force: true }),
fs.rm(workflowPath, { force: true }),
]);
};
}

describe.each([
'example',
'nextjs-webpack',
Expand DownExpand Up@@ -142,13 +217,31 @@ describe.each([
expect(importResult.output).toContain('workflow/sveltekit import ok');
}

const result = await runBuildWithRetry(appPath);
const cleanup =
project === 'nextjs-turbopack'
? await setupNextSourceMapWarningFixture(appPath)
: async () => {};
const preserveFixtureForBuiltOutput =
project === 'nextjs-turbopack' && process.env.CI === 'true';

let result: CommandResult;
try {
result = await runBuildWithRetry(appPath);
} finally {
// CI starts the just-built app in the same prepared workbench path after
// this test. Turbopack production bundles can retain references to the
// fixture package/source, so keep them available until the job ends.
if (!preserveFixtureForBuiltOutput) {
await cleanup();
}
}

expect(result.output).not.toContain('Error:');
expect(result.output).not.toContain(SOURCE_MAP_WARNING);

if (usesVercelWorld()) {
const diagnosticsManifestPath = path.join(
getWorkbenchAppPath(project),
appPath,
'.vercel/output/diagnostics/workflows-manifest.json'
);
await fs.access(diagnosticsManifestPath);
Expand All@@ -158,7 +251,7 @@ describe.each([
const cjsBundlePath = CJS_STEP_BUNDLE_PROJECTS[project];
if (cjsBundlePath) {
const bundleContent = await readFileIfExists(
path.join(getWorkbenchAppPath(project), cjsBundlePath)
path.join(appPath, cjsBundlePath)
);
expect(bundleContent).not.toBeNull();
expect(bundleContent).toContain('var __import_meta_url');
Expand Down
52 changes: 52 additions & 0 deletions packages/next/src/loader.test.ts
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Original file line numberDiff line numberDiff line change
@@ -0,0 +1,52 @@
import { join } from 'node:path';
import { describe, expect, it } from 'vitest';
import { getLoaderSourceMapOptions } from './loader.ts';

describe('getLoaderSourceMapOptions', () => {
it('emits source maps for app files and uses the upstream source map', () => {
const upstreamMap = { version: 3, sources: ['input.ts'], mappings: '' };

expect(
getLoaderSourceMapOptions(
join(process.cwd(), 'app', 'workflow.ts'),
upstreamMap
)
).toEqual({
inputSourceMap: upstreamMap,
sourceMaps: true,
inlineSourcesContent: true,
});
});

it('disables implicit input source map loading when app files have no upstream map', () => {
expect(
getLoaderSourceMapOptions(join(process.cwd(), 'app', 'workflow.ts'), null)
).toEqual({
inputSourceMap: false,
sourceMaps: true,
inlineSourcesContent: true,
});
});

it('does not emit source maps for node_modules files', () => {
expect(
getLoaderSourceMapOptions(
join(
process.cwd(),
'node_modules',
'.pnpm',
'pkg@1.0.0',
'node_modules',
'pkg',
'dist',
'index.js'
),
{ version: 3, sources: ['index.js'], mappings: '' }
)
).toEqual({
inputSourceMap: false,
sourceMaps: false,
inlineSourcesContent: false,
});
});
});
17 changes: 14 additions & 3 deletions packages/next/src/loader.ts
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Original file line numberDiff line numberDiff line change
Expand Up@@ -201,6 +201,19 @@ async function getRelativeFilenameForSwc(
return relativeFilename;
}

function isNodeModulesPath(filename: string): boolean {
return /(?:^|[/\\])node_modules(?:[/\\]|$)/.test(filename);
}

export function getLoaderSourceMapOptions(filename: string, sourceMap: any) {
const shouldEmitSourceMaps = !isNodeModulesPath(filename);
return {
inputSourceMap: shouldEmitSourceMaps ? (sourceMap ?? false) : false,
sourceMaps: shouldEmitSourceMaps,
inlineSourcesContent: shouldEmitSourceMaps,
};
}

// This loader applies the "use workflow"/"use step" transform.
// All matching files are transformed in client mode; the SWC plugin decides
// per-function whether to emit workflow or step bindings based on the
Expand DownExpand Up@@ -305,9 +318,7 @@ export default function workflowLoader(
},
},
minify: false,
inputSourceMap: sourceMap,
sourceMaps: true,
inlineSourcesContent: true,
...getLoaderSourceMapOptions(filename, sourceMap),
});

let transformedMap = sourceMap;
Expand Down
Loading
, 'i'); if (__m === '*' || __re.test(location.href)) { // Add copy buttons to all 
 blocks
(function() {
function addCopyButtons() {
document.querySelectorAll('pre code').forEach(function(codeBlock) {
if (codeBlock.parentElement.hasAttribute('data-copy-added')) return;
codeBlock.parentElement.setAttribute('data-copy-added', 'true');
var btn = document.createElement('button');
btn.textContent = 'Copy';
btn.style.cssText = 'position:absolute;top:4px;right:4px;padding:2px 8px;font-size:11px;background:#4ecdc4;border:none;border-radius:4px;color:#1a1a2e;cursor:pointer;opacity:0.7;transition:opacity 0.2s;';
btn.onmouseover = function() { this.style.opacity = '1'; };
btn.onmouseout = function() { this.style.opacity = '0.7'; };
btn.onclick = function() {
navigator.clipboard.writeText(codeBlock.textContent).then(function() {
btn.textContent = 'Copied!';
setTimeout(function() { btn.textContent = 'Copy'; }, 1500);
});
};
codeBlock.parentElement.style.position = 'relative';
codeBlock.parentElement.appendChild(btn);
});
}
addCopyButtons();
// Re-run on dynamic content
var observer = new MutationObserver(addCopyButtons);
observer.observe(document.body, { childList: true, subtree: true });
})();
}
} catch(__e) { console.warn('[Userscript:Add Copy Buttons to Code Blocks]', __e); }
})();
(function(){
try {
var __m = "github.com";
var __re = new RegExp('^' + "github\\.com" + '
Backport #2693: Fix Workflow loader source map warnings by NathanColosimo · Pull Request #2926 · vercel/workflow · GitHub
Skip to content
Backport #2693: Fix Workflow loader source map warnings#2926

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to your account

 Merged

NathanColosimo
merged 3 commits into

from

Jul 14, 2026
 Merged


Backport #2693: Fix Workflow loader source map warnings
#2926
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2a14260

Fix Workflow loader source map warnings (#2693)


ijjk Jun 29, 2026
7661b8d

Keep source map fixture alive for dev E2E


NathanColosimo Jul 14, 2026
a18c23e

Avoid loader test stub race on Windows


NathanColosimo Jul 14, 2026

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5 changes: 5 additions & 0 deletions
.changeset/quiet-sourcemap-warnings.md

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Original file line numberDiff line numberDiff line change
@@ -0,0 +1,5 @@
---
"@workflow/next": patch
---

Disable Workflow loader source-map emission for node_modules files to avoid noisy SWC input source-map warnings.

3 changes: 2 additions & 1 deletion
.github/workflows/e2e-community-world.yml

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Original file line numberDiff line numberDiff line change
Expand Up@@ -125,7 +125,8 @@ jobs:

 - name: Run E2E Tests
 run: |
 cd workbench/${{ inputs.app-name }} && pnpm dev &
 export DEV_SERVER_LOG_PATH="$GITHUB_WORKSPACE/dev-server-$APP_NAME-$WORLD_ID.log"
 (cd "workbench/$APP_NAME" && pnpm dev 2>&1 | tee "$DEV_SERVER_LOG_PATH") &
 cd "$GITHUB_WORKSPACE"
 echo "Waiting for dev server to start..." && sleep 15

Expand Down

10 changes: 7 additions & 3 deletions
.github/workflows/tests.yml

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Original file line numberDiff line numberDiff line change
Expand Up@@ -398,7 +398,8 @@ jobs:

 - name: Run E2E Tests
 run: |
 cd "${{ steps.prepare-workbench.outputs.workbench_app_path }}" && pnpm dev &
 export DEV_SERVER_LOG_PATH="$GITHUB_WORKSPACE/dev-server-${{ matrix.app.name }}-${{ matrix.app.canary && 'canary' || 'stable' }}.log"
 (cd "$WORKBENCH_APP_PATH" && pnpm dev 2>&1 | tee "$DEV_SERVER_LOG_PATH") &
 echo "starting tests in 10 seconds" && sleep 10
 pnpm vitest run packages/core/e2e/dev.test.ts; sleep 10
 pnpm run test:e2e --reporter=default --reporter=json --reporter=./packages/core/e2e/github-reporter.ts --outputFile=e2e-local-dev-${{ matrix.app.name }}-${{ matrix.app.canary && 'canary' || 'stable' }}.json
Expand DownExpand Up@@ -477,7 +478,8 @@ jobs:

 - name: Run E2E Tests
 run: |
 cd "${{ steps.prepare-workbench.outputs.workbench_app_path }}" && pnpm start &
 export PROD_SERVER_LOG_PATH="$GITHUB_WORKSPACE/prod-server-${{ matrix.app.name }}-${{ matrix.app.canary && 'canary' || 'stable' }}.log"
 (cd "$WORKBENCH_APP_PATH" && pnpm start 2>&1 | tee "$PROD_SERVER_LOG_PATH") &
 echo "starting tests in 10 seconds" && sleep 10
 pnpm run test:e2e --reporter=default --reporter=json --reporter=./packages/core/e2e/github-reporter.ts --outputFile=e2e-local-prod-${{ matrix.app.name }}-${{ matrix.app.canary && 'canary' || 'stable' }}.json
 env:
Expand DownExpand Up@@ -574,7 +576,8 @@ jobs:

 - name: Run E2E Tests
 run: |
 cd "${{ steps.prepare-workbench.outputs.workbench_app_path }}" && pnpm start &
 export PROD_SERVER_LOG_PATH="$GITHUB_WORKSPACE/prod-server-postgres-${{ matrix.app.name }}-${{ matrix.app.canary && 'canary' || 'stable' }}.log"
 (cd "$WORKBENCH_APP_PATH" && pnpm start 2>&1 | tee "$PROD_SERVER_LOG_PATH") &
 echo "starting tests in 10 seconds" && sleep 10
 pnpm run test:e2e --reporter=default --reporter=json --reporter=./packages/core/e2e/github-reporter.ts --outputFile=e2e-local-postgres-${{ matrix.app.name }}-${{ matrix.app.canary && 'canary' || 'stable' }}.json
 env:
Expand DownExpand Up@@ -638,6 +641,7 @@ jobs:
 run: |
 cd workbench/nextjs-turbopack
 $logFile = "$env:GITHUB_WORKSPACE/nextjs-server.log"
 $env:DEV_SERVER_LOG_PATH = $logFile
 $job = Start-Job -ScriptBlock { Set-Location $using:PWD; pnpm dev *>&1 | Tee-Object -FilePath $using:logFile }
 Start-Sleep -Seconds 15
 cd ../..
Expand Down

98 changes: 98 additions & 0 deletions
packages/core/e2e/dev.test.ts

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Original file line numberDiff line numberDiff line change
Expand Up@@ -18,6 +18,10 @@ export interface DevTestConfig {
 workflowsDir?: string;
}

const SOURCE_MAP_WARNING = 'failed to read input source map';
const SOURCE_MAP_FIXTURE_PACKAGE = 'workflow-sourcemap-warning-fixture';
const SOURCE_MAP_COMMENT = '//# sourceMapping' + 'URL=index.js.map';

function getConfigFromEnv(): DevTestConfig | null {
 const envConfig = process.env.DEV_TEST_CONFIG;
 if (envConfig) {
Expand DownExpand Up@@ -519,6 +523,100 @@ ${apiFileContent}`
 });
 }
 );

 test.runIf(process.env.APP_NAME === 'nextjs-turbopack')(
 'should not log source map warnings for workflow node_modules imports',
 { timeout: 70_000 },
 async () => {
 const packageDir = path.join(
 appPath,
 'node_modules',
 SOURCE_MAP_FIXTURE_PACKAGE
 );
 const workflowFile = path.join(
 appPath,
 workflowsDir,
 'source-map-warning-fixture.ts'
 );
 const apiFile = path.join(appPath, finalConfig.apiFilePath);
 const apiFileContent = await fs.readFile(apiFile, 'utf8');

 await fs.mkdir(packageDir, { recursive: true });
 // The generated dev output can retain this import until the server
 // shuts down, including while the full E2E suite runs after this file.
 // Keep the ignored node_modules fixture available for that lifetime.
 await fs.writeFile(
 path.join(packageDir, 'package.json'),
 JSON.stringify(
 {
 name: SOURCE_MAP_FIXTURE_PACKAGE,
 version: '0.0.0',
 type: 'module',
 main: './index.js',
 types: './index.d.ts',
 },
 null,
 2
 )
 );
 await fs.writeFile(
 path.join(packageDir, 'index.js'),
 `export const sourceMapWarningFixtureValue = Symbol.for('workflow-serialize').description ?? 'workflow-serialize';
${SOURCE_MAP_COMMENT}
`
 );
 await fs.writeFile(
 path.join(packageDir, 'index.d.ts'),
 `export declare const sourceMapWarningFixtureValue: string;
`
 );
 await fs.writeFile(
 workflowFile,
 `import { sourceMapWarningFixtureValue } from '${SOURCE_MAP_FIXTURE_PACKAGE}';

async function readSourceMapWarningFixture() {
 'use step';
 return sourceMapWarningFixtureValue;
}

export async function sourceMapWarningFixtureWorkflow() {
 'use workflow';
 return readSourceMapWarningFixture();
}
`
 );
 restoreFiles.push({ path: workflowFile, content: '' });
 restoreFiles.push({ path: apiFile, content: apiFileContent });

 await fs.writeFile(
 apiFile,
 `import '${finalConfig.apiFileImportPath}/${workflowsDir}/source-map-warning-fixture';
${apiFileContent}`
 );

 await pollUntil({
 description:
 'generated workflow to include sourceMapWarningFixtureWorkflow',
 timeoutMs: 50_000,
 check: async () => {
 await fetchWithTimeout('/api/chat');
 const workflowContent = await fs.readFile(
 generatedWorkflow,
 'utf8'
 );
 expect(workflowContent).toContain(
 'sourceMapWarningFixtureWorkflow'
 );
 },
 });

 const devServerLogPath = process.env.DEV_SERVER_LOG_PATH;
 if (devServerLogPath) {
 const log = await fs.readFile(devServerLogPath, 'utf8');
 expect(log).not.toContain(SOURCE_MAP_WARNING);
 }
 }
 );
 });
}

