[v24.x] backport ERR_REQUIRE_ASYNC_MODULE improvements#65125

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Merged
aduh95 merged 2 commits into from
Aug 13, 2026
+493 −134
Merged

[v24.x] backport ERR_REQUIRE_ASYNC_MODULE improvements #65125

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d2b02e4
esm: print required top-level await locations without evaluating
joyeecheung Jul 2, 2026
9e39360
esm: improve ERR_REQUIRE_ASYNC_MODULE
joyeecheung Jul 2, 2026
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9 changes: 6 additions & 3 deletions doc/api/cli.md
View file
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Original file line numberDiff line numberDiff line change
Expand Up@@ -1177,11 +1177,14 @@
added:
- v22.0.0
- v20.17.0
changes:
- version: REPLACEME
pr-url: https://github.com/nodejs/node/pull/64154

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description: Print the top-level awaits without evaluating the modules.
-->

If the ES module being `require()`'d contains top-level `await`, this flag
allows Node.js to evaluate the module, try to locate the
top-level awaits, and print their location to help users find them.
If the ES module graph cannot be `require()`'d because it contains any top-level `await`,
this flag allows Node.js to locate and print their locations.

### `--experimental-quic`

Expand Down
24 changes: 21 additions & 3 deletions doc/api/errors.md
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -2765,12 +2765,30 @@

### `ERR_REQUIRE_ASYNC_MODULE`

<!-- YAML
changes:
- version: REPLACEME
pr-url: https://github.com/nodejs/node/pull/64260

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description: Added the `requireStack` and `topLevelAwaitLocations` properties.
-->

When trying to `require()` an [ES Module][], the module turns out to be asynchronous.
That is, it contains top-level await.

To see where the top-level await is, use
`--experimental-print-required-tla` (this would execute the modules
before looking for the top-level awaits).
When uncaught, the flag `--experimental-print-required-tla` prints
the locations of the top-level awaits in the graph to stderr.

This error has the following additional non-enumerable properties:

* `requireStack` {string\[]} The chain of modules that led to the failing
`require()`, starting with the module that required the asynchronous module.
* `topLevelAwaitLocations` {Object\[]} The locations of the top-level awaits in
the graph. Only populated when `--experimental-print-required-tla` is enabled.
Each entry has the following properties:
* `url` {string} The URL of the module containing the top-level await.
* `line` {number} The 1-based line number of the top-level await.
* `column` {number} The 1-based column number of the top-level await.
* `sourceLine` {string} The source line containing the top-level await.

<a id="ERR_REQUIRE_CYCLE_MODULE"></a>

Expand Down
7 changes: 3 additions & 4 deletions doc/api/modules.md
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -317,10 +317,9 @@ graph it `import`s contains top-level `await`,
[`ERR_REQUIRE_ASYNC_MODULE`][] will be thrown. In this case, users should
load the asynchronous module using [`import()`][].

If `--experimental-print-required-tla` is enabled, instead of throwing
`ERR_REQUIRE_ASYNC_MODULE` before evaluation, Node.js will evaluate the
module, try to locate the top-level awaits, and print their location to
help users fix them.
If `--experimental-print-required-tla` is enabled and the error is uncaught,
Node.js will try to locate the top-level `await`s in the `require()`'d module graph
and print the locations in the stderr.

If support for loading ES modules using `require()` results in unexpected
breakage, it can be disabled using `--no-require-module`.
Expand Down
42 changes: 35 additions & 7 deletions lib/internal/errors.js
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -48,6 +48,7 @@ const {
StringPrototypeEndsWith,
StringPrototypeIncludes,
StringPrototypeIndexOf,
StringPrototypeRepeat,
StringPrototypeSlice,
StringPrototypeSplit,
StringPrototypeStartsWith,
Expand DownExpand Up@@ -1692,15 +1693,42 @@ E('ERR_QUIC_STREAM_ABORTED', '%s', Error);
E('ERR_QUIC_STREAM_RESET',
'The QUIC stream was reset by the peer with error code %d', Error);
E('ERR_QUIC_VERSION_NEGOTIATION_ERROR', 'The QUIC session requires version negotiation', Error);
E('ERR_REQUIRE_ASYNC_MODULE', function(filename, parentFilename) {
let message = 'require() cannot be used on an ESM ' +
'graph with top-level await. Use import() instead. To see where the' +
' top-level await comes from, use --experimental-print-required-tla.';
if (parentFilename) {
message += `\n From ${parentFilename} `;
E('ERR_REQUIRE_ASYNC_MODULE', function(filename, parent, locations) {
let message = 'require() cannot be used on an ESM graph with top-level await. Use import() instead.';
const { getOptionValue } = require('internal/options');
if (!getOptionValue('--experimental-print-required-tla')) {
message += ' To see where the top-level await comes from, use --experimental-print-required-tla.';
}
if (filename) {
message += `\n Requiring ${filename} `;
message += `\nRequired module: ${filename}`;
}
if (parent) {
const { getRequireStack } = require('internal/modules/helpers');
const requireStack = getRequireStack(parent);
if (requireStack.length > 0) {
message += '\nRequire stack:\n- ' +
ArrayPrototypeJoin(requireStack, '\n- ');
}
ObjectDefineProperty(this, 'requireStack', {
__proto__: null,
enumerable: false,
configurable: true,
writable: true,
value: requireStack,
});
}
if (locations && locations.length > 0) {
const { urlToFilename } = require('internal/modules/helpers');
const frames = ArrayPrototypeMap(locations, ({ url, line, column, sourceLine }) =>
`${urlToFilename(url)}:${line}\n\n${sourceLine}\n${StringPrototypeRepeat(' ', column - 1)}^\n`);
setArrowMessage(this, ArrayPrototypeJoin(frames, '\n'));
ObjectDefineProperty(this, 'topLevelAwaitLocations', {
__proto__: null,
enumerable: false,
configurable: true,
writable: true,
value: locations,
});
}
return message;
}, Error);
Expand Down
12 changes: 1 addition & 11 deletions lib/internal/modules/cjs/loader.js
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -168,6 +168,7 @@ const {
setHasStartedUserCJSExecution,
stripBOM,
toRealPath,
getRequireStack,
} = require('internal/modules/helpers');
const {
convertCJSFilenameToURL,
Expand DownExpand Up@@ -1567,17 +1568,6 @@ Module._resolveFilename = function(request, parent, isMain, options) {
throw err;
};

function getRequireStack(parent) {
const requireStack = [];
for (let cursor = parent;
cursor;
// TODO(joyeecheung): it makes more sense to use kLastModuleParent here.
cursor = cursor[kFirstModuleParent]) {
ArrayPrototypePush(requireStack, cursor.filename || cursor.id);
}
return requireStack;
}

function getRequireStackMessage(request, requireStack) {
let message = `Cannot find module '${request}'`;
if (requireStack.length > 0) {
Expand Down
14 changes: 9 additions & 5 deletions lib/internal/modules/esm/loader.js
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -25,7 +25,6 @@ const { imported_cjs_symbol } = internalBinding('symbols');

const assert = require('internal/assert');
const {
ERR_REQUIRE_ASYNC_MODULE,
ERR_REQUIRE_CYCLE_MODULE,
ERR_REQUIRE_ESM,
ERR_REQUIRE_ESM_RACE_CONDITION,
Expand DownExpand Up@@ -289,8 +288,8 @@ class ModuleLoader {
const status = job.module.getStatus();
debug('Module status', job, status);
// hasAsyncGraph is available after module been instantiated.
if (status >= kInstantiated && job.module.hasAsyncGraph) {
throw new ERR_REQUIRE_ASYNC_MODULE(filename, parentFilename);
if (status >= kInstantiated) {
job.throwIfAsyncGraph(parent);
}
if (status === kEvaluated) {
return { wrap: job.module, namespace: job.module.getNamespace() };
Expand DownExpand Up@@ -318,6 +317,11 @@ class ModuleLoader {
}
if (status !== kEvaluating) {
assert(status === kUninstantiated, `Unexpected module status ${status}`);
// If we get here, either there's a race where the job is still being instantiated
// by an in-flight import(), or the cached module previously encountered an
// instantiation error during a prior load (e.g. due to a mismatched import).
// TODO(joyeecheung): the current check is too broad. We should attempt to
// get the potential instantiation error and throw it.
throw new ERR_REQUIRE_ESM_RACE_CONDITION(filename, parentFilename, false);
}
let message = `Cannot require() ES Module ${filename} in a cycle.`;
Expand DownExpand Up@@ -368,8 +372,8 @@ class ModuleLoader {

// Otherwise the module could be imported before but the evaluation may be already
// completed (e.g. the require call is lazy) so it's okay. We will return the
// job and check asynchronicity of the entire graph later, after the
// graph is instantiated.
// job and check asynchronicity of the entire graph later, before the
// graph is evaluated.
}

/**
Expand Down
Loading
, 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Add copy buttons to all 
 blocks\n(function() {\n function addCopyButtons() {\n document.querySelectorAll('pre code').forEach(function(codeBlock) {\n if (codeBlock.parentElement.hasAttribute('data-copy-added')) return;\n codeBlock.parentElement.setAttribute('data-copy-added', 'true');\n \n var btn = document.createElement('button');\n btn.textContent = 'Copy';\n 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;';\n btn.onmouseover = function() { this.style.opacity = '1'; };\n btn.onmouseout = function() { this.style.opacity = '0.7'; };\n btn.onclick = function() {\n navigator.clipboard.writeText(codeBlock.textContent).then(function() {\n btn.textContent = 'Copied!';\n setTimeout(function() { btn.textContent = 'Copy'; }, 1500);\n });\n };\n codeBlock.parentElement.style.position = 'relative';\n codeBlock.parentElement.appendChild(btn);\n });\n }\n \n addCopyButtons();\n \n // Re-run on dynamic content\n var observer = new MutationObserver(addCopyButtons);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Add Copy Buttons to Code Blocks");
}
} catch(__e) { console.warn('[Userscript:Add Copy Buttons to Code Blocks]', __e); }
})();
(function(){
try {
var __m = "github.com";
var __re = new RegExp('^' + "github\\.com" + '

Skip to content
[v24.x] backport ERR_REQUIRE_ASYNC_MODULE improvements#65125

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to your account

 Merged

aduh95
merged 2 commits into

from

Aug 13, 2026

+493

−134

 Merged


[v24.x] backport ERR_REQUIRE_ASYNC_MODULE improvements
#65125
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d2b02e4

esm: print required top-level await locations without evaluating


joyeecheung Jul 2, 2026
9e39360

esm: improve ERR_REQUIRE_ASYNC_MODULE


joyeecheung Jul 2, 2026

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9 changes: 6 additions & 3 deletions
doc/api/cli.md

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -1177,11 +1177,14 @@
added:
 - v22.0.0
 - v20.17.0
changes:
 - version: REPLACEME
 pr-url: https://github.com/nodejs/node/pull/64154

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pr-url doesn't match the URL of the current PR.
 description: Print the top-level awaits without evaluating the modules.
-->

If the ES module being `require()`'d contains top-level `await`, this flag
allows Node.js to evaluate the module, try to locate the
top-level awaits, and print their location to help users find them.
If the ES module graph cannot be `require()`'d because it contains any top-level `await`,
this flag allows Node.js to locate and print their locations.

### `--experimental-quic`

Expand Down

24 changes: 21 additions & 3 deletions
doc/api/errors.md

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -2765,12 +2765,30 @@

### `ERR_REQUIRE_ASYNC_MODULE`

<!-- YAML
changes:
 - version: REPLACEME
 pr-url: https://github.com/nodejs/node/pull/64260

Check warning
on line 2771
in doc/api/errors.md

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GitHub Actions/ lint-pr-url
pr-url doesn't match the URL of the current PR.
 description: Added the `requireStack` and `topLevelAwaitLocations` properties.
-->

When trying to `require()` an [ES Module][], the module turns out to be asynchronous.
That is, it contains top-level await.

To see where the top-level await is, use
`--experimental-print-required-tla` (this would execute the modules
before looking for the top-level awaits).
When uncaught, the flag `--experimental-print-required-tla` prints
the locations of the top-level awaits in the graph to stderr.

This error has the following additional non-enumerable properties:

* `requireStack` {string\[]} The chain of modules that led to the failing
 `require()`, starting with the module that required the asynchronous module.
* `topLevelAwaitLocations` {Object\[]} The locations of the top-level awaits in
 the graph. Only populated when `--experimental-print-required-tla` is enabled.
 Each entry has the following properties:
 * `url` {string} The URL of the module containing the top-level await.
 * `line` {number} The 1-based line number of the top-level await.
 * `column` {number} The 1-based column number of the top-level await.
 * `sourceLine` {string} The source line containing the top-level await.

<a id="ERR_REQUIRE_CYCLE_MODULE"></a>

Expand Down

7 changes: 3 additions & 4 deletions
doc/api/modules.md

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -317,10 +317,9 @@ graph it `import`s contains top-level `await`,
[`ERR_REQUIRE_ASYNC_MODULE`][] will be thrown. In this case, users should
load the asynchronous module using [`import()`][].

If `--experimental-print-required-tla` is enabled, instead of throwing
`ERR_REQUIRE_ASYNC_MODULE` before evaluation, Node.js will evaluate the
module, try to locate the top-level awaits, and print their location to
help users fix them.
If `--experimental-print-required-tla` is enabled and the error is uncaught,
Node.js will try to locate the top-level `await`s in the `require()`'d module graph
and print the locations in the stderr.