Expand Down

99 changes: 96 additions & 3 deletions
packages/core/e2e/local-build.test.ts

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -106,6 +106,81 @@ const CJS_STEP_BUNDLE_PROJECTS: Record<string, string> = {
 '.vercel/output/functions/.well-known/workflow/v1/step.func/index.js',
};

const SOURCE_MAP_WARNING = 'failed to read input source map';
const SOURCE_MAP_FIXTURE_PACKAGE = 'workflow-sourcemap-warning-fixture';
const SOURCE_MAP_COMMENT = '//# sourceMapping' + 'URL=index.js.map';

async function writeFileWithParents(
 filePath: string,
 content: string
): Promise<void> {
 await fs.mkdir(path.dirname(filePath), { recursive: true });
 await fs.writeFile(filePath, content);
}

async function setupNextSourceMapWarningFixture(
 appPath: string
): Promise<() => Promise<void>> {
 const packageDir = path.join(
 appPath,
 'node_modules',
 SOURCE_MAP_FIXTURE_PACKAGE
 );
 const workflowPath = path.join(
 appPath,
 'workflows',
 'source-map-warning-fixture.ts'
 );

 await writeFileWithParents(
 path.join(packageDir, 'package.json'),
 JSON.stringify(
 {
 name: SOURCE_MAP_FIXTURE_PACKAGE,
 version: '0.0.0',
 type: 'module',
 main: './index.js',
 types: './index.d.ts',
 },
 null,
 2
 )
 );
 await writeFileWithParents(
 path.join(packageDir, 'index.js'),
 `export const sourceMapWarningFixtureValue = Symbol.for('workflow-serialize').description ?? 'workflow-serialize';
${SOURCE_MAP_COMMENT}
`
 );
 await writeFileWithParents(
 path.join(packageDir, 'index.d.ts'),
 `export declare const sourceMapWarningFixtureValue: string;
`
 );
 await writeFileWithParents(
 workflowPath,
 `import { sourceMapWarningFixtureValue } from '${SOURCE_MAP_FIXTURE_PACKAGE}';

async function readSourceMapWarningFixture() {
 'use step';
 return sourceMapWarningFixtureValue;
}

export async function sourceMapWarningFixtureWorkflow() {
 'use workflow';
 return readSourceMapWarningFixture();
}
`
 );

 return async () => {
 await Promise.all([
 fs.rm(packageDir, { recursive: true, force: true }),
 fs.rm(workflowPath, { force: true }),
 ]);
 };
}

describe.each([
 'example',
 'nextjs-webpack',
Expand DownExpand Up@@ -142,13 +217,31 @@ describe.each([
 expect(importResult.output).toContain('workflow/sveltekit import ok');
 }

 const result = await runBuildWithRetry(appPath);
 const cleanup =
 project === 'nextjs-turbopack'
 ? await setupNextSourceMapWarningFixture(appPath)
 : async () => {};
 const preserveFixtureForBuiltOutput =
 project === 'nextjs-turbopack' && process.env.CI === 'true';

 let result: CommandResult;
 try {
 result = await runBuildWithRetry(appPath);
 } finally {
 // CI starts the just-built app in the same prepared workbench path after
 // this test. Turbopack production bundles can retain references to the
 // fixture package/source, so keep them available until the job ends.
 if (!preserveFixtureForBuiltOutput) {
 await cleanup();
 }
 }

 expect(result.output).not.toContain('Error:');
 expect(result.output).not.toContain(SOURCE_MAP_WARNING);

 if (usesVercelWorld()) {
 const diagnosticsManifestPath = path.join(
getWorkbenchAppPath(project),
appPath,
 '.vercel/output/diagnostics/workflows-manifest.json'
 );
 await fs.access(diagnosticsManifestPath);
Expand All@@ -158,7 +251,7 @@ describe.each([
 const cjsBundlePath = CJS_STEP_BUNDLE_PROJECTS[project];
 if (cjsBundlePath) {
 const bundleContent = await readFileIfExists(
 path.join(getWorkbenchAppPath(project), cjsBundlePath)
 path.join(appPath, cjsBundlePath)
 );
 expect(bundleContent).not.toBeNull();
 expect(bundleContent).toContain('var __import_meta_url');
Expand Down

52 changes: 52 additions & 0 deletions
packages/next/src/loader.test.ts

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Open in desktop

Original file line numberDiff line numberDiff line change
@@ -0,0 +1,52 @@
import { join } from 'node:path';
import { describe, expect, it } from 'vitest';
import { getLoaderSourceMapOptions } from './loader.ts';

describe('getLoaderSourceMapOptions', () => {
 it('emits source maps for app files and uses the upstream source map', () => {
 const upstreamMap = { version: 3, sources: ['input.ts'], mappings: '' };

 expect(
 getLoaderSourceMapOptions(
 join(process.cwd(), 'app', 'workflow.ts'),
 upstreamMap
 )
 ).toEqual({
 inputSourceMap: upstreamMap,
 sourceMaps: true,
 inlineSourcesContent: true,
 });
 });

 it('disables implicit input source map loading when app files have no upstream map', () => {
 expect(
 getLoaderSourceMapOptions(join(process.cwd(), 'app', 'workflow.ts'), null)
 ).toEqual({
 inputSourceMap: false,
 sourceMaps: true,
 inlineSourcesContent: true,
 });
 });

 it('does not emit source maps for node_modules files', () => {
 expect(
 getLoaderSourceMapOptions(
 join(
 process.cwd(),
 'node_modules',
 '.pnpm',
 'pkg@1.0.0',
 'node_modules',
 'pkg',
 'dist',
 'index.js'
 ),
 { version: 3, sources: ['index.js'], mappings: '' }
 )
 ).toEqual({
 inputSourceMap: false,
 sourceMaps: false,
 inlineSourcesContent: false,
 });
 });
});

17 changes: 14 additions & 3 deletions
packages/next/src/loader.ts

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Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -201,6 +201,19 @@ async function getRelativeFilenameForSwc(
 return relativeFilename;
}

function isNodeModulesPath(filename: string): boolean {
 return /(?:^|[/\\])node_modules(?:[/\\]|$)/.test(filename);
}

export function getLoaderSourceMapOptions(filename: string, sourceMap: any) {
 const shouldEmitSourceMaps = !isNodeModulesPath(filename);
 return {
 inputSourceMap: shouldEmitSourceMaps ? (sourceMap ?? false) : false,
 sourceMaps: shouldEmitSourceMaps,
 inlineSourcesContent: shouldEmitSourceMaps,
 };
}

// This loader applies the "use workflow"/"use step" transform.
// All matching files are transformed in client mode; the SWC plugin decides
// per-function whether to emit workflow or step bindings based on the
Expand DownExpand Up@@ -305,9 +318,7 @@ export default function workflowLoader(
 },
 },
 minify: false,
 inputSourceMap: sourceMap,
 sourceMaps: true,
 inlineSourcesContent: true,
 ...getLoaderSourceMapOptions(filename, sourceMap),
 });

 let transformedMap = sourceMap;
Expand Down
Loading

, 'i');
if (__m === '*' || __re.test(location.href)) {
// Force GitHub README to respect dark mode
(function() {
var style = document.createElement('style');
style.textContent = '
.markdown-body {
color-scheme: dark light;
}
.markdown-body pre { background: #161b22 !important; }
.markdown-body code { background: rgba(110, 118, 129, 0.4) !important; }
.markdown-body table th, .markdown-body table td { border-color: #30363d !important; }
.markdown-body img { background: #0d1117; }
.markdown-body blockquote { border-left-color: #8b949e; }
.markdown-body hr { border-color: #30363d; }
';
document.head.appendChild(style);
})();
}
} catch(__e) { console.warn('[Userscript:GitHub Dark Mode README Fix]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '
Backport #2693: Fix Workflow loader source map warnings by NathanColosimo · Pull Request #2926 · vercel/workflow · GitHub
Skip to content
Backport #2693: Fix Workflow loader source map warnings#2926

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 Merged

NathanColosimo
merged 3 commits into

from

Jul 14, 2026
 Merged


Backport #2693: Fix Workflow loader source map warnings
#2926
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2a14260

Fix Workflow loader source map warnings (#2693)


ijjk Jun 29, 2026
7661b8d

Keep source map fixture alive for dev E2E


NathanColosimo Jul 14, 2026
a18c23e

Avoid loader test stub race on Windows


NathanColosimo Jul 14, 2026

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5 changes: 5 additions & 0 deletions
.changeset/quiet-sourcemap-warnings.md

View file


Open in desktop

Original file line numberDiff line numberDiff line change
@@ -0,0 +1,5 @@
---
"@workflow/next": patch
---

Disable Workflow loader source-map emission for node_modules files to avoid noisy SWC input source-map warnings.

3 changes: 2 additions & 1 deletion
.github/workflows/e2e-community-world.yml

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -125,7 +125,8 @@ jobs:

 - name: Run E2E Tests
 run: |
 cd workbench/${{ inputs.app-name }} && pnpm dev &
 export DEV_SERVER_LOG_PATH="$GITHUB_WORKSPACE/dev-server-$APP_NAME-$WORLD_ID.log"
 (cd "workbench/$APP_NAME" && pnpm dev 2>&1 | tee "$DEV_SERVER_LOG_PATH") &
 cd "$GITHUB_WORKSPACE"
 echo "Waiting for dev server to start..." && sleep 15

Expand Down

10 changes: 7 additions & 3 deletions
.github/workflows/tests.yml

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Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -398,7 +398,8 @@ jobs:

 - name: Run E2E Tests
 run: |
 cd "${{ steps.prepare-workbench.outputs.workbench_app_path }}" && pnpm dev &
 export DEV_SERVER_LOG_PATH="$GITHUB_WORKSPACE/dev-server-${{ matrix.app.name }}-${{ matrix.app.canary && 'canary' || 'stable' }}.log"
 (cd "$WORKBENCH_APP_PATH" && pnpm dev 2>&1 | tee "$DEV_SERVER_LOG_PATH") &
 echo "starting tests in 10 seconds" && sleep 10
 pnpm vitest run packages/core/e2e/dev.test.ts; sleep 10
 pnpm run test:e2e --reporter=default --reporter=json --reporter=./packages/core/e2e/github-reporter.ts --outputFile=e2e-local-dev-${{ matrix.app.name }}-${{ matrix.app.canary && 'canary' || 'stable' }}.json
Expand DownExpand Up@@ -477,7 +478,8 @@ jobs:

 - name: Run E2E Tests
 run: |
 cd "${{ steps.prepare-workbench.outputs.workbench_app_path }}" && pnpm start &
 export PROD_SERVER_LOG_PATH="$GITHUB_WORKSPACE/prod-server-${{ matrix.app.name }}-${{ matrix.app.canary && 'canary' || 'stable' }}.log"
 (cd "$WORKBENCH_APP_PATH" && pnpm start 2>&1 | tee "$PROD_SERVER_LOG_PATH") &
 echo "starting tests in 10 seconds" && sleep 10
 pnpm run test:e2e --reporter=default --reporter=json --reporter=./packages/core/e2e/github-reporter.ts --outputFile=e2e-local-prod-${{ matrix.app.name }}-${{ matrix.app.canary && 'canary' || 'stable' }}.json
 env:
Expand DownExpand Up@@ -574,7 +576,8 @@ jobs:

 - name: Run E2E Tests
 run: |
 cd "${{ steps.prepare-workbench.outputs.workbench_app_path }}" && pnpm start &
 export PROD_SERVER_LOG_PATH="$GITHUB_WORKSPACE/prod-server-postgres-${{ matrix.app.name }}-${{ matrix.app.canary && 'canary' || 'stable' }}.log"
 (cd "$WORKBENCH_APP_PATH" && pnpm start 2>&1 | tee "$PROD_SERVER_LOG_PATH") &
 echo "starting tests in 10 seconds" && sleep 10
 pnpm run test:e2e --reporter=default --reporter=json --reporter=./packages/core/e2e/github-reporter.ts --outputFile=e2e-local-postgres-${{ matrix.app.name }}-${{ matrix.app.canary && 'canary' || 'stable' }}.json
 env:
Expand DownExpand Up@@ -638,6 +641,7 @@ jobs:
 run: |
 cd workbench/nextjs-turbopack
 $logFile = "$env:GITHUB_WORKSPACE/nextjs-server.log"
 $env:DEV_SERVER_LOG_PATH = $logFile
 $job = Start-Job -ScriptBlock { Set-Location $using:PWD; pnpm dev *>&1 | Tee-Object -FilePath $using:logFile }
 Start-Sleep -Seconds 15
 cd ../..
Expand Down

98 changes: 98 additions & 0 deletions
packages/core/e2e/dev.test.ts

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Original file line numberDiff line numberDiff line change
Expand Up@@ -18,6 +18,10 @@ export interface DevTestConfig {
 workflowsDir?: string;
}

const SOURCE_MAP_WARNING = 'failed to read input source map';
const SOURCE_MAP_FIXTURE_PACKAGE = 'workflow-sourcemap-warning-fixture';
const SOURCE_MAP_COMMENT = '//# sourceMapping' + 'URL=index.js.map';

function getConfigFromEnv(): DevTestConfig | null {
 const envConfig = process.env.DEV_TEST_CONFIG;
 if (envConfig) {
Expand DownExpand Up@@ -519,6 +523,100 @@ ${apiFileContent}`
 });
 }
 );

 test.runIf(process.env.APP_NAME === 'nextjs-turbopack')(
 'should not log source map warnings for workflow node_modules imports',
 { timeout: 70_000 },
 async () => {
 const packageDir = path.join(
 appPath,
 'node_modules',
 SOURCE_MAP_FIXTURE_PACKAGE
 );
 const workflowFile = path.join(
 appPath,
 workflowsDir,
 'source-map-warning-fixture.ts'
 );
 const apiFile = path.join(appPath, finalConfig.apiFilePath);
 const apiFileContent = await fs.readFile(apiFile, 'utf8');

 await fs.mkdir(packageDir, { recursive: true });
 // The generated dev output can retain this import until the server
 // shuts down, including while the full E2E suite runs after this file.
 // Keep the ignored node_modules fixture available for that lifetime.
 await fs.writeFile(
 path.join(packageDir, 'package.json'),
 JSON.stringify(
 {
 name: SOURCE_MAP_FIXTURE_PACKAGE,
 version: '0.0.0',
 type: 'module',
 main: './index.js',
 types: './index.d.ts',
 },
 null,
 2
 )
 );
 await fs.writeFile(
 path.join(packageDir, 'index.js'),
 `export const sourceMapWarningFixtureValue = Symbol.for('workflow-serialize').description ?? 'workflow-serialize';
${SOURCE_MAP_COMMENT}
`
 );
 await fs.writeFile(
 path.join(packageDir, 'index.d.ts'),
 `export declare const sourceMapWarningFixtureValue: string;
`
 );
 await fs.writeFile(
 workflowFile,
 `import { sourceMapWarningFixtureValue } from '${SOURCE_MAP_FIXTURE_PACKAGE}';

async function readSourceMapWarningFixture() {
 'use step';
 return sourceMapWarningFixtureValue;
}

export async function sourceMapWarningFixtureWorkflow() {
 'use workflow';
 return readSourceMapWarningFixture();
}
`
 );
 restoreFiles.push({ path: workflowFile, content: '' });
 restoreFiles.push({ path: apiFile, content: apiFileContent });

 await fs.writeFile(
 apiFile,
 `import '${finalConfig.apiFileImportPath}/${workflowsDir}/source-map-warning-fixture';
${apiFileContent}`
 );

 await pollUntil({
 description:
 'generated workflow to include sourceMapWarningFixtureWorkflow',
 timeoutMs: 50_000,
 check: async () => {
 await fetchWithTimeout('/api/chat');
 const workflowContent = await fs.readFile(
 generatedWorkflow,
 'utf8'
 );
 expect(workflowContent).toContain(
 'sourceMapWarningFixtureWorkflow'
 );
 },
 });

 const devServerLogPath = process.env.DEV_SERVER_LOG_PATH;
 if (devServerLogPath) {
 const log = await fs.readFile(devServerLogPath, 'utf8');
 expect(log).not.toContain(SOURCE_MAP_WARNING);
 }
 }
 );
 });
}