If support for loading ES modules using `require()` results in unexpected
breakage, it can be disabled using `--no-require-module`.
Expand Down

42 changes: 35 additions & 7 deletions
lib/internal/errors.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -48,6 +48,7 @@ const {
 StringPrototypeEndsWith,
 StringPrototypeIncludes,
 StringPrototypeIndexOf,
 StringPrototypeRepeat,
 StringPrototypeSlice,
 StringPrototypeSplit,
 StringPrototypeStartsWith,
Expand DownExpand Up@@ -1692,15 +1693,42 @@ E('ERR_QUIC_STREAM_ABORTED', '%s', Error);
E('ERR_QUIC_STREAM_RESET',
 'The QUIC stream was reset by the peer with error code %d', Error);
E('ERR_QUIC_VERSION_NEGOTIATION_ERROR', 'The QUIC session requires version negotiation', Error);
E('ERR_REQUIRE_ASYNC_MODULE', function(filename, parentFilename) {
 let message = 'require() cannot be used on an ESM ' +
 'graph with top-level await. Use import() instead. To see where the' +
 ' top-level await comes from, use --experimental-print-required-tla.';
 if (parentFilename) {
 message += `\n From ${parentFilename} `;
E('ERR_REQUIRE_ASYNC_MODULE', function(filename, parent, locations) {
 let message = 'require() cannot be used on an ESM graph with top-level await. Use import() instead.';
 const { getOptionValue } = require('internal/options');
 if (!getOptionValue('--experimental-print-required-tla')) {
 message += ' To see where the top-level await comes from, use --experimental-print-required-tla.';
 }
 if (filename) {
 message += `\n Requiring ${filename} `;
 message += `\nRequired module: ${filename}`;
 }
 if (parent) {
 const { getRequireStack } = require('internal/modules/helpers');
 const requireStack = getRequireStack(parent);
 if (requireStack.length > 0) {
 message += '\nRequire stack:\n- ' +
 ArrayPrototypeJoin(requireStack, '\n- ');
 }
 ObjectDefineProperty(this, 'requireStack', {
 __proto__: null,
 enumerable: false,
 configurable: true,
 writable: true,
 value: requireStack,
 });
 }
 if (locations && locations.length > 0) {
 const { urlToFilename } = require('internal/modules/helpers');
 const frames = ArrayPrototypeMap(locations, ({ url, line, column, sourceLine }) =>
 `${urlToFilename(url)}:${line}\n\n${sourceLine}\n${StringPrototypeRepeat(' ', column - 1)}^\n`);
 setArrowMessage(this, ArrayPrototypeJoin(frames, '\n'));
 ObjectDefineProperty(this, 'topLevelAwaitLocations', {
 __proto__: null,
 enumerable: false,
 configurable: true,
 writable: true,
 value: locations,
 });
 }
 return message;
}, Error);
Expand Down

12 changes: 1 addition & 11 deletions
lib/internal/modules/cjs/loader.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -168,6 +168,7 @@ const {
 setHasStartedUserCJSExecution,
 stripBOM,
 toRealPath,
 getRequireStack,
} = require('internal/modules/helpers');
const {
 convertCJSFilenameToURL,
Expand DownExpand Up@@ -1567,17 +1568,6 @@ Module._resolveFilename = function(request, parent, isMain, options) {
 throw err;
};

function getRequireStack(parent) {
 const requireStack = [];
 for (let cursor = parent;
 cursor;
 // TODO(joyeecheung): it makes more sense to use kLastModuleParent here.
 cursor = cursor[kFirstModuleParent]) {
 ArrayPrototypePush(requireStack, cursor.filename || cursor.id);
 }
 return requireStack;
}

function getRequireStackMessage(request, requireStack) {
 let message = `Cannot find module '${request}'`;
 if (requireStack.length > 0) {
Expand Down

14 changes: 9 additions & 5 deletions
lib/internal/modules/esm/loader.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -25,7 +25,6 @@ const { imported_cjs_symbol } = internalBinding('symbols');

const assert = require('internal/assert');
const {
 ERR_REQUIRE_ASYNC_MODULE,
 ERR_REQUIRE_CYCLE_MODULE,
 ERR_REQUIRE_ESM,
 ERR_REQUIRE_ESM_RACE_CONDITION,
Expand DownExpand Up@@ -289,8 +288,8 @@ class ModuleLoader {
 const status = job.module.getStatus();
 debug('Module status', job, status);
 // hasAsyncGraph is available after module been instantiated.
 if (status >= kInstantiated && job.module.hasAsyncGraph) {
throw new ERR_REQUIRE_ASYNC_MODULE(filename, parentFilename);
 if (status >= kInstantiated) {
job.throwIfAsyncGraph(parent);
 }
 if (status === kEvaluated) {
 return { wrap: job.module, namespace: job.module.getNamespace() };
Expand DownExpand Up@@ -318,6 +317,11 @@ class ModuleLoader {
 }
 if (status !== kEvaluating) {
 assert(status === kUninstantiated, `Unexpected module status ${status}`);
 // If we get here, either there's a race where the job is still being instantiated
 // by an in-flight import(), or the cached module previously encountered an
 // instantiation error during a prior load (e.g. due to a mismatched import).
 // TODO(joyeecheung): the current check is too broad. We should attempt to
 // get the potential instantiation error and throw it.
 throw new ERR_REQUIRE_ESM_RACE_CONDITION(filename, parentFilename, false);
 }
 let message = `Cannot require() ES Module ${filename} in a cycle.`;
Expand DownExpand Up@@ -368,8 +372,8 @@ class ModuleLoader {

 // Otherwise the module could be imported before but the evaluation may be already
 // completed (e.g. the require call is lazy) so it's okay. We will return the
 // job and check asynchronicity of the entire graph later, after the
 // graph is instantiated.
 // job and check asynchronicity of the entire graph later, before the
 // graph is evaluated.
 }

 /**
Expand Down
Loading

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

Skip to content
[v24.x] backport ERR_REQUIRE_ASYNC_MODULE improvements#65125

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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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Already on GitHub?
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 Merged

aduh95
merged 2 commits into

from

Aug 13, 2026

+493

−134

 Merged


[v24.x] backport ERR_REQUIRE_ASYNC_MODULE improvements
#65125
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d2b02e4

esm: print required top-level await locations without evaluating


joyeecheung Jul 2, 2026
9e39360

esm: improve ERR_REQUIRE_ASYNC_MODULE


joyeecheung Jul 2, 2026

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9 changes: 6 additions & 3 deletions
doc/api/cli.md

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Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -1177,11 +1177,14 @@
added:
 - v22.0.0
 - v20.17.0
changes:
 - version: REPLACEME
 pr-url: https://github.com/nodejs/node/pull/64154

Check warning
on line 1182
in doc/api/cli.md

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GitHub Actions/ lint-pr-url
pr-url doesn't match the URL of the current PR.
 description: Print the top-level awaits without evaluating the modules.
-->

If the ES module being `require()`'d contains top-level `await`, this flag
allows Node.js to evaluate the module, try to locate the
top-level awaits, and print their location to help users find them.
If the ES module graph cannot be `require()`'d because it contains any top-level `await`,
this flag allows Node.js to locate and print their locations.