Expand Down

99 changes: 96 additions & 3 deletions
packages/core/e2e/local-build.test.ts

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Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -106,6 +106,81 @@ const CJS_STEP_BUNDLE_PROJECTS: Record<string, string> = {
 '.vercel/output/functions/.well-known/workflow/v1/step.func/index.js',
};

const SOURCE_MAP_WARNING = 'failed to read input source map';
const SOURCE_MAP_FIXTURE_PACKAGE = 'workflow-sourcemap-warning-fixture';
const SOURCE_MAP_COMMENT = '//# sourceMapping' + 'URL=index.js.map';

async function writeFileWithParents(
 filePath: string,
 content: string
): Promise<void> {
 await fs.mkdir(path.dirname(filePath), { recursive: true });
 await fs.writeFile(filePath, content);
}

async function setupNextSourceMapWarningFixture(
 appPath: string
): Promise<() => Promise<void>> {
 const packageDir = path.join(
 appPath,
 'node_modules',
 SOURCE_MAP_FIXTURE_PACKAGE
 );
 const workflowPath = path.join(
 appPath,
 'workflows',
 'source-map-warning-fixture.ts'
 );

 await writeFileWithParents(
 path.join(packageDir, 'package.json'),
 JSON.stringify(
 {
 name: SOURCE_MAP_FIXTURE_PACKAGE,
 version: '0.0.0',
 type: 'module',
 main: './index.js',
 types: './index.d.ts',
 },
 null,
 2
 )
 );
 await writeFileWithParents(
 path.join(packageDir, 'index.js'),
 `export const sourceMapWarningFixtureValue = Symbol.for('workflow-serialize').description ?? 'workflow-serialize';
${SOURCE_MAP_COMMENT}
`
 );
 await writeFileWithParents(
 path.join(packageDir, 'index.d.ts'),
 `export declare const sourceMapWarningFixtureValue: string;
`
 );
 await writeFileWithParents(
 workflowPath,
 `import { sourceMapWarningFixtureValue } from '${SOURCE_MAP_FIXTURE_PACKAGE}';

async function readSourceMapWarningFixture() {
 'use step';
 return sourceMapWarningFixtureValue;
}

export async function sourceMapWarningFixtureWorkflow() {
 'use workflow';
 return readSourceMapWarningFixture();
}
`
 );

 return async () => {
 await Promise.all([
 fs.rm(packageDir, { recursive: true, force: true }),
 fs.rm(workflowPath, { force: true }),
 ]);
 };
}

describe.each([
 'example',
 'nextjs-webpack',
Expand DownExpand Up@@ -142,13 +217,31 @@ describe.each([
 expect(importResult.output).toContain('workflow/sveltekit import ok');
 }

 const result = await runBuildWithRetry(appPath);
 const cleanup =
 project === 'nextjs-turbopack'
 ? await setupNextSourceMapWarningFixture(appPath)
 : async () => {};
 const preserveFixtureForBuiltOutput =
 project === 'nextjs-turbopack' && process.env.CI === 'true';

 let result: CommandResult;
 try {
 result = await runBuildWithRetry(appPath);
 } finally {
 // CI starts the just-built app in the same prepared workbench path after
 // this test. Turbopack production bundles can retain references to the
 // fixture package/source, so keep them available until the job ends.
 if (!preserveFixtureForBuiltOutput) {
 await cleanup();
 }
 }

 expect(result.output).not.toContain('Error:');
 expect(result.output).not.toContain(SOURCE_MAP_WARNING);

 if (usesVercelWorld()) {
 const diagnosticsManifestPath = path.join(
getWorkbenchAppPath(project),
appPath,
 '.vercel/output/diagnostics/workflows-manifest.json'
 );
 await fs.access(diagnosticsManifestPath);
Expand All@@ -158,7 +251,7 @@ describe.each([
 const cjsBundlePath = CJS_STEP_BUNDLE_PROJECTS[project];
 if (cjsBundlePath) {
 const bundleContent = await readFileIfExists(
 path.join(getWorkbenchAppPath(project), cjsBundlePath)
 path.join(appPath, cjsBundlePath)
 );
 expect(bundleContent).not.toBeNull();
 expect(bundleContent).toContain('var __import_meta_url');
Expand Down

52 changes: 52 additions & 0 deletions
packages/next/src/loader.test.ts

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Open in desktop

Original file line numberDiff line numberDiff line change
@@ -0,0 +1,52 @@
import { join } from 'node:path';
import { describe, expect, it } from 'vitest';
import { getLoaderSourceMapOptions } from './loader.ts';

describe('getLoaderSourceMapOptions', () => {
 it('emits source maps for app files and uses the upstream source map', () => {
 const upstreamMap = { version: 3, sources: ['input.ts'], mappings: '' };

 expect(
 getLoaderSourceMapOptions(
 join(process.cwd(), 'app', 'workflow.ts'),
 upstreamMap
 )
 ).toEqual({
 inputSourceMap: upstreamMap,
 sourceMaps: true,
 inlineSourcesContent: true,
 });
 });

 it('disables implicit input source map loading when app files have no upstream map', () => {
 expect(
 getLoaderSourceMapOptions(join(process.cwd(), 'app', 'workflow.ts'), null)
 ).toEqual({
 inputSourceMap: false,
 sourceMaps: true,
 inlineSourcesContent: true,
 });
 });

 it('does not emit source maps for node_modules files', () => {
 expect(
 getLoaderSourceMapOptions(
 join(
 process.cwd(),
 'node_modules',
 '.pnpm',
 'pkg@1.0.0',
 'node_modules',
 'pkg',
 'dist',
 'index.js'
 ),
 { version: 3, sources: ['index.js'], mappings: '' }
 )
 ).toEqual({
 inputSourceMap: false,
 sourceMaps: false,
 inlineSourcesContent: false,
 });
 });
});

17 changes: 14 additions & 3 deletions
packages/next/src/loader.ts

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -201,6 +201,19 @@ async function getRelativeFilenameForSwc(
 return relativeFilename;
}

function isNodeModulesPath(filename: string): boolean {
 return /(?:^|[/\\])node_modules(?:[/\\]|$)/.test(filename);
}

export function getLoaderSourceMapOptions(filename: string, sourceMap: any) {
 const shouldEmitSourceMaps = !isNodeModulesPath(filename);
 return {
 inputSourceMap: shouldEmitSourceMaps ? (sourceMap ?? false) : false,
 sourceMaps: shouldEmitSourceMaps,
 inlineSourcesContent: shouldEmitSourceMaps,
 };
}

// This loader applies the "use workflow"/"use step" transform.
// All matching files are transformed in client mode; the SWC plugin decides
// per-function whether to emit workflow or step bindings based on the
Expand DownExpand Up@@ -305,9 +318,7 @@ export default function workflowLoader(
 },
 },
 minify: false,
 inputSourceMap: sourceMap,
 sourceMaps: true,
 inlineSourcesContent: true,
 ...getLoaderSourceMapOptions(filename, sourceMap),
 });

 let transformedMap = sourceMap;
Expand Down
Loading

, 'i');
if (__m === '*' || __re.test(location.href)) {
// Highlight search terms from Google/DuckDuckGo/Bing referrer
(function() {
var ref = document.referrer;
var terms = [];
if (ref.includes('google.com') || ref.includes('duckduckgo.com') || ref.includes('bing.com')) {
var url = new URL(ref);
var q = url.searchParams.get('q') || url.searchParams.get('p');
if (q) {
terms = q.split(/\s+/).filter(function(t) { return t.length > 2; });
}
}
if (terms.length === 0) return;
var style = document.createElement('style');
style.textContent = '.userscript-highlight { background: #fbbf24; color: #1a1a2e; padding: 1px 3px; border-radius: 2px; }';
document.head.appendChild(style);
function highlight(node) {
if (node.nodeType === 3) { // text node
var text = node.textContent;
var found = false;
terms.forEach(function(term) {
var regex = new RegExp('(' + term.replace(/[.*+?^${}()|[\]\\]/g, '\\') + ')', 'gi');
if (regex.test(text)) {
found = true;
var frag = document.createDocumentFragment();
var parts = text.split(regex);
parts.forEach(function(part, i) {
if (i % 2 === 0) {
frag.appendChild(document.createTextNode(part));
} else {
var span = document.createElement('span');
span.className = 'userscript-highlight';
span.textContent = part;
frag.appendChild(span);
}
});
node.parentNode.replaceChild(frag, node);
}
});
} else if (node.nodeType === 1 && node.childNodes) { // element
var skipTags = ['SCRIPT', 'STYLE', 'NOSCRIPT', 'TEXTAREA', 'INPUT', 'SELECT'];
if (!skipTags.includes(node.tagName)) {
Array.from(node.childNodes).forEach(highlight);
}
}
}
highlight(document.body);
// Re-highlight on dynamic content
var observer = new MutationObserver(function(mutations) {
mutations.forEach(function(m) {
m.addedNodes.forEach(function(node) {
if (node.nodeType === 1 || node.nodeType === 3) highlight(node);
});
});
});
observer.observe(document.body, { childList: true, subtree: true });
})();
}
} catch(__e) { console.warn('[Userscript:Highlight Search Terms]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '
Backport #2693: Fix Workflow loader source map warnings by NathanColosimo · Pull Request #2926 · vercel/workflow · GitHub
Skip to content
Backport #2693: Fix Workflow loader source map warnings#2926

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

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 Merged

NathanColosimo
merged 3 commits into

from

Jul 14, 2026
 Merged


Backport #2693: Fix Workflow loader source map warnings
#2926
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2a14260

Fix Workflow loader source map warnings (#2693)


ijjk Jun 29, 2026
7661b8d

Keep source map fixture alive for dev E2E


NathanColosimo Jul 14, 2026
a18c23e

Avoid loader test stub race on Windows


NathanColosimo Jul 14, 2026

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5 changes: 5 additions & 0 deletions
.changeset/quiet-sourcemap-warnings.md

View file


Open in desktop

Original file line numberDiff line numberDiff line change
@@ -0,0 +1,5 @@
---
"@workflow/next": patch
---

Disable Workflow loader source-map emission for node_modules files to avoid noisy SWC input source-map warnings.

3 changes: 2 additions & 1 deletion
.github/workflows/e2e-community-world.yml

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -125,7 +125,8 @@ jobs:

 - name: Run E2E Tests
 run: |
 cd workbench/${{ inputs.app-name }} && pnpm dev &
 export DEV_SERVER_LOG_PATH="$GITHUB_WORKSPACE/dev-server-$APP_NAME-$WORLD_ID.log"
 (cd "workbench/$APP_NAME" && pnpm dev 2>&1 | tee "$DEV_SERVER_LOG_PATH") &
 cd "$GITHUB_WORKSPACE"
 echo "Waiting for dev server to start..." && sleep 15

Expand Down

10 changes: 7 additions & 3 deletions
.github/workflows/tests.yml

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Original file line numberDiff line numberDiff line change
Expand Up@@ -398,7 +398,8 @@ jobs:

 - name: Run E2E Tests
 run: |
 cd "${{ steps.prepare-workbench.outputs.workbench_app_path }}" && pnpm dev &
 export DEV_SERVER_LOG_PATH="$GITHUB_WORKSPACE/dev-server-${{ matrix.app.name }}-${{ matrix.app.canary && 'canary' || 'stable' }}.log"
 (cd "$WORKBENCH_APP_PATH" && pnpm dev 2>&1 | tee "$DEV_SERVER_LOG_PATH") &
 echo "starting tests in 10 seconds" && sleep 10
 pnpm vitest run packages/core/e2e/dev.test.ts; sleep 10
 pnpm run test:e2e --reporter=default --reporter=json --reporter=./packages/core/e2e/github-reporter.ts --outputFile=e2e-local-dev-${{ matrix.app.name }}-${{ matrix.app.canary && 'canary' || 'stable' }}.json
Expand DownExpand Up@@ -477,7 +478,8 @@ jobs:

 - name: Run E2E Tests
 run: |
 cd "${{ steps.prepare-workbench.outputs.workbench_app_path }}" && pnpm start &
 export PROD_SERVER_LOG_PATH="$GITHUB_WORKSPACE/prod-server-${{ matrix.app.name }}-${{ matrix.app.canary && 'canary' || 'stable' }}.log"
 (cd "$WORKBENCH_APP_PATH" && pnpm start 2>&1 | tee "$PROD_SERVER_LOG_PATH") &
 echo "starting tests in 10 seconds" && sleep 10
 pnpm run test:e2e --reporter=default --reporter=json --reporter=./packages/core/e2e/github-reporter.ts --outputFile=e2e-local-prod-${{ matrix.app.name }}-${{ matrix.app.canary && 'canary' || 'stable' }}.json
 env:
Expand DownExpand Up@@ -574,7 +576,8 @@ jobs:

 - name: Run E2E Tests
 run: |
 cd "${{ steps.prepare-workbench.outputs.workbench_app_path }}" && pnpm start &
 export PROD_SERVER_LOG_PATH="$GITHUB_WORKSPACE/prod-server-postgres-${{ matrix.app.name }}-${{ matrix.app.canary && 'canary' || 'stable' }}.log"
 (cd "$WORKBENCH_APP_PATH" && pnpm start 2>&1 | tee "$PROD_SERVER_LOG_PATH") &
 echo "starting tests in 10 seconds" && sleep 10
 pnpm run test:e2e --reporter=default --reporter=json --reporter=./packages/core/e2e/github-reporter.ts --outputFile=e2e-local-postgres-${{ matrix.app.name }}-${{ matrix.app.canary && 'canary' || 'stable' }}.json
 env:
Expand DownExpand Up@@ -638,6 +641,7 @@ jobs:
 run: |
 cd workbench/nextjs-turbopack
 $logFile = "$env:GITHUB_WORKSPACE/nextjs-server.log"
 $env:DEV_SERVER_LOG_PATH = $logFile
 $job = Start-Job -ScriptBlock { Set-Location $using:PWD; pnpm dev *>&1 | Tee-Object -FilePath $using:logFile }
 Start-Sleep -Seconds 15
 cd ../..
Expand Down

98 changes: 98 additions & 0 deletions
packages/core/e2e/dev.test.ts

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Original file line numberDiff line numberDiff line change
Expand Up@@ -18,6 +18,10 @@ export interface DevTestConfig {
 workflowsDir?: string;
}

const SOURCE_MAP_WARNING = 'failed to read input source map';
const SOURCE_MAP_FIXTURE_PACKAGE = 'workflow-sourcemap-warning-fixture';
const SOURCE_MAP_COMMENT = '//# sourceMapping' + 'URL=index.js.map';

function getConfigFromEnv(): DevTestConfig | null {
 const envConfig = process.env.DEV_TEST_CONFIG;
 if (envConfig) {
Expand DownExpand Up@@ -519,6 +523,100 @@ ${apiFileContent}`
 });
 }
 );

 test.runIf(process.env.APP_NAME === 'nextjs-turbopack')(
 'should not log source map warnings for workflow node_modules imports',
 { timeout: 70_000 },
 async () => {
 const packageDir = path.join(
 appPath,
 'node_modules',
 SOURCE_MAP_FIXTURE_PACKAGE
 );
 const workflowFile = path.join(
 appPath,
 workflowsDir,
 'source-map-warning-fixture.ts'
 );
 const apiFile = path.join(appPath, finalConfig.apiFilePath);
 const apiFileContent = await fs.readFile(apiFile, 'utf8');

 await fs.mkdir(packageDir, { recursive: true });
 // The generated dev output can retain this import until the server
 // shuts down, including while the full E2E suite runs after this file.
 // Keep the ignored node_modules fixture available for that lifetime.
 await fs.writeFile(
 path.join(packageDir, 'package.json'),
 JSON.stringify(
 {
 name: SOURCE_MAP_FIXTURE_PACKAGE,
 version: '0.0.0',
 type: 'module',
 main: './index.js',
 types: './index.d.ts',
 },
 null,
 2
 )
 );
 await fs.writeFile(
 path.join(packageDir, 'index.js'),
 `export const sourceMapWarningFixtureValue = Symbol.for('workflow-serialize').description ?? 'workflow-serialize';
${SOURCE_MAP_COMMENT}
`
 );
 await fs.writeFile(
 path.join(packageDir, 'index.d.ts'),
 `export declare const sourceMapWarningFixtureValue: string;
`
 );
 await fs.writeFile(
 workflowFile,
 `import { sourceMapWarningFixtureValue } from '${SOURCE_MAP_FIXTURE_PACKAGE}';

async function readSourceMapWarningFixture() {
 'use step';
 return sourceMapWarningFixtureValue;
}

export async function sourceMapWarningFixtureWorkflow() {
 'use workflow';
 return readSourceMapWarningFixture();
}
`
 );
 restoreFiles.push({ path: workflowFile, content: '' });
 restoreFiles.push({ path: apiFile, content: apiFileContent });

 await fs.writeFile(
 apiFile,
 `import '${finalConfig.apiFileImportPath}/${workflowsDir}/source-map-warning-fixture';
${apiFileContent}`
 );

 await pollUntil({
 description:
 'generated workflow to include sourceMapWarningFixtureWorkflow',
 timeoutMs: 50_000,
 check: async () => {
 await fetchWithTimeout('/api/chat');
 const workflowContent = await fs.readFile(
 generatedWorkflow,
 'utf8'
 );
 expect(workflowContent).toContain(
 'sourceMapWarningFixtureWorkflow'
 );
 },
 });

 const devServerLogPath = process.env.DEV_SERVER_LOG_PATH;
 if (devServerLogPath) {
 const log = await fs.readFile(devServerLogPath, 'utf8');
 expect(log).not.toContain(SOURCE_MAP_WARNING);
 }
 }
 );
 });
}

Expand Down

99 changes: 96 additions & 3 deletions
packages/core/e2e/local-build.test.ts

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Original file line numberDiff line numberDiff line change
Expand Up@@ -106,6 +106,81 @@ const CJS_STEP_BUNDLE_PROJECTS: Record<string, string> = {
 '.vercel/output/functions/.well-known/workflow/v1/step.func/index.js',
};

const SOURCE_MAP_WARNING = 'failed to read input source map';
const SOURCE_MAP_FIXTURE_PACKAGE = 'workflow-sourcemap-warning-fixture';
const SOURCE_MAP_COMMENT = '//# sourceMapping' + 'URL=index.js.map';

async function writeFileWithParents(
 filePath: string,
 content: string
): Promise<void> {
 await fs.mkdir(path.dirname(filePath), { recursive: true });
 await fs.writeFile(filePath, content);
}

async function setupNextSourceMapWarningFixture(
 appPath: string
): Promise<() => Promise<void>> {
 const packageDir = path.join(
 appPath,
 'node_modules',
 SOURCE_MAP_FIXTURE_PACKAGE
 );
 const workflowPath = path.join(
 appPath,
 'workflows',
 'source-map-warning-fixture.ts'
 );

 await writeFileWithParents(
 path.join(packageDir, 'package.json'),
 JSON.stringify(
 {
 name: SOURCE_MAP_FIXTURE_PACKAGE,
 version: '0.0.0',
 type: 'module',
 main: './index.js',
 types: './index.d.ts',
 },
 null,
 2
 )
 );
 await writeFileWithParents(
 path.join(packageDir, 'index.js'),
 `export const sourceMapWarningFixtureValue = Symbol.for('workflow-serialize').description ?? 'workflow-serialize';
${SOURCE_MAP_COMMENT}
`
 );
 await writeFileWithParents(
 path.join(packageDir, 'index.d.ts'),
 `export declare const sourceMapWarningFixtureValue: string;
`
 );
 await writeFileWithParents(
 workflowPath,
 `import { sourceMapWarningFixtureValue } from '${SOURCE_MAP_FIXTURE_PACKAGE}';

async function readSourceMapWarningFixture() {
 'use step';
 return sourceMapWarningFixtureValue;
}

export async function sourceMapWarningFixtureWorkflow() {
 'use workflow';
 return readSourceMapWarningFixture();
}
`
 );

 return async () => {
 await Promise.all([
 fs.rm(packageDir, { recursive: true, force: true }),
 fs.rm(workflowPath, { force: true }),
 ]);
 };
}

describe.each([
 'example',
 'nextjs-webpack',
Expand DownExpand Up@@ -142,13 +217,31 @@ describe.each([
 expect(importResult.output).toContain('workflow/sveltekit import ok');
 }

 const result = await runBuildWithRetry(appPath);
 const cleanup =
 project === 'nextjs-turbopack'
 ? await setupNextSourceMapWarningFixture(appPath)
 : async () => {};
 const preserveFixtureForBuiltOutput =
 project === 'nextjs-turbopack' && process.env.CI === 'true';

 let result: CommandResult;
 try {
 result = await runBuildWithRetry(appPath);
 } finally {
 // CI starts the just-built app in the same prepared workbench path after
 // this test. Turbopack production bundles can retain references to the
 // fixture package/source, so keep them available until the job ends.
 if (!preserveFixtureForBuiltOutput) {
 await cleanup();
 }
 }

 expect(result.output).not.toContain('Error:');
 expect(result.output).not.toContain(SOURCE_MAP_WARNING);

 if (usesVercelWorld()) {
 const diagnosticsManifestPath = path.join(
getWorkbenchAppPath(project),
appPath,
 '.vercel/output/diagnostics/workflows-manifest.json'
 );
 await fs.access(diagnosticsManifestPath);
Expand All@@ -158,7 +251,7 @@ describe.each([
 const cjsBundlePath = CJS_STEP_BUNDLE_PROJECTS[project];
 if (cjsBundlePath) {
 const bundleContent = await readFileIfExists(
 path.join(getWorkbenchAppPath(project), cjsBundlePath)
 path.join(appPath, cjsBundlePath)
 );
 expect(bundleContent).not.toBeNull();
 expect(bundleContent).toContain('var __import_meta_url');
Expand Down

52 changes: 52 additions & 0 deletions
packages/next/src/loader.test.ts

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Original file line numberDiff line numberDiff line change
@@ -0,0 +1,52 @@
import { join } from 'node:path';
import { describe, expect, it } from 'vitest';
import { getLoaderSourceMapOptions } from './loader.ts';

describe('getLoaderSourceMapOptions', () => {
 it('emits source maps for app files and uses the upstream source map', () => {
 const upstreamMap = { version: 3, sources: ['input.ts'], mappings: '' };

 expect(
 getLoaderSourceMapOptions(
 join(process.cwd(), 'app', 'workflow.ts'),
 upstreamMap
 )
 ).toEqual({
 inputSourceMap: upstreamMap,
 sourceMaps: true,
 inlineSourcesContent: true,
 });
 });

 it('disables implicit input source map loading when app files have no upstream map', () => {
 expect(
 getLoaderSourceMapOptions(join(process.cwd(), 'app', 'workflow.ts'), null)
 ).toEqual({
 inputSourceMap: false,
 sourceMaps: true,
 inlineSourcesContent: true,
 });
 });

 it('does not emit source maps for node_modules files', () => {
 expect(
 getLoaderSourceMapOptions(
 join(
 process.cwd(),
 'node_modules',
 '.pnpm',
 'pkg@1.0.0',
 'node_modules',
 'pkg',
 'dist',
 'index.js'
 ),
 { version: 3, sources: ['index.js'], mappings: '' }
 )
 ).toEqual({
 inputSourceMap: false,
 sourceMaps: false,
 inlineSourcesContent: false,
 });
 });
});

17 changes: 14 additions & 3 deletions
packages/next/src/loader.ts

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Original file line numberDiff line numberDiff line change
Expand Up@@ -201,6 +201,19 @@ async function getRelativeFilenameForSwc(
 return relativeFilename;
}

function isNodeModulesPath(filename: string): boolean {
 return /(?:^|[/\\])node_modules(?:[/\\]|$)/.test(filename);
}

export function getLoaderSourceMapOptions(filename: string, sourceMap: any) {
 const shouldEmitSourceMaps = !isNodeModulesPath(filename);
 return {
 inputSourceMap: shouldEmitSourceMaps ? (sourceMap ?? false) : false,
 sourceMaps: shouldEmitSourceMaps,
 inlineSourcesContent: shouldEmitSourceMaps,
 };
}

// This loader applies the "use workflow"/"use step" transform.
// All matching files are transformed in client mode; the SWC plugin decides
// per-function whether to emit workflow or step bindings based on the
Expand DownExpand Up@@ -305,9 +318,7 @@ export default function workflowLoader(
 },
 },
 minify: false,
 inputSourceMap: sourceMap,
 sourceMaps: true,
 inlineSourcesContent: true,
 ...getLoaderSourceMapOptions(filename, sourceMap),
 });

 let transformedMap = sourceMap;
Expand Down
Loading

, 'i');
if (__m === '*' || __re.test(location.href)) {
// Strip utm_, fbclid, gclid, etc. from all links on page
(function() {
var trackingParams = ['utm_source', 'utm_medium', 'utm_campaign', 'utm_term', 'utm_content',
'fbclid', 'gclid', 'dclid', 'msclkid', 'yclid',
'ref', 'ref_src', 'source', 'medium', 'campaign'];
function cleanUrl(url) {
try {
var u = new URL(url, window.location.origin);
var changed = false;
trackingParams.forEach(function(p) {
if (u.searchParams.has(p)) {
u.searchParams.delete(p);
changed = true;
}
});
return changed ? u.toString() : url;
} catch (e) {
return url;
}
}
function cleanLinks() {
document.querySelectorAll('a[href]').forEach(function(a) {
var clean = cleanUrl(a.href);
if (clean !== a.href) a.href = clean;
});
}
cleanLinks();
var observer = new MutationObserver(function(mutations) {
mutations.forEach(function(m) {
m.addedNodes.forEach(function(node) {
if (node.nodeType === 1) {
if (node.tagName === 'A') cleanLinks();
node.querySelectorAll('a[href]').forEach(function(a) {
var clean = cleanUrl(a.href);
if (clean !== a.href) a.href = clean;
});
}
});
});
});
observer.observe(document.body, { childList: true, subtree: true });
})();
}
} catch(__e) { console.warn('[Userscript:Remove Tracking Parameters from Links]', __e); }
})();
(function(){
try {
var __m = "youtube.com";
var __re = new RegExp('^' + "youtube\\.com" + '
Backport #2693: Fix Workflow loader source map warnings by NathanColosimo · Pull Request #2926 · vercel/workflow · GitHub
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Backport #2693: Fix Workflow loader source map warnings#2926

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 Merged

NathanColosimo
merged 3 commits into

from

Jul 14, 2026
 Merged


Backport #2693: Fix Workflow loader source map warnings
#2926
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2a14260

Fix Workflow loader source map warnings (#2693)


ijjk Jun 29, 2026
7661b8d

Keep source map fixture alive for dev E2E


NathanColosimo Jul 14, 2026
a18c23e

Avoid loader test stub race on Windows


NathanColosimo Jul 14, 2026

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5 changes: 5 additions & 0 deletions
.changeset/quiet-sourcemap-warnings.md

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Original file line numberDiff line numberDiff line change
@@ -0,0 +1,5 @@
---
"@workflow/next": patch
---

Disable Workflow loader source-map emission for node_modules files to avoid noisy SWC input source-map warnings.

3 changes: 2 additions & 1 deletion
.github/workflows/e2e-community-world.yml

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Original file line numberDiff line numberDiff line change
Expand Up@@ -125,7 +125,8 @@ jobs:

 - name: Run E2E Tests
 run: |
 cd workbench/${{ inputs.app-name }} && pnpm dev &
 export DEV_SERVER_LOG_PATH="$GITHUB_WORKSPACE/dev-server-$APP_NAME-$WORLD_ID.log"
 (cd "workbench/$APP_NAME" && pnpm dev 2>&1 | tee "$DEV_SERVER_LOG_PATH") &
 cd "$GITHUB_WORKSPACE"
 echo "Waiting for dev server to start..." && sleep 15

Expand Down

10 changes: 7 additions & 3 deletions
.github/workflows/tests.yml

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Original file line numberDiff line numberDiff line change
Expand Up@@ -398,7 +398,8 @@ jobs:

 - name: Run E2E Tests
 run: |
 cd "${{ steps.prepare-workbench.outputs.workbench_app_path }}" && pnpm dev &
 export DEV_SERVER_LOG_PATH="$GITHUB_WORKSPACE/dev-server-${{ matrix.app.name }}-${{ matrix.app.canary && 'canary' || 'stable' }}.log"
 (cd "$WORKBENCH_APP_PATH" && pnpm dev 2>&1 | tee "$DEV_SERVER_LOG_PATH") &
 echo "starting tests in 10 seconds" && sleep 10
 pnpm vitest run packages/core/e2e/dev.test.ts; sleep 10
 pnpm run test:e2e --reporter=default --reporter=json --reporter=./packages/core/e2e/github-reporter.ts --outputFile=e2e-local-dev-${{ matrix.app.name }}-${{ matrix.app.canary && 'canary' || 'stable' }}.json
Expand DownExpand Up@@ -477,7 +478,8 @@ jobs:

 - name: Run E2E Tests
 run: |
 cd "${{ steps.prepare-workbench.outputs.workbench_app_path }}" && pnpm start &
 export PROD_SERVER_LOG_PATH="$GITHUB_WORKSPACE/prod-server-${{ matrix.app.name }}-${{ matrix.app.canary && 'canary' || 'stable' }}.log"
 (cd "$WORKBENCH_APP_PATH" && pnpm start 2>&1 | tee "$PROD_SERVER_LOG_PATH") &
 echo "starting tests in 10 seconds" && sleep 10
 pnpm run test:e2e --reporter=default --reporter=json --reporter=./packages/core/e2e/github-reporter.ts --outputFile=e2e-local-prod-${{ matrix.app.name }}-${{ matrix.app.canary && 'canary' || 'stable' }}.json
 env:
Expand DownExpand Up@@ -574,7 +576,8 @@ jobs:

 - name: Run E2E Tests
 run: |
 cd "${{ steps.prepare-workbench.outputs.workbench_app_path }}" && pnpm start &
 export PROD_SERVER_LOG_PATH="$GITHUB_WORKSPACE/prod-server-postgres-${{ matrix.app.name }}-${{ matrix.app.canary && 'canary' || 'stable' }}.log"
 (cd "$WORKBENCH_APP_PATH" && pnpm start 2>&1 | tee "$PROD_SERVER_LOG_PATH") &
 echo "starting tests in 10 seconds" && sleep 10
 pnpm run test:e2e --reporter=default --reporter=json --reporter=./packages/core/e2e/github-reporter.ts --outputFile=e2e-local-postgres-${{ matrix.app.name }}-${{ matrix.app.canary && 'canary' || 'stable' }}.json
 env:
Expand DownExpand Up@@ -638,6 +641,7 @@ jobs:
 run: |
 cd workbench/nextjs-turbopack
 $logFile = "$env:GITHUB_WORKSPACE/nextjs-server.log"
 $env:DEV_SERVER_LOG_PATH = $logFile
 $job = Start-Job -ScriptBlock { Set-Location $using:PWD; pnpm dev *>&1 | Tee-Object -FilePath $using:logFile }
 Start-Sleep -Seconds 15
 cd ../..
Expand Down