### `--experimental-quic`

Expand Down

24 changes: 21 additions & 3 deletions
doc/api/errors.md

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -2765,12 +2765,30 @@

### `ERR_REQUIRE_ASYNC_MODULE`

<!-- YAML
changes:
 - version: REPLACEME
 pr-url: https://github.com/nodejs/node/pull/64260

Check warning
on line 2771
in doc/api/errors.md

View workflow job for this annotation
GitHub Actions/ lint-pr-url
pr-url doesn't match the URL of the current PR.
 description: Added the `requireStack` and `topLevelAwaitLocations` properties.
-->

When trying to `require()` an [ES Module][], the module turns out to be asynchronous.
That is, it contains top-level await.

To see where the top-level await is, use
`--experimental-print-required-tla` (this would execute the modules
before looking for the top-level awaits).
When uncaught, the flag `--experimental-print-required-tla` prints
the locations of the top-level awaits in the graph to stderr.

This error has the following additional non-enumerable properties:

* `requireStack` {string\[]} The chain of modules that led to the failing
 `require()`, starting with the module that required the asynchronous module.
* `topLevelAwaitLocations` {Object\[]} The locations of the top-level awaits in
 the graph. Only populated when `--experimental-print-required-tla` is enabled.
 Each entry has the following properties:
 * `url` {string} The URL of the module containing the top-level await.
 * `line` {number} The 1-based line number of the top-level await.
 * `column` {number} The 1-based column number of the top-level await.
 * `sourceLine` {string} The source line containing the top-level await.

<a id="ERR_REQUIRE_CYCLE_MODULE"></a>

Expand Down

7 changes: 3 additions & 4 deletions
doc/api/modules.md

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -317,10 +317,9 @@ graph it `import`s contains top-level `await`,
[`ERR_REQUIRE_ASYNC_MODULE`][] will be thrown. In this case, users should
load the asynchronous module using [`import()`][].

If `--experimental-print-required-tla` is enabled, instead of throwing
`ERR_REQUIRE_ASYNC_MODULE` before evaluation, Node.js will evaluate the
module, try to locate the top-level awaits, and print their location to
help users fix them.
If `--experimental-print-required-tla` is enabled and the error is uncaught,
Node.js will try to locate the top-level `await`s in the `require()`'d module graph
and print the locations in the stderr.

If support for loading ES modules using `require()` results in unexpected
breakage, it can be disabled using `--no-require-module`.
Expand Down

42 changes: 35 additions & 7 deletions
lib/internal/errors.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -48,6 +48,7 @@ const {
 StringPrototypeEndsWith,
 StringPrototypeIncludes,
 StringPrototypeIndexOf,
 StringPrototypeRepeat,
 StringPrototypeSlice,
 StringPrototypeSplit,
 StringPrototypeStartsWith,
Expand DownExpand Up@@ -1692,15 +1693,42 @@ E('ERR_QUIC_STREAM_ABORTED', '%s', Error);
E('ERR_QUIC_STREAM_RESET',
 'The QUIC stream was reset by the peer with error code %d', Error);
E('ERR_QUIC_VERSION_NEGOTIATION_ERROR', 'The QUIC session requires version negotiation', Error);
E('ERR_REQUIRE_ASYNC_MODULE', function(filename, parentFilename) {
 let message = 'require() cannot be used on an ESM ' +
 'graph with top-level await. Use import() instead. To see where the' +
 ' top-level await comes from, use --experimental-print-required-tla.';
 if (parentFilename) {
 message += `\n From ${parentFilename} `;
E('ERR_REQUIRE_ASYNC_MODULE', function(filename, parent, locations) {
 let message = 'require() cannot be used on an ESM graph with top-level await. Use import() instead.';
 const { getOptionValue } = require('internal/options');
 if (!getOptionValue('--experimental-print-required-tla')) {
 message += ' To see where the top-level await comes from, use --experimental-print-required-tla.';
 }
 if (filename) {
 message += `\n Requiring ${filename} `;
 message += `\nRequired module: ${filename}`;
 }
 if (parent) {
 const { getRequireStack } = require('internal/modules/helpers');
 const requireStack = getRequireStack(parent);
 if (requireStack.length > 0) {
 message += '\nRequire stack:\n- ' +
 ArrayPrototypeJoin(requireStack, '\n- ');
 }
 ObjectDefineProperty(this, 'requireStack', {
 __proto__: null,
 enumerable: false,
 configurable: true,
 writable: true,
 value: requireStack,
 });
 }
 if (locations && locations.length > 0) {
 const { urlToFilename } = require('internal/modules/helpers');
 const frames = ArrayPrototypeMap(locations, ({ url, line, column, sourceLine }) =>
 `${urlToFilename(url)}:${line}\n\n${sourceLine}\n${StringPrototypeRepeat(' ', column - 1)}^\n`);
 setArrowMessage(this, ArrayPrototypeJoin(frames, '\n'));
 ObjectDefineProperty(this, 'topLevelAwaitLocations', {
 __proto__: null,
 enumerable: false,
 configurable: true,
 writable: true,
 value: locations,
 });
 }
 return message;
}, Error);
Expand Down

12 changes: 1 addition & 11 deletions
lib/internal/modules/cjs/loader.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -168,6 +168,7 @@ const {
 setHasStartedUserCJSExecution,
 stripBOM,
 toRealPath,
 getRequireStack,
} = require('internal/modules/helpers');
const {
 convertCJSFilenameToURL,
Expand DownExpand Up@@ -1567,17 +1568,6 @@ Module._resolveFilename = function(request, parent, isMain, options) {
 throw err;
};

function getRequireStack(parent) {
 const requireStack = [];
 for (let cursor = parent;
 cursor;
 // TODO(joyeecheung): it makes more sense to use kLastModuleParent here.
 cursor = cursor[kFirstModuleParent]) {
 ArrayPrototypePush(requireStack, cursor.filename || cursor.id);
 }
 return requireStack;
}

function getRequireStackMessage(request, requireStack) {
 let message = `Cannot find module '${request}'`;
 if (requireStack.length > 0) {
Expand Down