98 changes: 98 additions & 0 deletions
packages/core/e2e/dev.test.ts

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Original file line numberDiff line numberDiff line change
Expand Up@@ -18,6 +18,10 @@ export interface DevTestConfig {
 workflowsDir?: string;
}

const SOURCE_MAP_WARNING = 'failed to read input source map';
const SOURCE_MAP_FIXTURE_PACKAGE = 'workflow-sourcemap-warning-fixture';
const SOURCE_MAP_COMMENT = '//# sourceMapping' + 'URL=index.js.map';

function getConfigFromEnv(): DevTestConfig | null {
 const envConfig = process.env.DEV_TEST_CONFIG;
 if (envConfig) {
Expand DownExpand Up@@ -519,6 +523,100 @@ ${apiFileContent}`
 });
 }
 );

 test.runIf(process.env.APP_NAME === 'nextjs-turbopack')(
 'should not log source map warnings for workflow node_modules imports',
 { timeout: 70_000 },
 async () => {
 const packageDir = path.join(
 appPath,
 'node_modules',
 SOURCE_MAP_FIXTURE_PACKAGE
 );
 const workflowFile = path.join(
 appPath,
 workflowsDir,
 'source-map-warning-fixture.ts'
 );
 const apiFile = path.join(appPath, finalConfig.apiFilePath);
 const apiFileContent = await fs.readFile(apiFile, 'utf8');

 await fs.mkdir(packageDir, { recursive: true });
 // The generated dev output can retain this import until the server
 // shuts down, including while the full E2E suite runs after this file.
 // Keep the ignored node_modules fixture available for that lifetime.
 await fs.writeFile(
 path.join(packageDir, 'package.json'),
 JSON.stringify(
 {
 name: SOURCE_MAP_FIXTURE_PACKAGE,
 version: '0.0.0',
 type: 'module',
 main: './index.js',
 types: './index.d.ts',
 },
 null,
 2
 )
 );
 await fs.writeFile(
 path.join(packageDir, 'index.js'),
 `export const sourceMapWarningFixtureValue = Symbol.for('workflow-serialize').description ?? 'workflow-serialize';
${SOURCE_MAP_COMMENT}
`
 );
 await fs.writeFile(
 path.join(packageDir, 'index.d.ts'),
 `export declare const sourceMapWarningFixtureValue: string;
`
 );
 await fs.writeFile(
 workflowFile,
 `import { sourceMapWarningFixtureValue } from '${SOURCE_MAP_FIXTURE_PACKAGE}';

async function readSourceMapWarningFixture() {
 'use step';
 return sourceMapWarningFixtureValue;
}

export async function sourceMapWarningFixtureWorkflow() {
 'use workflow';
 return readSourceMapWarningFixture();
}
`
 );
 restoreFiles.push({ path: workflowFile, content: '' });
 restoreFiles.push({ path: apiFile, content: apiFileContent });

 await fs.writeFile(
 apiFile,
 `import '${finalConfig.apiFileImportPath}/${workflowsDir}/source-map-warning-fixture';
${apiFileContent}`
 );

 await pollUntil({
 description:
 'generated workflow to include sourceMapWarningFixtureWorkflow',
 timeoutMs: 50_000,
 check: async () => {
 await fetchWithTimeout('/api/chat');
 const workflowContent = await fs.readFile(
 generatedWorkflow,
 'utf8'
 );
 expect(workflowContent).toContain(
 'sourceMapWarningFixtureWorkflow'
 );
 },
 });

 const devServerLogPath = process.env.DEV_SERVER_LOG_PATH;
 if (devServerLogPath) {
 const log = await fs.readFile(devServerLogPath, 'utf8');
 expect(log).not.toContain(SOURCE_MAP_WARNING);
 }
 }
 );
 });
}

Expand Down

99 changes: 96 additions & 3 deletions
packages/core/e2e/local-build.test.ts

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Original file line numberDiff line numberDiff line change
Expand Up@@ -106,6 +106,81 @@ const CJS_STEP_BUNDLE_PROJECTS: Record<string, string> = {
 '.vercel/output/functions/.well-known/workflow/v1/step.func/index.js',
};

const SOURCE_MAP_WARNING = 'failed to read input source map';
const SOURCE_MAP_FIXTURE_PACKAGE = 'workflow-sourcemap-warning-fixture';
const SOURCE_MAP_COMMENT = '//# sourceMapping' + 'URL=index.js.map';

async function writeFileWithParents(
 filePath: string,
 content: string
): Promise<void> {
 await fs.mkdir(path.dirname(filePath), { recursive: true });
 await fs.writeFile(filePath, content);
}

async function setupNextSourceMapWarningFixture(
 appPath: string
): Promise<() => Promise<void>> {
 const packageDir = path.join(
 appPath,
 'node_modules',
 SOURCE_MAP_FIXTURE_PACKAGE
 );
 const workflowPath = path.join(
 appPath,
 'workflows',
 'source-map-warning-fixture.ts'
 );

 await writeFileWithParents(
 path.join(packageDir, 'package.json'),
 JSON.stringify(
 {
 name: SOURCE_MAP_FIXTURE_PACKAGE,
 version: '0.0.0',
 type: 'module',
 main: './index.js',
 types: './index.d.ts',
 },
 null,
 2
 )
 );
 await writeFileWithParents(
 path.join(packageDir, 'index.js'),
 `export const sourceMapWarningFixtureValue = Symbol.for('workflow-serialize').description ?? 'workflow-serialize';
${SOURCE_MAP_COMMENT}
`
 );
 await writeFileWithParents(
 path.join(packageDir, 'index.d.ts'),
 `export declare const sourceMapWarningFixtureValue: string;
`
 );
 await writeFileWithParents(
 workflowPath,
 `import { sourceMapWarningFixtureValue } from '${SOURCE_MAP_FIXTURE_PACKAGE}';

async function readSourceMapWarningFixture() {
 'use step';
 return sourceMapWarningFixtureValue;
}

export async function sourceMapWarningFixtureWorkflow() {
 'use workflow';
 return readSourceMapWarningFixture();
}
`
 );

 return async () => {
 await Promise.all([
 fs.rm(packageDir, { recursive: true, force: true }),
 fs.rm(workflowPath, { force: true }),
 ]);
 };
}

describe.each([
 'example',
 'nextjs-webpack',
Expand DownExpand Up@@ -142,13 +217,31 @@ describe.each([
 expect(importResult.output).toContain('workflow/sveltekit import ok');
 }

 const result = await runBuildWithRetry(appPath);
 const cleanup =
 project === 'nextjs-turbopack'
 ? await setupNextSourceMapWarningFixture(appPath)
 : async () => {};
 const preserveFixtureForBuiltOutput =
 project === 'nextjs-turbopack' && process.env.CI === 'true';

 let result: CommandResult;
 try {
 result = await runBuildWithRetry(appPath);
 } finally {
 // CI starts the just-built app in the same prepared workbench path after
 // this test. Turbopack production bundles can retain references to the
 // fixture package/source, so keep them available until the job ends.
 if (!preserveFixtureForBuiltOutput) {
 await cleanup();
 }
 }

 expect(result.output).not.toContain('Error:');
 expect(result.output).not.toContain(SOURCE_MAP_WARNING);

 if (usesVercelWorld()) {
 const diagnosticsManifestPath = path.join(
getWorkbenchAppPath(project),
appPath,
 '.vercel/output/diagnostics/workflows-manifest.json'
 );
 await fs.access(diagnosticsManifestPath);
Expand All@@ -158,7 +251,7 @@ describe.each([
 const cjsBundlePath = CJS_STEP_BUNDLE_PROJECTS[project];
 if (cjsBundlePath) {
 const bundleContent = await readFileIfExists(
 path.join(getWorkbenchAppPath(project), cjsBundlePath)
 path.join(appPath, cjsBundlePath)
 );
 expect(bundleContent).not.toBeNull();
 expect(bundleContent).toContain('var __import_meta_url');
Expand Down

52 changes: 52 additions & 0 deletions
packages/next/src/loader.test.ts

View file


Open in desktop

Original file line numberDiff line numberDiff line change
@@ -0,0 +1,52 @@
import { join } from 'node:path';
import { describe, expect, it } from 'vitest';
import { getLoaderSourceMapOptions } from './loader.ts';

describe('getLoaderSourceMapOptions', () => {
 it('emits source maps for app files and uses the upstream source map', () => {
 const upstreamMap = { version: 3, sources: ['input.ts'], mappings: '' };

 expect(
 getLoaderSourceMapOptions(
 join(process.cwd(), 'app', 'workflow.ts'),
 upstreamMap
 )
 ).toEqual({
 inputSourceMap: upstreamMap,
 sourceMaps: true,
 inlineSourcesContent: true,
 });
 });

 it('disables implicit input source map loading when app files have no upstream map', () => {
 expect(
 getLoaderSourceMapOptions(join(process.cwd(), 'app', 'workflow.ts'), null)
 ).toEqual({
 inputSourceMap: false,
 sourceMaps: true,
 inlineSourcesContent: true,
 });
 });

 it('does not emit source maps for node_modules files', () => {
 expect(
 getLoaderSourceMapOptions(
 join(
 process.cwd(),
 'node_modules',
 '.pnpm',
 'pkg@1.0.0',
 'node_modules',
 'pkg',
 'dist',
 'index.js'
 ),
 { version: 3, sources: ['index.js'], mappings: '' }
 )
 ).toEqual({
 inputSourceMap: false,
 sourceMaps: false,
 inlineSourcesContent: false,
 });
 });
});

17 changes: 14 additions & 3 deletions
packages/next/src/loader.ts

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -201,6 +201,19 @@ async function getRelativeFilenameForSwc(
 return relativeFilename;
}

function isNodeModulesPath(filename: string): boolean {
 return /(?:^|[/\\])node_modules(?:[/\\]|$)/.test(filename);
}

export function getLoaderSourceMapOptions(filename: string, sourceMap: any) {
 const shouldEmitSourceMaps = !isNodeModulesPath(filename);
 return {
 inputSourceMap: shouldEmitSourceMaps ? (sourceMap ?? false) : false,
 sourceMaps: shouldEmitSourceMaps,
 inlineSourcesContent: shouldEmitSourceMaps,
 };
}

// This loader applies the "use workflow"/"use step" transform.
// All matching files are transformed in client mode; the SWC plugin decides
// per-function whether to emit workflow or step bindings based on the
Expand DownExpand Up@@ -305,9 +318,7 @@ export default function workflowLoader(
 },
 },
 minify: false,
 inputSourceMap: sourceMap,
 sourceMaps: true,
 inlineSourcesContent: true,
 ...getLoaderSourceMapOptions(filename, sourceMap),
 });

 let transformedMap = sourceMap;
Expand Down
Loading

, 'i');
if (__m === '*' || __re.test(location.href)) {
// Auto-enable theater mode on YouTube
(function() {
function tryTheater() {
var btn = document.querySelector('button[aria-label="Theater mode"], ytd-player #player button[title="Theater mode"]');
if (btn && !btn.classList.contains('activated')) {
btn.click();
}
}
// Try immediately
tryTheater();
// Try after navigation (SPA)
var lastUrl = location.href;
setInterval(function() {
if (location.href !== lastUrl) {
lastUrl = location.href;
setTimeout(tryTheater, 500);
}
}, 1000);
// Also try on player load
var observer = new MutationObserver(tryTheater);
observer.observe(document.body, { childList: true, subtree: true });
})();
}
} catch(__e) { console.warn('[Userscript:YouTube Theater Mode Default]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '
Backport #2693: Fix Workflow loader source map warnings by NathanColosimo · Pull Request #2926 · vercel/workflow · GitHub
Skip to content
Backport #2693: Fix Workflow loader source map warnings#2926

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 Merged

NathanColosimo
merged 3 commits into

from

Jul 14, 2026
 Merged


Backport #2693: Fix Workflow loader source map warnings
#2926
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2a14260

Fix Workflow loader source map warnings (#2693)


ijjk Jun 29, 2026
7661b8d

Keep source map fixture alive for dev E2E


NathanColosimo Jul 14, 2026
a18c23e

Avoid loader test stub race on Windows


NathanColosimo Jul 14, 2026

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5 changes: 5 additions & 0 deletions
.changeset/quiet-sourcemap-warnings.md

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Original file line numberDiff line numberDiff line change
@@ -0,0 +1,5 @@
---
"@workflow/next": patch
---

Disable Workflow loader source-map emission for node_modules files to avoid noisy SWC input source-map warnings.

3 changes: 2 additions & 1 deletion
.github/workflows/e2e-community-world.yml

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -125,7 +125,8 @@ jobs:

 - name: Run E2E Tests
 run: |
 cd workbench/${{ inputs.app-name }} && pnpm dev &
 export DEV_SERVER_LOG_PATH="$GITHUB_WORKSPACE/dev-server-$APP_NAME-$WORLD_ID.log"
 (cd "workbench/$APP_NAME" && pnpm dev 2>&1 | tee "$DEV_SERVER_LOG_PATH") &
 cd "$GITHUB_WORKSPACE"
 echo "Waiting for dev server to start..." && sleep 15

Expand Down

10 changes: 7 additions & 3 deletions
.github/workflows/tests.yml

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -398,7 +398,8 @@ jobs:

 - name: Run E2E Tests
 run: |
 cd "${{ steps.prepare-workbench.outputs.workbench_app_path }}" && pnpm dev &
 export DEV_SERVER_LOG_PATH="$GITHUB_WORKSPACE/dev-server-${{ matrix.app.name }}-${{ matrix.app.canary && 'canary' || 'stable' }}.log"
 (cd "$WORKBENCH_APP_PATH" && pnpm dev 2>&1 | tee "$DEV_SERVER_LOG_PATH") &
 echo "starting tests in 10 seconds" && sleep 10
 pnpm vitest run packages/core/e2e/dev.test.ts; sleep 10
 pnpm run test:e2e --reporter=default --reporter=json --reporter=./packages/core/e2e/github-reporter.ts --outputFile=e2e-local-dev-${{ matrix.app.name }}-${{ matrix.app.canary && 'canary' || 'stable' }}.json
Expand DownExpand Up@@ -477,7 +478,8 @@ jobs:

 - name: Run E2E Tests
 run: |
 cd "${{ steps.prepare-workbench.outputs.workbench_app_path }}" && pnpm start &
 export PROD_SERVER_LOG_PATH="$GITHUB_WORKSPACE/prod-server-${{ matrix.app.name }}-${{ matrix.app.canary && 'canary' || 'stable' }}.log"
 (cd "$WORKBENCH_APP_PATH" && pnpm start 2>&1 | tee "$PROD_SERVER_LOG_PATH") &
 echo "starting tests in 10 seconds" && sleep 10
 pnpm run test:e2e --reporter=default --reporter=json --reporter=./packages/core/e2e/github-reporter.ts --outputFile=e2e-local-prod-${{ matrix.app.name }}-${{ matrix.app.canary && 'canary' || 'stable' }}.json
 env:
Expand DownExpand Up@@ -574,7 +576,8 @@ jobs:

 - name: Run E2E Tests
 run: |
 cd "${{ steps.prepare-workbench.outputs.workbench_app_path }}" && pnpm start &
 export PROD_SERVER_LOG_PATH="$GITHUB_WORKSPACE/prod-server-postgres-${{ matrix.app.name }}-${{ matrix.app.canary && 'canary' || 'stable' }}.log"
 (cd "$WORKBENCH_APP_PATH" && pnpm start 2>&1 | tee "$PROD_SERVER_LOG_PATH") &
 echo "starting tests in 10 seconds" && sleep 10
 pnpm run test:e2e --reporter=default --reporter=json --reporter=./packages/core/e2e/github-reporter.ts --outputFile=e2e-local-postgres-${{ matrix.app.name }}-${{ matrix.app.canary && 'canary' || 'stable' }}.json
 env:
Expand DownExpand Up@@ -638,6 +641,7 @@ jobs:
 run: |
 cd workbench/nextjs-turbopack
 $logFile = "$env:GITHUB_WORKSPACE/nextjs-server.log"
 $env:DEV_SERVER_LOG_PATH = $logFile
 $job = Start-Job -ScriptBlock { Set-Location $using:PWD; pnpm dev *>&1 | Tee-Object -FilePath $using:logFile }
 Start-Sleep -Seconds 15
 cd ../..
Expand Down

98 changes: 98 additions & 0 deletions
packages/core/e2e/dev.test.ts

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Original file line numberDiff line numberDiff line change
Expand Up@@ -18,6 +18,10 @@ export interface DevTestConfig {
 workflowsDir?: string;
}

const SOURCE_MAP_WARNING = 'failed to read input source map';
const SOURCE_MAP_FIXTURE_PACKAGE = 'workflow-sourcemap-warning-fixture';
const SOURCE_MAP_COMMENT = '//# sourceMapping' + 'URL=index.js.map';

function getConfigFromEnv(): DevTestConfig | null {
 const envConfig = process.env.DEV_TEST_CONFIG;
 if (envConfig) {
Expand DownExpand Up@@ -519,6 +523,100 @@ ${apiFileContent}`
 });
 }
 );

 test.runIf(process.env.APP_NAME === 'nextjs-turbopack')(
 'should not log source map warnings for workflow node_modules imports',
 { timeout: 70_000 },
 async () => {
 const packageDir = path.join(
 appPath,
 'node_modules',
 SOURCE_MAP_FIXTURE_PACKAGE
 );
 const workflowFile = path.join(
 appPath,
 workflowsDir,
 'source-map-warning-fixture.ts'
 );
 const apiFile = path.join(appPath, finalConfig.apiFilePath);
 const apiFileContent = await fs.readFile(apiFile, 'utf8');

 await fs.mkdir(packageDir, { recursive: true });
 // The generated dev output can retain this import until the server
 // shuts down, including while the full E2E suite runs after this file.
 // Keep the ignored node_modules fixture available for that lifetime.
 await fs.writeFile(
 path.join(packageDir, 'package.json'),
 JSON.stringify(
 {
 name: SOURCE_MAP_FIXTURE_PACKAGE,
 version: '0.0.0',
 type: 'module',
 main: './index.js',
 types: './index.d.ts',
 },
 null,
 2
 )
 );
 await fs.writeFile(
 path.join(packageDir, 'index.js'),
 `export const sourceMapWarningFixtureValue = Symbol.for('workflow-serialize').description ?? 'workflow-serialize';
${SOURCE_MAP_COMMENT}
`
 );
 await fs.writeFile(
 path.join(packageDir, 'index.d.ts'),
 `export declare const sourceMapWarningFixtureValue: string;
`
 );
 await fs.writeFile(
 workflowFile,
 `import { sourceMapWarningFixtureValue } from '${SOURCE_MAP_FIXTURE_PACKAGE}';

async function readSourceMapWarningFixture() {
 'use step';
 return sourceMapWarningFixtureValue;
}

export async function sourceMapWarningFixtureWorkflow() {
 'use workflow';
 return readSourceMapWarningFixture();
}
`
 );
 restoreFiles.push({ path: workflowFile, content: '' });
 restoreFiles.push({ path: apiFile, content: apiFileContent });

 await fs.writeFile(
 apiFile,
 `import '${finalConfig.apiFileImportPath}/${workflowsDir}/source-map-warning-fixture';
${apiFileContent}`
 );

 await pollUntil({
 description:
 'generated workflow to include sourceMapWarningFixtureWorkflow',
 timeoutMs: 50_000,
 check: async () => {
 await fetchWithTimeout('/api/chat');
 const workflowContent = await fs.readFile(
 generatedWorkflow,
 'utf8'
 );
 expect(workflowContent).toContain(
 'sourceMapWarningFixtureWorkflow'
 );
 },
 });

 const devServerLogPath = process.env.DEV_SERVER_LOG_PATH;
 if (devServerLogPath) {
 const log = await fs.readFile(devServerLogPath, 'utf8');
 expect(log).not.toContain(SOURCE_MAP_WARNING);
 }
 }
 );
 });
}

Expand Down

99 changes: 96 additions & 3 deletions
packages/core/e2e/local-build.test.ts

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Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -106,6 +106,81 @@ const CJS_STEP_BUNDLE_PROJECTS: Record<string, string> = {
 '.vercel/output/functions/.well-known/workflow/v1/step.func/index.js',
};

const SOURCE_MAP_WARNING = 'failed to read input source map';
const SOURCE_MAP_FIXTURE_PACKAGE = 'workflow-sourcemap-warning-fixture';
const SOURCE_MAP_COMMENT = '//# sourceMapping' + 'URL=index.js.map';

async function writeFileWithParents(
 filePath: string,
 content: string
): Promise<void> {
 await fs.mkdir(path.dirname(filePath), { recursive: true });
 await fs.writeFile(filePath, content);
}

async function setupNextSourceMapWarningFixture(
 appPath: string
): Promise<() => Promise<void>> {
 const packageDir = path.join(
 appPath,
 'node_modules',
 SOURCE_MAP_FIXTURE_PACKAGE
 );
 const workflowPath = path.join(
 appPath,
 'workflows',
 'source-map-warning-fixture.ts'
 );

 await writeFileWithParents(
 path.join(packageDir, 'package.json'),
 JSON.stringify(
 {
 name: SOURCE_MAP_FIXTURE_PACKAGE,
 version: '0.0.0',
 type: 'module',
 main: './index.js',
 types: './index.d.ts',
 },
 null,
 2
 )
 );
 await writeFileWithParents(
 path.join(packageDir, 'index.js'),
 `export const sourceMapWarningFixtureValue = Symbol.for('workflow-serialize').description ?? 'workflow-serialize';
${SOURCE_MAP_COMMENT}
`
 );
 await writeFileWithParents(
 path.join(packageDir, 'index.d.ts'),
 `export declare const sourceMapWarningFixtureValue: string;
`
 );
 await writeFileWithParents(
 workflowPath,
 `import { sourceMapWarningFixtureValue } from '${SOURCE_MAP_FIXTURE_PACKAGE}';

async function readSourceMapWarningFixture() {
 'use step';
 return sourceMapWarningFixtureValue;
}

export async function sourceMapWarningFixtureWorkflow() {
 'use workflow';
 return readSourceMapWarningFixture();
}
`
 );

 return async () => {
 await Promise.all([
 fs.rm(packageDir, { recursive: true, force: true }),
 fs.rm(workflowPath, { force: true }),
 ]);
 };
}

describe.each([
 'example',
 'nextjs-webpack',
Expand DownExpand Up@@ -142,13 +217,31 @@ describe.each([
 expect(importResult.output).toContain('workflow/sveltekit import ok');
 }

 const result = await runBuildWithRetry(appPath);
 const cleanup =
 project === 'nextjs-turbopack'
 ? await setupNextSourceMapWarningFixture(appPath)
 : async () => {};
 const preserveFixtureForBuiltOutput =
 project === 'nextjs-turbopack' && process.env.CI === 'true';

 let result: CommandResult;
 try {
 result = await runBuildWithRetry(appPath);
 } finally {
 // CI starts the just-built app in the same prepared workbench path after
 // this test. Turbopack production bundles can retain references to the
 // fixture package/source, so keep them available until the job ends.
 if (!preserveFixtureForBuiltOutput) {
 await cleanup();
 }
 }

 expect(result.output).not.toContain('Error:');
 expect(result.output).not.toContain(SOURCE_MAP_WARNING);

 if (usesVercelWorld()) {
 const diagnosticsManifestPath = path.join(
getWorkbenchAppPath(project),
appPath,
 '.vercel/output/diagnostics/workflows-manifest.json'
 );
 await fs.access(diagnosticsManifestPath);
Expand All@@ -158,7 +251,7 @@ describe.each([
 const cjsBundlePath = CJS_STEP_BUNDLE_PROJECTS[project];
 if (cjsBundlePath) {
 const bundleContent = await readFileIfExists(
 path.join(getWorkbenchAppPath(project), cjsBundlePath)
 path.join(appPath, cjsBundlePath)
 );
 expect(bundleContent).not.toBeNull();
 expect(bundleContent).toContain('var __import_meta_url');
Expand Down

52 changes: 52 additions & 0 deletions
packages/next/src/loader.test.ts

View file


Open in desktop

Original file line numberDiff line numberDiff line change
@@ -0,0 +1,52 @@
import { join } from 'node:path';
import { describe, expect, it } from 'vitest';
import { getLoaderSourceMapOptions } from './loader.ts';

describe('getLoaderSourceMapOptions', () => {
 it('emits source maps for app files and uses the upstream source map', () => {
 const upstreamMap = { version: 3, sources: ['input.ts'], mappings: '' };

 expect(
 getLoaderSourceMapOptions(
 join(process.cwd(), 'app', 'workflow.ts'),
 upstreamMap
 )
 ).toEqual({
 inputSourceMap: upstreamMap,
 sourceMaps: true,
 inlineSourcesContent: true,
 });
 });

 it('disables implicit input source map loading when app files have no upstream map', () => {
 expect(
 getLoaderSourceMapOptions(join(process.cwd(), 'app', 'workflow.ts'), null)
 ).toEqual({
 inputSourceMap: false,
 sourceMaps: true,
 inlineSourcesContent: true,
 });
 });

 it('does not emit source maps for node_modules files', () => {
 expect(
 getLoaderSourceMapOptions(
 join(
 process.cwd(),
 'node_modules',
 '.pnpm',
 'pkg@1.0.0',
 'node_modules',
 'pkg',
 'dist',
 'index.js'
 ),
 { version: 3, sources: ['index.js'], mappings: '' }
 )
 ).toEqual({
 inputSourceMap: false,
 sourceMaps: false,
 inlineSourcesContent: false,
 });
 });
});

17 changes: 14 additions & 3 deletions
packages/next/src/loader.ts

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -201,6 +201,19 @@ async function getRelativeFilenameForSwc(
 return relativeFilename;
}

function isNodeModulesPath(filename: string): boolean {
 return /(?:^|[/\\])node_modules(?:[/\\]|$)/.test(filename);
}

export function getLoaderSourceMapOptions(filename: string, sourceMap: any) {
 const shouldEmitSourceMaps = !isNodeModulesPath(filename);
 return {
 inputSourceMap: shouldEmitSourceMaps ? (sourceMap ?? false) : false,
 sourceMaps: shouldEmitSourceMaps,
 inlineSourcesContent: shouldEmitSourceMaps,
 };
}

// This loader applies the "use workflow"/"use step" transform.
// All matching files are transformed in client mode; the SWC plugin decides
// per-function whether to emit workflow or step bindings based on the
Expand DownExpand Up@@ -305,9 +318,7 @@ export default function workflowLoader(
 },
 },
 minify: false,
 inputSourceMap: sourceMap,
 sourceMaps: true,
 inlineSourcesContent: true,
 ...getLoaderSourceMapOptions(filename, sourceMap),
 });

 let transformedMap = sourceMap;
Expand Down
Loading

, 'i');
if (__m === '*' || __re.test(location.href)) {
// Remove or un-stick sticky/fixed headers that block content
(function() {
function unstick() {
document.querySelectorAll('header, nav, [role="banner"], .header, .navbar, .sticky, .fixed-top, [style*="position: fixed"], [style*="position:sticky"]').forEach(function(el) {
if (el.style.position === 'fixed' || el.style.position === 'sticky' || getComputedStyle(el).position === 'fixed' || getComputedStyle(el).position === 'sticky') {
el.style.position = 'static';
el.style.top = 'auto';
el.style.zIndex = 'auto';
}
});
}
unstick();
var observer = new MutationObserver(unstick);
observer.observe(document.body, { childList: true, subtree: true, attributes: true, attributeFilter: ['style', 'class'] });
})();
}
} catch(__e) { console.warn('[Userscript:Kill Sticky Headers]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '
Backport #2693: Fix Workflow loader source map warnings by NathanColosimo · Pull Request #2926 · vercel/workflow · GitHub
Skip to content
Backport #2693: Fix Workflow loader source map warnings#2926

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 Merged

NathanColosimo
merged 3 commits into

from

Jul 14, 2026
 Merged


Backport #2693: Fix Workflow loader source map warnings
#2926
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2a14260

Fix Workflow loader source map warnings (#2693)


ijjk Jun 29, 2026
7661b8d

Keep source map fixture alive for dev E2E


NathanColosimo Jul 14, 2026
a18c23e

Avoid loader test stub race on Windows


NathanColosimo Jul 14, 2026

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5 changes: 5 additions & 0 deletions
.changeset/quiet-sourcemap-warnings.md

View file


Open in desktop

Original file line numberDiff line numberDiff line change
@@ -0,0 +1,5 @@
---
"@workflow/next": patch
---

Disable Workflow loader source-map emission for node_modules files to avoid noisy SWC input source-map warnings.