14 changes: 9 additions & 5 deletions
lib/internal/modules/esm/loader.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -25,7 +25,6 @@ const { imported_cjs_symbol } = internalBinding('symbols');

const assert = require('internal/assert');
const {
 ERR_REQUIRE_ASYNC_MODULE,
 ERR_REQUIRE_CYCLE_MODULE,
 ERR_REQUIRE_ESM,
 ERR_REQUIRE_ESM_RACE_CONDITION,
Expand DownExpand Up@@ -289,8 +288,8 @@ class ModuleLoader {
 const status = job.module.getStatus();
 debug('Module status', job, status);
 // hasAsyncGraph is available after module been instantiated.
 if (status >= kInstantiated && job.module.hasAsyncGraph) {
throw new ERR_REQUIRE_ASYNC_MODULE(filename, parentFilename);
 if (status >= kInstantiated) {
job.throwIfAsyncGraph(parent);
 }
 if (status === kEvaluated) {
 return { wrap: job.module, namespace: job.module.getNamespace() };
Expand DownExpand Up@@ -318,6 +317,11 @@ class ModuleLoader {
 }
 if (status !== kEvaluating) {
 assert(status === kUninstantiated, `Unexpected module status ${status}`);
 // If we get here, either there's a race where the job is still being instantiated
 // by an in-flight import(), or the cached module previously encountered an
 // instantiation error during a prior load (e.g. due to a mismatched import).
 // TODO(joyeecheung): the current check is too broad. We should attempt to
 // get the potential instantiation error and throw it.
 throw new ERR_REQUIRE_ESM_RACE_CONDITION(filename, parentFilename, false);
 }
 let message = `Cannot require() ES Module ${filename} in a cycle.`;
Expand DownExpand Up@@ -368,8 +372,8 @@ class ModuleLoader {

 // Otherwise the module could be imported before but the evaluation may be already
 // completed (e.g. the require call is lazy) so it's okay. We will return the
 // job and check asynchronicity of the entire graph later, after the
 // graph is instantiated.
 // job and check asynchronicity of the entire graph later, before the
 // graph is evaluated.
 }

 /**
Expand Down
Loading

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

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[v24.x] backport ERR_REQUIRE_ASYNC_MODULE improvements#65125

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 Merged

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merged 2 commits into

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Aug 13, 2026

+493

−134

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[v24.x] backport ERR_REQUIRE_ASYNC_MODULE improvements
#65125
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d2b02e4

esm: print required top-level await locations without evaluating


joyeecheung Jul 2, 2026
9e39360

esm: improve ERR_REQUIRE_ASYNC_MODULE


joyeecheung Jul 2, 2026

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9 changes: 6 additions & 3 deletions
doc/api/cli.md

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Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -1177,11 +1177,14 @@
added:
 - v22.0.0
 - v20.17.0
changes:
 - version: REPLACEME
 pr-url: https://github.com/nodejs/node/pull/64154

Check warning
on line 1182
in doc/api/cli.md

View workflow job for this annotation
GitHub Actions/ lint-pr-url
pr-url doesn't match the URL of the current PR.
 description: Print the top-level awaits without evaluating the modules.
-->

If the ES module being `require()`'d contains top-level `await`, this flag
allows Node.js to evaluate the module, try to locate the
top-level awaits, and print their location to help users find them.
If the ES module graph cannot be `require()`'d because it contains any top-level `await`,
this flag allows Node.js to locate and print their locations.

### `--experimental-quic`

Expand Down

24 changes: 21 additions & 3 deletions
doc/api/errors.md

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -2765,12 +2765,30 @@

### `ERR_REQUIRE_ASYNC_MODULE`

<!-- YAML
changes:
 - version: REPLACEME
 pr-url: https://github.com/nodejs/node/pull/64260

Check warning
on line 2771
in doc/api/errors.md

View workflow job for this annotation
GitHub Actions/ lint-pr-url
pr-url doesn't match the URL of the current PR.
 description: Added the `requireStack` and `topLevelAwaitLocations` properties.
-->

When trying to `require()` an [ES Module][], the module turns out to be asynchronous.
That is, it contains top-level await.

To see where the top-level await is, use
`--experimental-print-required-tla` (this would execute the modules
before looking for the top-level awaits).
When uncaught, the flag `--experimental-print-required-tla` prints
the locations of the top-level awaits in the graph to stderr.

This error has the following additional non-enumerable properties:

* `requireStack` {string\[]} The chain of modules that led to the failing
 `require()`, starting with the module that required the asynchronous module.
* `topLevelAwaitLocations` {Object\[]} The locations of the top-level awaits in
 the graph. Only populated when `--experimental-print-required-tla` is enabled.
 Each entry has the following properties:
 * `url` {string} The URL of the module containing the top-level await.
 * `line` {number} The 1-based line number of the top-level await.
 * `column` {number} The 1-based column number of the top-level await.
 * `sourceLine` {string} The source line containing the top-level await.

<a id="ERR_REQUIRE_CYCLE_MODULE"></a>

Expand Down

7 changes: 3 additions & 4 deletions
doc/api/modules.md

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -317,10 +317,9 @@ graph it `import`s contains top-level `await`,
[`ERR_REQUIRE_ASYNC_MODULE`][] will be thrown. In this case, users should
load the asynchronous module using [`import()`][].

If `--experimental-print-required-tla` is enabled, instead of throwing
`ERR_REQUIRE_ASYNC_MODULE` before evaluation, Node.js will evaluate the
module, try to locate the top-level awaits, and print their location to
help users fix them.
If `--experimental-print-required-tla` is enabled and the error is uncaught,
Node.js will try to locate the top-level `await`s in the `require()`'d module graph
and print the locations in the stderr.

If support for loading ES modules using `require()` results in unexpected
breakage, it can be disabled using `--no-require-module`.
Expand Down

42 changes: 35 additions & 7 deletions
lib/internal/errors.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -48,6 +48,7 @@ const {
 StringPrototypeEndsWith,
 StringPrototypeIncludes,
 StringPrototypeIndexOf,
 StringPrototypeRepeat,
 StringPrototypeSlice,
 StringPrototypeSplit,
 StringPrototypeStartsWith,
Expand DownExpand Up@@ -1692,15 +1693,42 @@ E('ERR_QUIC_STREAM_ABORTED', '%s', Error);
E('ERR_QUIC_STREAM_RESET',
 'The QUIC stream was reset by the peer with error code %d', Error);
E('ERR_QUIC_VERSION_NEGOTIATION_ERROR', 'The QUIC session requires version negotiation', Error);
E('ERR_REQUIRE_ASYNC_MODULE', function(filename, parentFilename) {
 let message = 'require() cannot be used on an ESM ' +
 'graph with top-level await. Use import() instead. To see where the' +
 ' top-level await comes from, use --experimental-print-required-tla.';
 if (parentFilename) {
 message += `\n From ${parentFilename} `;
E('ERR_REQUIRE_ASYNC_MODULE', function(filename, parent, locations) {
 let message = 'require() cannot be used on an ESM graph with top-level await. Use import() instead.';
 const { getOptionValue } = require('internal/options');
 if (!getOptionValue('--experimental-print-required-tla')) {
 message += ' To see where the top-level await comes from, use --experimental-print-required-tla.';
 }
 if (filename) {
 message += `\n Requiring ${filename} `;
 message += `\nRequired module: ${filename}`;
 }
 if (parent) {
 const { getRequireStack } = require('internal/modules/helpers');
 const requireStack = getRequireStack(parent);
 if (requireStack.length > 0) {
 message += '\nRequire stack:\n- ' +
 ArrayPrototypeJoin(requireStack, '\n- ');
 }
 ObjectDefineProperty(this, 'requireStack', {
 __proto__: null,
 enumerable: false,
 configurable: true,
 writable: true,
 value: requireStack,
 });
 }
 if (locations && locations.length > 0) {
 const { urlToFilename } = require('internal/modules/helpers');
 const frames = ArrayPrototypeMap(locations, ({ url, line, column, sourceLine }) =>
 `${urlToFilename(url)}:${line}\n\n${sourceLine}\n${StringPrototypeRepeat(' ', column - 1)}^\n`);
 setArrowMessage(this, ArrayPrototypeJoin(frames, '\n'));
 ObjectDefineProperty(this, 'topLevelAwaitLocations', {
 __proto__: null,
 enumerable: false,
 configurable: true,
 writable: true,
 value: locations,
 });
 }
 return message;
}, Error);
Expand Down