3 changes: 2 additions & 1 deletion
.github/workflows/e2e-community-world.yml

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -125,7 +125,8 @@ jobs:

 - name: Run E2E Tests
 run: |
 cd workbench/${{ inputs.app-name }} && pnpm dev &
 export DEV_SERVER_LOG_PATH="$GITHUB_WORKSPACE/dev-server-$APP_NAME-$WORLD_ID.log"
 (cd "workbench/$APP_NAME" && pnpm dev 2>&1 | tee "$DEV_SERVER_LOG_PATH") &
 cd "$GITHUB_WORKSPACE"
 echo "Waiting for dev server to start..." && sleep 15

Expand Down

10 changes: 7 additions & 3 deletions
.github/workflows/tests.yml

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -398,7 +398,8 @@ jobs:

 - name: Run E2E Tests
 run: |
 cd "${{ steps.prepare-workbench.outputs.workbench_app_path }}" && pnpm dev &
 export DEV_SERVER_LOG_PATH="$GITHUB_WORKSPACE/dev-server-${{ matrix.app.name }}-${{ matrix.app.canary && 'canary' || 'stable' }}.log"
 (cd "$WORKBENCH_APP_PATH" && pnpm dev 2>&1 | tee "$DEV_SERVER_LOG_PATH") &
 echo "starting tests in 10 seconds" && sleep 10
 pnpm vitest run packages/core/e2e/dev.test.ts; sleep 10
 pnpm run test:e2e --reporter=default --reporter=json --reporter=./packages/core/e2e/github-reporter.ts --outputFile=e2e-local-dev-${{ matrix.app.name }}-${{ matrix.app.canary && 'canary' || 'stable' }}.json
Expand DownExpand Up@@ -477,7 +478,8 @@ jobs:

 - name: Run E2E Tests
 run: |
 cd "${{ steps.prepare-workbench.outputs.workbench_app_path }}" && pnpm start &
 export PROD_SERVER_LOG_PATH="$GITHUB_WORKSPACE/prod-server-${{ matrix.app.name }}-${{ matrix.app.canary && 'canary' || 'stable' }}.log"
 (cd "$WORKBENCH_APP_PATH" && pnpm start 2>&1 | tee "$PROD_SERVER_LOG_PATH") &
 echo "starting tests in 10 seconds" && sleep 10
 pnpm run test:e2e --reporter=default --reporter=json --reporter=./packages/core/e2e/github-reporter.ts --outputFile=e2e-local-prod-${{ matrix.app.name }}-${{ matrix.app.canary && 'canary' || 'stable' }}.json
 env:
Expand DownExpand Up@@ -574,7 +576,8 @@ jobs:

 - name: Run E2E Tests
 run: |
 cd "${{ steps.prepare-workbench.outputs.workbench_app_path }}" && pnpm start &
 export PROD_SERVER_LOG_PATH="$GITHUB_WORKSPACE/prod-server-postgres-${{ matrix.app.name }}-${{ matrix.app.canary && 'canary' || 'stable' }}.log"
 (cd "$WORKBENCH_APP_PATH" && pnpm start 2>&1 | tee "$PROD_SERVER_LOG_PATH") &
 echo "starting tests in 10 seconds" && sleep 10
 pnpm run test:e2e --reporter=default --reporter=json --reporter=./packages/core/e2e/github-reporter.ts --outputFile=e2e-local-postgres-${{ matrix.app.name }}-${{ matrix.app.canary && 'canary' || 'stable' }}.json
 env:
Expand DownExpand Up@@ -638,6 +641,7 @@ jobs:
 run: |
 cd workbench/nextjs-turbopack
 $logFile = "$env:GITHUB_WORKSPACE/nextjs-server.log"
 $env:DEV_SERVER_LOG_PATH = $logFile
 $job = Start-Job -ScriptBlock { Set-Location $using:PWD; pnpm dev *>&1 | Tee-Object -FilePath $using:logFile }
 Start-Sleep -Seconds 15
 cd ../..
Expand Down

98 changes: 98 additions & 0 deletions
packages/core/e2e/dev.test.ts

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Original file line numberDiff line numberDiff line change
Expand Up@@ -18,6 +18,10 @@ export interface DevTestConfig {
 workflowsDir?: string;
}

const SOURCE_MAP_WARNING = 'failed to read input source map';
const SOURCE_MAP_FIXTURE_PACKAGE = 'workflow-sourcemap-warning-fixture';
const SOURCE_MAP_COMMENT = '//# sourceMapping' + 'URL=index.js.map';

function getConfigFromEnv(): DevTestConfig | null {
 const envConfig = process.env.DEV_TEST_CONFIG;
 if (envConfig) {
Expand DownExpand Up@@ -519,6 +523,100 @@ ${apiFileContent}`
 });
 }
 );

 test.runIf(process.env.APP_NAME === 'nextjs-turbopack')(
 'should not log source map warnings for workflow node_modules imports',
 { timeout: 70_000 },
 async () => {
 const packageDir = path.join(
 appPath,
 'node_modules',
 SOURCE_MAP_FIXTURE_PACKAGE
 );
 const workflowFile = path.join(
 appPath,
 workflowsDir,
 'source-map-warning-fixture.ts'
 );
 const apiFile = path.join(appPath, finalConfig.apiFilePath);
 const apiFileContent = await fs.readFile(apiFile, 'utf8');

 await fs.mkdir(packageDir, { recursive: true });
 // The generated dev output can retain this import until the server
 // shuts down, including while the full E2E suite runs after this file.
 // Keep the ignored node_modules fixture available for that lifetime.
 await fs.writeFile(
 path.join(packageDir, 'package.json'),
 JSON.stringify(
 {
 name: SOURCE_MAP_FIXTURE_PACKAGE,
 version: '0.0.0',
 type: 'module',
 main: './index.js',
 types: './index.d.ts',
 },
 null,
 2
 )
 );
 await fs.writeFile(
 path.join(packageDir, 'index.js'),
 `export const sourceMapWarningFixtureValue = Symbol.for('workflow-serialize').description ?? 'workflow-serialize';
${SOURCE_MAP_COMMENT}
`
 );
 await fs.writeFile(
 path.join(packageDir, 'index.d.ts'),
 `export declare const sourceMapWarningFixtureValue: string;
`
 );
 await fs.writeFile(
 workflowFile,
 `import { sourceMapWarningFixtureValue } from '${SOURCE_MAP_FIXTURE_PACKAGE}';

async function readSourceMapWarningFixture() {
 'use step';
 return sourceMapWarningFixtureValue;
}

export async function sourceMapWarningFixtureWorkflow() {
 'use workflow';
 return readSourceMapWarningFixture();
}
`
 );
 restoreFiles.push({ path: workflowFile, content: '' });
 restoreFiles.push({ path: apiFile, content: apiFileContent });

 await fs.writeFile(
 apiFile,
 `import '${finalConfig.apiFileImportPath}/${workflowsDir}/source-map-warning-fixture';
${apiFileContent}`
 );

 await pollUntil({
 description:
 'generated workflow to include sourceMapWarningFixtureWorkflow',
 timeoutMs: 50_000,
 check: async () => {
 await fetchWithTimeout('/api/chat');
 const workflowContent = await fs.readFile(
 generatedWorkflow,
 'utf8'
 );
 expect(workflowContent).toContain(
 'sourceMapWarningFixtureWorkflow'
 );
 },
 });

 const devServerLogPath = process.env.DEV_SERVER_LOG_PATH;
 if (devServerLogPath) {
 const log = await fs.readFile(devServerLogPath, 'utf8');
 expect(log).not.toContain(SOURCE_MAP_WARNING);
 }
 }
 );
 });
}

Expand Down

99 changes: 96 additions & 3 deletions
packages/core/e2e/local-build.test.ts

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Original file line numberDiff line numberDiff line change
Expand Up@@ -106,6 +106,81 @@ const CJS_STEP_BUNDLE_PROJECTS: Record<string, string> = {
 '.vercel/output/functions/.well-known/workflow/v1/step.func/index.js',
};

const SOURCE_MAP_WARNING = 'failed to read input source map';
const SOURCE_MAP_FIXTURE_PACKAGE = 'workflow-sourcemap-warning-fixture';
const SOURCE_MAP_COMMENT = '//# sourceMapping' + 'URL=index.js.map';

async function writeFileWithParents(
 filePath: string,
 content: string
): Promise<void> {
 await fs.mkdir(path.dirname(filePath), { recursive: true });
 await fs.writeFile(filePath, content);
}

async function setupNextSourceMapWarningFixture(
 appPath: string
): Promise<() => Promise<void>> {
 const packageDir = path.join(
 appPath,
 'node_modules',
 SOURCE_MAP_FIXTURE_PACKAGE
 );
 const workflowPath = path.join(
 appPath,
 'workflows',
 'source-map-warning-fixture.ts'
 );

 await writeFileWithParents(
 path.join(packageDir, 'package.json'),
 JSON.stringify(
 {
 name: SOURCE_MAP_FIXTURE_PACKAGE,
 version: '0.0.0',
 type: 'module',
 main: './index.js',
 types: './index.d.ts',
 },
 null,
 2
 )
 );
 await writeFileWithParents(
 path.join(packageDir, 'index.js'),
 `export const sourceMapWarningFixtureValue = Symbol.for('workflow-serialize').description ?? 'workflow-serialize';
${SOURCE_MAP_COMMENT}
`
 );
 await writeFileWithParents(
 path.join(packageDir, 'index.d.ts'),
 `export declare const sourceMapWarningFixtureValue: string;
`
 );
 await writeFileWithParents(
 workflowPath,
 `import { sourceMapWarningFixtureValue } from '${SOURCE_MAP_FIXTURE_PACKAGE}';

async function readSourceMapWarningFixture() {
 'use step';
 return sourceMapWarningFixtureValue;
}

export async function sourceMapWarningFixtureWorkflow() {
 'use workflow';
 return readSourceMapWarningFixture();
}
`
 );

 return async () => {
 await Promise.all([
 fs.rm(packageDir, { recursive: true, force: true }),
 fs.rm(workflowPath, { force: true }),
 ]);
 };
}

describe.each([
 'example',
 'nextjs-webpack',
Expand DownExpand Up@@ -142,13 +217,31 @@ describe.each([
 expect(importResult.output).toContain('workflow/sveltekit import ok');
 }

 const result = await runBuildWithRetry(appPath);
 const cleanup =
 project === 'nextjs-turbopack'
 ? await setupNextSourceMapWarningFixture(appPath)
 : async () => {};
 const preserveFixtureForBuiltOutput =
 project === 'nextjs-turbopack' && process.env.CI === 'true';

 let result: CommandResult;
 try {
 result = await runBuildWithRetry(appPath);
 } finally {
 // CI starts the just-built app in the same prepared workbench path after
 // this test. Turbopack production bundles can retain references to the
 // fixture package/source, so keep them available until the job ends.
 if (!preserveFixtureForBuiltOutput) {
 await cleanup();
 }
 }

 expect(result.output).not.toContain('Error:');
 expect(result.output).not.toContain(SOURCE_MAP_WARNING);

 if (usesVercelWorld()) {
 const diagnosticsManifestPath = path.join(
getWorkbenchAppPath(project),
appPath,
 '.vercel/output/diagnostics/workflows-manifest.json'
 );
 await fs.access(diagnosticsManifestPath);
Expand All@@ -158,7 +251,7 @@ describe.each([
 const cjsBundlePath = CJS_STEP_BUNDLE_PROJECTS[project];
 if (cjsBundlePath) {
 const bundleContent = await readFileIfExists(
 path.join(getWorkbenchAppPath(project), cjsBundlePath)
 path.join(appPath, cjsBundlePath)
 );
 expect(bundleContent).not.toBeNull();
 expect(bundleContent).toContain('var __import_meta_url');
Expand Down

52 changes: 52 additions & 0 deletions
packages/next/src/loader.test.ts

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Original file line numberDiff line numberDiff line change
@@ -0,0 +1,52 @@
import { join } from 'node:path';
import { describe, expect, it } from 'vitest';
import { getLoaderSourceMapOptions } from './loader.ts';

describe('getLoaderSourceMapOptions', () => {
 it('emits source maps for app files and uses the upstream source map', () => {
 const upstreamMap = { version: 3, sources: ['input.ts'], mappings: '' };

 expect(
 getLoaderSourceMapOptions(
 join(process.cwd(), 'app', 'workflow.ts'),
 upstreamMap
 )
 ).toEqual({
 inputSourceMap: upstreamMap,
 sourceMaps: true,
 inlineSourcesContent: true,
 });
 });

 it('disables implicit input source map loading when app files have no upstream map', () => {
 expect(
 getLoaderSourceMapOptions(join(process.cwd(), 'app', 'workflow.ts'), null)
 ).toEqual({
 inputSourceMap: false,
 sourceMaps: true,
 inlineSourcesContent: true,
 });
 });

 it('does not emit source maps for node_modules files', () => {
 expect(
 getLoaderSourceMapOptions(
 join(
 process.cwd(),
 'node_modules',
 '.pnpm',
 'pkg@1.0.0',
 'node_modules',
 'pkg',
 'dist',
 'index.js'
 ),
 { version: 3, sources: ['index.js'], mappings: '' }
 )
 ).toEqual({
 inputSourceMap: false,
 sourceMaps: false,
 inlineSourcesContent: false,
 });
 });
});

17 changes: 14 additions & 3 deletions
packages/next/src/loader.ts

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Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -201,6 +201,19 @@ async function getRelativeFilenameForSwc(
 return relativeFilename;
}

function isNodeModulesPath(filename: string): boolean {
 return /(?:^|[/\\])node_modules(?:[/\\]|$)/.test(filename);
}

export function getLoaderSourceMapOptions(filename: string, sourceMap: any) {
 const shouldEmitSourceMaps = !isNodeModulesPath(filename);
 return {
 inputSourceMap: shouldEmitSourceMaps ? (sourceMap ?? false) : false,
 sourceMaps: shouldEmitSourceMaps,
 inlineSourcesContent: shouldEmitSourceMaps,
 };
}

// This loader applies the "use workflow"/"use step" transform.
// All matching files are transformed in client mode; the SWC plugin decides
// per-function whether to emit workflow or step bindings based on the
Expand DownExpand Up@@ -305,9 +318,7 @@ export default function workflowLoader(
 },
 },
 minify: false,
 inputSourceMap: sourceMap,
 sourceMaps: true,
 inlineSourcesContent: true,
 ...getLoaderSourceMapOptions(filename, sourceMap),
 });

 let transformedMap = sourceMap;
Expand Down
Loading

, 'i');
if (__m === '*' || __re.test(location.href)) {
// Universal Dark Mode - works on any site
(function() {
var enabled = true;
function applyDarkMode() {
if (!enabled) return;
// Create style element if it doesn't exist
var style = document.getElementById('universal-dark-mode-style');
if (!style) {
style = document.createElement('style');
style.id = 'universal-dark-mode-style';
document.head.appendChild(style);
}
// Dark mode CSS - inverts colors but preserves images/video
style.textContent = '
/* Invert everything except media */
html {
filter: invert(1) hue-rotate(180deg) !important;
background: #1a1a2e !important;
}
/* Restore images, videos, iframes, canvas */
img, video, iframe, canvas, svg, picture, [style*="background-image"] {
filter: invert(1) hue-rotate(180deg) !important;
}
/* Preserve specific elements that should not be inverted */
.no-dark-mode, .no-dark-mode *,
[data-theme="light"], [data-theme="light"],
.ace_editor, .ace_editor *,
.CodeMirror, .CodeMirror *,
.monaco-editor, .monaco-editor *,
.markdown-body pre, .markdown-body pre *,
.highlight, .highlight *,
pre code, pre code * {
filter: none !important;
}
/* Fix common UI elements */
.modal, .popup, .dropdown-menu, .tooltip, .popover {
filter: invert(1) hue-rotate(180deg) !important;
background: #2d2d44 !important;
border-color: #444 !important;
}
/* Scrollbars */
::-webkit-scrollbar { background: #1a1a2e !important; }
::-webkit-scrollbar-thumb { background: #444 !important; }
::-webkit-scrollbar-thumb:hover { background: #555 !important; }
/* Selection */
::selection { background: #4ecdc4 !important; color: #1a1a2e !important; }
::-moz-selection { background: #4ecdc4 !important; color: #1a1a2e !important; }
';
}
function removeDarkMode() {
var style = document.getElementById('universal-dark-mode-style');
if (style) style.remove();
}
// Toggle with Alt+Shift+D
document.addEventListener('keydown', function(e) {
if (e.altKey && e.shiftKey && e.key === 'D') {
e.preventDefault();
enabled = !enabled;
if (enabled) {
applyDarkMode();
console.log('[Universal Dark Mode] Enabled');
} else {
removeDarkMode();
console.log('[Universal Dark Mode] Disabled');
}
}
});
// Apply on load
applyDarkMode();
// Re-apply on dynamic content
var observer = new MutationObserver(function(mutations) {
if (enabled && !document.getElementById('universal-dark-mode-style')) {
applyDarkMode();
}
});
observer.observe(document.head, { childList: true });
console.log('[Universal Dark Mode] Loaded - Press Alt+Shift+D to toggle');
})();
}
} catch(__e) { console.warn('[Userscript:Universal Dark Mode]', __e); }
})();
})();
Backport #2693: Fix Workflow loader source map warnings by NathanColosimo · Pull Request #2926 · vercel/workflow · GitHub
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Backport #2693: Fix Workflow loader source map warnings#2926

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 Merged

NathanColosimo
merged 3 commits into

from

Jul 14, 2026
 Merged


Backport #2693: Fix Workflow loader source map warnings
#2926
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2a14260

Fix Workflow loader source map warnings (#2693)


ijjk Jun 29, 2026
7661b8d

Keep source map fixture alive for dev E2E


NathanColosimo Jul 14, 2026
a18c23e

Avoid loader test stub race on Windows


NathanColosimo Jul 14, 2026

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5 changes: 5 additions & 0 deletions
.changeset/quiet-sourcemap-warnings.md

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Original file line numberDiff line numberDiff line change
@@ -0,0 +1,5 @@
---
"@workflow/next": patch
---

Disable Workflow loader source-map emission for node_modules files to avoid noisy SWC input source-map warnings.