12 changes: 1 addition & 11 deletions
lib/internal/modules/cjs/loader.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -168,6 +168,7 @@ const {
 setHasStartedUserCJSExecution,
 stripBOM,
 toRealPath,
 getRequireStack,
} = require('internal/modules/helpers');
const {
 convertCJSFilenameToURL,
Expand DownExpand Up@@ -1567,17 +1568,6 @@ Module._resolveFilename = function(request, parent, isMain, options) {
 throw err;
};

function getRequireStack(parent) {
 const requireStack = [];
 for (let cursor = parent;
 cursor;
 // TODO(joyeecheung): it makes more sense to use kLastModuleParent here.
 cursor = cursor[kFirstModuleParent]) {
 ArrayPrototypePush(requireStack, cursor.filename || cursor.id);
 }
 return requireStack;
}

function getRequireStackMessage(request, requireStack) {
 let message = `Cannot find module '${request}'`;
 if (requireStack.length > 0) {
Expand Down

14 changes: 9 additions & 5 deletions
lib/internal/modules/esm/loader.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -25,7 +25,6 @@ const { imported_cjs_symbol } = internalBinding('symbols');

const assert = require('internal/assert');
const {
 ERR_REQUIRE_ASYNC_MODULE,
 ERR_REQUIRE_CYCLE_MODULE,
 ERR_REQUIRE_ESM,
 ERR_REQUIRE_ESM_RACE_CONDITION,
Expand DownExpand Up@@ -289,8 +288,8 @@ class ModuleLoader {
 const status = job.module.getStatus();
 debug('Module status', job, status);
 // hasAsyncGraph is available after module been instantiated.
 if (status >= kInstantiated && job.module.hasAsyncGraph) {
throw new ERR_REQUIRE_ASYNC_MODULE(filename, parentFilename);
 if (status >= kInstantiated) {
job.throwIfAsyncGraph(parent);
 }
 if (status === kEvaluated) {
 return { wrap: job.module, namespace: job.module.getNamespace() };
Expand DownExpand Up@@ -318,6 +317,11 @@ class ModuleLoader {
 }
 if (status !== kEvaluating) {
 assert(status === kUninstantiated, `Unexpected module status ${status}`);
 // If we get here, either there's a race where the job is still being instantiated
 // by an in-flight import(), or the cached module previously encountered an
 // instantiation error during a prior load (e.g. due to a mismatched import).
 // TODO(joyeecheung): the current check is too broad. We should attempt to
 // get the potential instantiation error and throw it.
 throw new ERR_REQUIRE_ESM_RACE_CONDITION(filename, parentFilename, false);
 }
 let message = `Cannot require() ES Module ${filename} in a cycle.`;
Expand DownExpand Up@@ -368,8 +372,8 @@ class ModuleLoader {

 // Otherwise the module could be imported before but the evaluation may be already
 // completed (e.g. the require call is lazy) so it's okay. We will return the
 // job and check asynchronicity of the entire graph later, after the
 // graph is instantiated.
 // job and check asynchronicity of the entire graph later, before the
 // graph is evaluated.
 }

 /**
Expand Down
Loading

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

Skip to content
[v24.x] backport ERR_REQUIRE_ASYNC_MODULE improvements#65125

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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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privacy statement. We’ll occasionally send you account related emails.

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 Merged

aduh95
merged 2 commits into

from

Aug 13, 2026

+493

−134

 Merged


[v24.x] backport ERR_REQUIRE_ASYNC_MODULE improvements
#65125
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d2b02e4

esm: print required top-level await locations without evaluating


joyeecheung Jul 2, 2026
9e39360

esm: improve ERR_REQUIRE_ASYNC_MODULE


joyeecheung Jul 2, 2026

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9 changes: 6 additions & 3 deletions
doc/api/cli.md

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -1177,11 +1177,14 @@
added:
 - v22.0.0
 - v20.17.0
changes:
 - version: REPLACEME
 pr-url: https://github.com/nodejs/node/pull/64154

Check warning
on line 1182
in doc/api/cli.md

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GitHub Actions/ lint-pr-url
pr-url doesn't match the URL of the current PR.
 description: Print the top-level awaits without evaluating the modules.
-->

If the ES module being `require()`'d contains top-level `await`, this flag
allows Node.js to evaluate the module, try to locate the
top-level awaits, and print their location to help users find them.
If the ES module graph cannot be `require()`'d because it contains any top-level `await`,
this flag allows Node.js to locate and print their locations.

### `--experimental-quic`

Expand Down

24 changes: 21 additions & 3 deletions
doc/api/errors.md

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -2765,12 +2765,30 @@

### `ERR_REQUIRE_ASYNC_MODULE`

<!-- YAML
changes:
 - version: REPLACEME
 pr-url: https://github.com/nodejs/node/pull/64260

Check warning
on line 2771
in doc/api/errors.md

View workflow job for this annotation
GitHub Actions/ lint-pr-url
pr-url doesn't match the URL of the current PR.
 description: Added the `requireStack` and `topLevelAwaitLocations` properties.
-->

When trying to `require()` an [ES Module][], the module turns out to be asynchronous.
That is, it contains top-level await.

To see where the top-level await is, use
`--experimental-print-required-tla` (this would execute the modules
before looking for the top-level awaits).
When uncaught, the flag `--experimental-print-required-tla` prints
the locations of the top-level awaits in the graph to stderr.