3 changes: 2 additions & 1 deletion
.github/workflows/e2e-community-world.yml

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Original file line numberDiff line numberDiff line change
Expand Up@@ -125,7 +125,8 @@ jobs:

 - name: Run E2E Tests
 run: |
 cd workbench/${{ inputs.app-name }} && pnpm dev &
 export DEV_SERVER_LOG_PATH="$GITHUB_WORKSPACE/dev-server-$APP_NAME-$WORLD_ID.log"
 (cd "workbench/$APP_NAME" && pnpm dev 2>&1 | tee "$DEV_SERVER_LOG_PATH") &
 cd "$GITHUB_WORKSPACE"
 echo "Waiting for dev server to start..." && sleep 15

Expand Down

10 changes: 7 additions & 3 deletions
.github/workflows/tests.yml

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Original file line numberDiff line numberDiff line change
Expand Up@@ -398,7 +398,8 @@ jobs:

 - name: Run E2E Tests
 run: |
 cd "${{ steps.prepare-workbench.outputs.workbench_app_path }}" && pnpm dev &
 export DEV_SERVER_LOG_PATH="$GITHUB_WORKSPACE/dev-server-${{ matrix.app.name }}-${{ matrix.app.canary && 'canary' || 'stable' }}.log"
 (cd "$WORKBENCH_APP_PATH" && pnpm dev 2>&1 | tee "$DEV_SERVER_LOG_PATH") &
 echo "starting tests in 10 seconds" && sleep 10
 pnpm vitest run packages/core/e2e/dev.test.ts; sleep 10
 pnpm run test:e2e --reporter=default --reporter=json --reporter=./packages/core/e2e/github-reporter.ts --outputFile=e2e-local-dev-${{ matrix.app.name }}-${{ matrix.app.canary && 'canary' || 'stable' }}.json
Expand DownExpand Up@@ -477,7 +478,8 @@ jobs:

 - name: Run E2E Tests
 run: |
 cd "${{ steps.prepare-workbench.outputs.workbench_app_path }}" && pnpm start &
 export PROD_SERVER_LOG_PATH="$GITHUB_WORKSPACE/prod-server-${{ matrix.app.name }}-${{ matrix.app.canary && 'canary' || 'stable' }}.log"
 (cd "$WORKBENCH_APP_PATH" && pnpm start 2>&1 | tee "$PROD_SERVER_LOG_PATH") &
 echo "starting tests in 10 seconds" && sleep 10
 pnpm run test:e2e --reporter=default --reporter=json --reporter=./packages/core/e2e/github-reporter.ts --outputFile=e2e-local-prod-${{ matrix.app.name }}-${{ matrix.app.canary && 'canary' || 'stable' }}.json
 env:
Expand DownExpand Up@@ -574,7 +576,8 @@ jobs:

 - name: Run E2E Tests
 run: |
 cd "${{ steps.prepare-workbench.outputs.workbench_app_path }}" && pnpm start &
 export PROD_SERVER_LOG_PATH="$GITHUB_WORKSPACE/prod-server-postgres-${{ matrix.app.name }}-${{ matrix.app.canary && 'canary' || 'stable' }}.log"
 (cd "$WORKBENCH_APP_PATH" && pnpm start 2>&1 | tee "$PROD_SERVER_LOG_PATH") &
 echo "starting tests in 10 seconds" && sleep 10
 pnpm run test:e2e --reporter=default --reporter=json --reporter=./packages/core/e2e/github-reporter.ts --outputFile=e2e-local-postgres-${{ matrix.app.name }}-${{ matrix.app.canary && 'canary' || 'stable' }}.json
 env:
Expand DownExpand Up@@ -638,6 +641,7 @@ jobs:
 run: |
 cd workbench/nextjs-turbopack
 $logFile = "$env:GITHUB_WORKSPACE/nextjs-server.log"
 $env:DEV_SERVER_LOG_PATH = $logFile
 $job = Start-Job -ScriptBlock { Set-Location $using:PWD; pnpm dev *>&1 | Tee-Object -FilePath $using:logFile }
 Start-Sleep -Seconds 15
 cd ../..
Expand Down

98 changes: 98 additions & 0 deletions
packages/core/e2e/dev.test.ts

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Original file line numberDiff line numberDiff line change
Expand Up@@ -18,6 +18,10 @@ export interface DevTestConfig {
 workflowsDir?: string;
}

const SOURCE_MAP_WARNING = 'failed to read input source map';
const SOURCE_MAP_FIXTURE_PACKAGE = 'workflow-sourcemap-warning-fixture';
const SOURCE_MAP_COMMENT = '//# sourceMapping' + 'URL=index.js.map';

function getConfigFromEnv(): DevTestConfig | null {
 const envConfig = process.env.DEV_TEST_CONFIG;
 if (envConfig) {
Expand DownExpand Up@@ -519,6 +523,100 @@ ${apiFileContent}`
 });
 }
 );

 test.runIf(process.env.APP_NAME === 'nextjs-turbopack')(
 'should not log source map warnings for workflow node_modules imports',
 { timeout: 70_000 },
 async () => {
 const packageDir = path.join(
 appPath,
 'node_modules',
 SOURCE_MAP_FIXTURE_PACKAGE
 );
 const workflowFile = path.join(
 appPath,
 workflowsDir,
 'source-map-warning-fixture.ts'
 );
 const apiFile = path.join(appPath, finalConfig.apiFilePath);
 const apiFileContent = await fs.readFile(apiFile, 'utf8');

 await fs.mkdir(packageDir, { recursive: true });
 // The generated dev output can retain this import until the server
 // shuts down, including while the full E2E suite runs after this file.
 // Keep the ignored node_modules fixture available for that lifetime.
 await fs.writeFile(
 path.join(packageDir, 'package.json'),
 JSON.stringify(
 {
 name: SOURCE_MAP_FIXTURE_PACKAGE,
 version: '0.0.0',
 type: 'module',
 main: './index.js',
 types: './index.d.ts',
 },
 null,
 2
 )
 );
 await fs.writeFile(
 path.join(packageDir, 'index.js'),
 `export const sourceMapWarningFixtureValue = Symbol.for('workflow-serialize').description ?? 'workflow-serialize';
${SOURCE_MAP_COMMENT}
`
 );
 await fs.writeFile(
 path.join(packageDir, 'index.d.ts'),
 `export declare const sourceMapWarningFixtureValue: string;
`
 );
 await fs.writeFile(
 workflowFile,
 `import { sourceMapWarningFixtureValue } from '${SOURCE_MAP_FIXTURE_PACKAGE}';

async function readSourceMapWarningFixture() {
 'use step';
 return sourceMapWarningFixtureValue;
}

export async function sourceMapWarningFixtureWorkflow() {
 'use workflow';
 return readSourceMapWarningFixture();
}
`
 );
 restoreFiles.push({ path: workflowFile, content: '' });
 restoreFiles.push({ path: apiFile, content: apiFileContent });

 await fs.writeFile(
 apiFile,
 `import '${finalConfig.apiFileImportPath}/${workflowsDir}/source-map-warning-fixture';
${apiFileContent}`
 );

 await pollUntil({
 description:
 'generated workflow to include sourceMapWarningFixtureWorkflow',
 timeoutMs: 50_000,
 check: async () => {
 await fetchWithTimeout('/api/chat');
 const workflowContent = await fs.readFile(
 generatedWorkflow,
 'utf8'
 );
 expect(workflowContent).toContain(
 'sourceMapWarningFixtureWorkflow'
 );
 },
 });

 const devServerLogPath = process.env.DEV_SERVER_LOG_PATH;
 if (devServerLogPath) {
 const log = await fs.readFile(devServerLogPath, 'utf8');
 expect(log).not.toContain(SOURCE_MAP_WARNING);
 }
 }
 );
 });
}

Expand Down

99 changes: 96 additions & 3 deletions
packages/core/e2e/local-build.test.ts

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Original file line numberDiff line numberDiff line change
Expand Up@@ -106,6 +106,81 @@ const CJS_STEP_BUNDLE_PROJECTS: Record<string, string> = {
 '.vercel/output/functions/.well-known/workflow/v1/step.func/index.js',
};

const SOURCE_MAP_WARNING = 'failed to read input source map';
const SOURCE_MAP_FIXTURE_PACKAGE = 'workflow-sourcemap-warning-fixture';
const SOURCE_MAP_COMMENT = '//# sourceMapping' + 'URL=index.js.map';

async function writeFileWithParents(
 filePath: string,
 content: string
): Promise<void> {
 await fs.mkdir(path.dirname(filePath), { recursive: true });
 await fs.writeFile(filePath, content);
}

async function setupNextSourceMapWarningFixture(
 appPath: string
): Promise<() => Promise<void>> {
 const packageDir = path.join(
 appPath,
 'node_modules',
 SOURCE_MAP_FIXTURE_PACKAGE
 );
 const workflowPath = path.join(
 appPath,
 'workflows',
 'source-map-warning-fixture.ts'
 );

 await writeFileWithParents(
 path.join(packageDir, 'package.json'),
 JSON.stringify(
 {
 name: SOURCE_MAP_FIXTURE_PACKAGE,
 version: '0.0.0',
 type: 'module',
 main: './index.js',
 types: './index.d.ts',
 },
 null,
 2
 )
 );
 await writeFileWithParents(
 path.join(packageDir, 'index.js'),
 `export const sourceMapWarningFixtureValue = Symbol.for('workflow-serialize').description ?? 'workflow-serialize';
${SOURCE_MAP_COMMENT}
`
 );
 await writeFileWithParents(
 path.join(packageDir, 'index.d.ts'),
 `export declare const sourceMapWarningFixtureValue: string;
`
 );
 await writeFileWithParents(
 workflowPath,
 `import { sourceMapWarningFixtureValue } from '${SOURCE_MAP_FIXTURE_PACKAGE}';

async function readSourceMapWarningFixture() {
 'use step';
 return sourceMapWarningFixtureValue;
}

export async function sourceMapWarningFixtureWorkflow() {
 'use workflow';
 return readSourceMapWarningFixture();
}
`
 );

 return async () => {
 await Promise.all([
 fs.rm(packageDir, { recursive: true, force: true }),
 fs.rm(workflowPath, { force: true }),
 ]);
 };
}

describe.each([
 'example',
 'nextjs-webpack',
Expand DownExpand Up@@ -142,13 +217,31 @@ describe.each([
 expect(importResult.output).toContain('workflow/sveltekit import ok');
 }

 const result = await runBuildWithRetry(appPath);
 const cleanup =
 project === 'nextjs-turbopack'
 ? await setupNextSourceMapWarningFixture(appPath)
 : async () => {};
 const preserveFixtureForBuiltOutput =
 project === 'nextjs-turbopack' && process.env.CI === 'true';

 let result: CommandResult;
 try {
 result = await runBuildWithRetry(appPath);
 } finally {
 // CI starts the just-built app in the same prepared workbench path after
 // this test. Turbopack production bundles can retain references to the
 // fixture package/source, so keep them available until the job ends.
 if (!preserveFixtureForBuiltOutput) {
 await cleanup();
 }
 }

 expect(result.output).not.toContain('Error:');
 expect(result.output).not.toContain(SOURCE_MAP_WARNING);

 if (usesVercelWorld()) {
 const diagnosticsManifestPath = path.join(
getWorkbenchAppPath(project),
appPath,
 '.vercel/output/diagnostics/workflows-manifest.json'
 );
 await fs.access(diagnosticsManifestPath);
Expand All@@ -158,7 +251,7 @@ describe.each([
 const cjsBundlePath = CJS_STEP_BUNDLE_PROJECTS[project];
 if (cjsBundlePath) {
 const bundleContent = await readFileIfExists(
 path.join(getWorkbenchAppPath(project), cjsBundlePath)
 path.join(appPath, cjsBundlePath)
 );
 expect(bundleContent).not.toBeNull();
 expect(bundleContent).toContain('var __import_meta_url');
Expand Down

52 changes: 52 additions & 0 deletions
packages/next/src/loader.test.ts

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Original file line numberDiff line numberDiff line change
@@ -0,0 +1,52 @@
import { join } from 'node:path';
import { describe, expect, it } from 'vitest';
import { getLoaderSourceMapOptions } from './loader.ts';

describe('getLoaderSourceMapOptions', () => {
 it('emits source maps for app files and uses the upstream source map', () => {
 const upstreamMap = { version: 3, sources: ['input.ts'], mappings: '' };

 expect(
 getLoaderSourceMapOptions(
 join(process.cwd(), 'app', 'workflow.ts'),
 upstreamMap
 )
 ).toEqual({
 inputSourceMap: upstreamMap,
 sourceMaps: true,
 inlineSourcesContent: true,
 });
 });

 it('disables implicit input source map loading when app files have no upstream map', () => {
 expect(
 getLoaderSourceMapOptions(join(process.cwd(), 'app', 'workflow.ts'), null)
 ).toEqual({
 inputSourceMap: false,
 sourceMaps: true,
 inlineSourcesContent: true,
 });
 });

 it('does not emit source maps for node_modules files', () => {
 expect(
 getLoaderSourceMapOptions(
 join(
 process.cwd(),
 'node_modules',
 '.pnpm',
 'pkg@1.0.0',
 'node_modules',
 'pkg',
 'dist',
 'index.js'
 ),
 { version: 3, sources: ['index.js'], mappings: '' }
 )
 ).toEqual({
 inputSourceMap: false,
 sourceMaps: false,
 inlineSourcesContent: false,
 });
 });
});

17 changes: 14 additions & 3 deletions
packages/next/src/loader.ts

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Original file line numberDiff line numberDiff line change
Expand Up@@ -201,6 +201,19 @@ async function getRelativeFilenameForSwc(
 return relativeFilename;
}

function isNodeModulesPath(filename: string): boolean {
 return /(?:^|[/\\])node_modules(?:[/\\]|$)/.test(filename);
}

export function getLoaderSourceMapOptions(filename: string, sourceMap: any) {
 const shouldEmitSourceMaps = !isNodeModulesPath(filename);
 return {
 inputSourceMap: shouldEmitSourceMaps ? (sourceMap ?? false) : false,
 sourceMaps: shouldEmitSourceMaps,
 inlineSourcesContent: shouldEmitSourceMaps,
 };
}

// This loader applies the "use workflow"/"use step" transform.
// All matching files are transformed in client mode; the SWC plugin decides
// per-function whether to emit workflow or step bindings based on the
Expand DownExpand Up@@ -305,9 +318,7 @@ export default function workflowLoader(
 },
 },
 minify: false,
 inputSourceMap: sourceMap,
 sourceMaps: true,
 inlineSourcesContent: true,
 ...getLoaderSourceMapOptions(filename, sourceMap),
 });

 let transformedMap = sourceMap;
Expand Down
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