This error has the following additional non-enumerable properties:

* `requireStack` {string\[]} The chain of modules that led to the failing
 `require()`, starting with the module that required the asynchronous module.
* `topLevelAwaitLocations` {Object\[]} The locations of the top-level awaits in
 the graph. Only populated when `--experimental-print-required-tla` is enabled.
 Each entry has the following properties:
 * `url` {string} The URL of the module containing the top-level await.
 * `line` {number} The 1-based line number of the top-level await.
 * `column` {number} The 1-based column number of the top-level await.
 * `sourceLine` {string} The source line containing the top-level await.

<a id="ERR_REQUIRE_CYCLE_MODULE"></a>

Expand Down

7 changes: 3 additions & 4 deletions
doc/api/modules.md

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -317,10 +317,9 @@ graph it `import`s contains top-level `await`,
[`ERR_REQUIRE_ASYNC_MODULE`][] will be thrown. In this case, users should
load the asynchronous module using [`import()`][].

If `--experimental-print-required-tla` is enabled, instead of throwing
`ERR_REQUIRE_ASYNC_MODULE` before evaluation, Node.js will evaluate the
module, try to locate the top-level awaits, and print their location to
help users fix them.
If `--experimental-print-required-tla` is enabled and the error is uncaught,
Node.js will try to locate the top-level `await`s in the `require()`'d module graph
and print the locations in the stderr.

If support for loading ES modules using `require()` results in unexpected
breakage, it can be disabled using `--no-require-module`.
Expand Down

42 changes: 35 additions & 7 deletions
lib/internal/errors.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -48,6 +48,7 @@ const {
 StringPrototypeEndsWith,
 StringPrototypeIncludes,
 StringPrototypeIndexOf,
 StringPrototypeRepeat,
 StringPrototypeSlice,
 StringPrototypeSplit,
 StringPrototypeStartsWith,
Expand DownExpand Up@@ -1692,15 +1693,42 @@ E('ERR_QUIC_STREAM_ABORTED', '%s', Error);
E('ERR_QUIC_STREAM_RESET',
 'The QUIC stream was reset by the peer with error code %d', Error);
E('ERR_QUIC_VERSION_NEGOTIATION_ERROR', 'The QUIC session requires version negotiation', Error);
E('ERR_REQUIRE_ASYNC_MODULE', function(filename, parentFilename) {
 let message = 'require() cannot be used on an ESM ' +
 'graph with top-level await. Use import() instead. To see where the' +
 ' top-level await comes from, use --experimental-print-required-tla.';
 if (parentFilename) {
 message += `\n From ${parentFilename} `;
E('ERR_REQUIRE_ASYNC_MODULE', function(filename, parent, locations) {
 let message = 'require() cannot be used on an ESM graph with top-level await. Use import() instead.';
 const { getOptionValue } = require('internal/options');
 if (!getOptionValue('--experimental-print-required-tla')) {
 message += ' To see where the top-level await comes from, use --experimental-print-required-tla.';
 }
 if (filename) {
 message += `\n Requiring ${filename} `;
 message += `\nRequired module: ${filename}`;
 }
 if (parent) {
 const { getRequireStack } = require('internal/modules/helpers');
 const requireStack = getRequireStack(parent);
 if (requireStack.length > 0) {
 message += '\nRequire stack:\n- ' +
 ArrayPrototypeJoin(requireStack, '\n- ');
 }
 ObjectDefineProperty(this, 'requireStack', {
 __proto__: null,
 enumerable: false,
 configurable: true,
 writable: true,
 value: requireStack,
 });
 }
 if (locations && locations.length > 0) {
 const { urlToFilename } = require('internal/modules/helpers');
 const frames = ArrayPrototypeMap(locations, ({ url, line, column, sourceLine }) =>
 `${urlToFilename(url)}:${line}\n\n${sourceLine}\n${StringPrototypeRepeat(' ', column - 1)}^\n`);
 setArrowMessage(this, ArrayPrototypeJoin(frames, '\n'));
 ObjectDefineProperty(this, 'topLevelAwaitLocations', {
 __proto__: null,
 enumerable: false,
 configurable: true,
 writable: true,
 value: locations,
 });
 }
 return message;
}, Error);
Expand Down

12 changes: 1 addition & 11 deletions
lib/internal/modules/cjs/loader.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -168,6 +168,7 @@ const {
 setHasStartedUserCJSExecution,
 stripBOM,
 toRealPath,
 getRequireStack,
} = require('internal/modules/helpers');
const {
 convertCJSFilenameToURL,
Expand DownExpand Up@@ -1567,17 +1568,6 @@ Module._resolveFilename = function(request, parent, isMain, options) {
 throw err;
};

function getRequireStack(parent) {
 const requireStack = [];
 for (let cursor = parent;
 cursor;
 // TODO(joyeecheung): it makes more sense to use kLastModuleParent here.
 cursor = cursor[kFirstModuleParent]) {
 ArrayPrototypePush(requireStack, cursor.filename || cursor.id);
 }
 return requireStack;
}

function getRequireStackMessage(request, requireStack) {
 let message = `Cannot find module '${request}'`;
 if (requireStack.length > 0) {
Expand Down

14 changes: 9 additions & 5 deletions
lib/internal/modules/esm/loader.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -25,7 +25,6 @@ const { imported_cjs_symbol } = internalBinding('symbols');

const assert = require('internal/assert');
const {
 ERR_REQUIRE_ASYNC_MODULE,
 ERR_REQUIRE_CYCLE_MODULE,
 ERR_REQUIRE_ESM,
 ERR_REQUIRE_ESM_RACE_CONDITION,
Expand DownExpand Up@@ -289,8 +288,8 @@ class ModuleLoader {
 const status = job.module.getStatus();
 debug('Module status', job, status);
 // hasAsyncGraph is available after module been instantiated.
 if (status >= kInstantiated && job.module.hasAsyncGraph) {
throw new ERR_REQUIRE_ASYNC_MODULE(filename, parentFilename);
 if (status >= kInstantiated) {
job.throwIfAsyncGraph(parent);
 }
 if (status === kEvaluated) {
 return { wrap: job.module, namespace: job.module.getNamespace() };
Expand DownExpand Up@@ -318,6 +317,11 @@ class ModuleLoader {
 }
 if (status !== kEvaluating) {
 assert(status === kUninstantiated, `Unexpected module status ${status}`);
 // If we get here, either there's a race where the job is still being instantiated
 // by an in-flight import(), or the cached module previously encountered an
 // instantiation error during a prior load (e.g. due to a mismatched import).
 // TODO(joyeecheung): the current check is too broad. We should attempt to
 // get the potential instantiation error and throw it.
 throw new ERR_REQUIRE_ESM_RACE_CONDITION(filename, parentFilename, false);
 }
 let message = `Cannot require() ES Module ${filename} in a cycle.`;
Expand DownExpand Up@@ -368,8 +372,8 @@ class ModuleLoader {

 // Otherwise the module could be imported before but the evaluation may be already
 // completed (e.g. the require call is lazy) so it's okay. We will return the
 // job and check asynchronicity of the entire graph later, after the
 // graph is instantiated.
 // job and check asynchronicity of the entire graph later, before the
 // graph is evaluated.
 }

 /**
Expand Down
Loading

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Auto-enable theater mode on YouTube\n(function() {\n function tryTheater() {\n var btn = document.querySelector('button[aria-label=\"Theater mode\"], ytd-player #player button[title=\"Theater mode\"]');\n if (btn && !btn.classList.contains('activated')) {\n btn.click();\n }\n }\n \n // Try immediately\n tryTheater();\n \n // Try after navigation (SPA)\n var lastUrl = location.href;\n setInterval(function() {\n if (location.href !== lastUrl) {\n lastUrl = location.href;\n setTimeout(tryTheater, 500);\n }\n }, 1000);\n \n // Also try on player load\n var observer = new MutationObserver(tryTheater);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "YouTube Theater Mode Default");
}
} catch(__e) { console.warn('[Userscript:YouTube Theater Mode Default]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
[v24.x] backport ERR_REQUIRE_ASYNC_MODULE improvements#65125

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 Merged

aduh95
merged 2 commits into

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Aug 13, 2026

+493

−134

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[v24.x] backport ERR_REQUIRE_ASYNC_MODULE improvements
#65125
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d2b02e4

esm: print required top-level await locations without evaluating


joyeecheung Jul 2, 2026
9e39360

esm: improve ERR_REQUIRE_ASYNC_MODULE


joyeecheung Jul 2, 2026

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9 changes: 6 additions & 3 deletions
doc/api/cli.md

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -1177,11 +1177,14 @@
added:
 - v22.0.0
 - v20.17.0
changes:
 - version: REPLACEME
 pr-url: https://github.com/nodejs/node/pull/64154

Check warning
on line 1182
in doc/api/cli.md

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GitHub Actions/ lint-pr-url
pr-url doesn't match the URL of the current PR.
 description: Print the top-level awaits without evaluating the modules.
-->

If the ES module being `require()`'d contains top-level `await`, this flag
allows Node.js to evaluate the module, try to locate the
top-level awaits, and print their location to help users find them.
If the ES module graph cannot be `require()`'d because it contains any top-level `await`,
this flag allows Node.js to locate and print their locations.

### `--experimental-quic`

Expand Down

24 changes: 21 additions & 3 deletions
doc/api/errors.md

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -2765,12 +2765,30 @@

### `ERR_REQUIRE_ASYNC_MODULE`

<!-- YAML
changes:
 - version: REPLACEME
 pr-url: https://github.com/nodejs/node/pull/64260

Check warning
on line 2771
in doc/api/errors.md

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GitHub Actions/ lint-pr-url
pr-url doesn't match the URL of the current PR.
 description: Added the `requireStack` and `topLevelAwaitLocations` properties.
-->

When trying to `require()` an [ES Module][], the module turns out to be asynchronous.
That is, it contains top-level await.

To see where the top-level await is, use
`--experimental-print-required-tla` (this would execute the modules
before looking for the top-level awaits).
When uncaught, the flag `--experimental-print-required-tla` prints
the locations of the top-level awaits in the graph to stderr.

This error has the following additional non-enumerable properties:

* `requireStack` {string\[]} The chain of modules that led to the failing
 `require()`, starting with the module that required the asynchronous module.
* `topLevelAwaitLocations` {Object\[]} The locations of the top-level awaits in
 the graph. Only populated when `--experimental-print-required-tla` is enabled.
 Each entry has the following properties:
 * `url` {string} The URL of the module containing the top-level await.
 * `line` {number} The 1-based line number of the top-level await.
 * `column` {number} The 1-based column number of the top-level await.
 * `sourceLine` {string} The source line containing the top-level await.

<a id="ERR_REQUIRE_CYCLE_MODULE"></a>

Expand Down

7 changes: 3 additions & 4 deletions
doc/api/modules.md

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -317,10 +317,9 @@ graph it `import`s contains top-level `await`,
[`ERR_REQUIRE_ASYNC_MODULE`][] will be thrown. In this case, users should
load the asynchronous module using [`import()`][].

If `--experimental-print-required-tla` is enabled, instead of throwing
`ERR_REQUIRE_ASYNC_MODULE` before evaluation, Node.js will evaluate the
module, try to locate the top-level awaits, and print their location to
help users fix them.
If `--experimental-print-required-tla` is enabled and the error is uncaught,
Node.js will try to locate the top-level `await`s in the `require()`'d module graph
and print the locations in the stderr.

If support for loading ES modules using `require()` results in unexpected
breakage, it can be disabled using `--no-require-module`.
Expand Down

42 changes: 35 additions & 7 deletions
lib/internal/errors.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -48,6 +48,7 @@ const {
 StringPrototypeEndsWith,
 StringPrototypeIncludes,
 StringPrototypeIndexOf,
 StringPrototypeRepeat,
 StringPrototypeSlice,
 StringPrototypeSplit,
 StringPrototypeStartsWith,
Expand DownExpand Up@@ -1692,15 +1693,42 @@ E('ERR_QUIC_STREAM_ABORTED', '%s', Error);
E('ERR_QUIC_STREAM_RESET',
 'The QUIC stream was reset by the peer with error code %d', Error);
E('ERR_QUIC_VERSION_NEGOTIATION_ERROR', 'The QUIC session requires version negotiation', Error);
E('ERR_REQUIRE_ASYNC_MODULE', function(filename, parentFilename) {
 let message = 'require() cannot be used on an ESM ' +
 'graph with top-level await. Use import() instead. To see where the' +
 ' top-level await comes from, use --experimental-print-required-tla.';
 if (parentFilename) {
 message += `\n From ${parentFilename} `;
E('ERR_REQUIRE_ASYNC_MODULE', function(filename, parent, locations) {
 let message = 'require() cannot be used on an ESM graph with top-level await. Use import() instead.';
 const { getOptionValue } = require('internal/options');
 if (!getOptionValue('--experimental-print-required-tla')) {
 message += ' To see where the top-level await comes from, use --experimental-print-required-tla.';
 }
 if (filename) {
 message += `\n Requiring ${filename} `;
 message += `\nRequired module: ${filename}`;
 }
 if (parent) {
 const { getRequireStack } = require('internal/modules/helpers');
 const requireStack = getRequireStack(parent);
 if (requireStack.length > 0) {
 message += '\nRequire stack:\n- ' +
 ArrayPrototypeJoin(requireStack, '\n- ');
 }
 ObjectDefineProperty(this, 'requireStack', {
 __proto__: null,
 enumerable: false,
 configurable: true,
 writable: true,
 value: requireStack,
 });
 }
 if (locations && locations.length > 0) {
 const { urlToFilename } = require('internal/modules/helpers');
 const frames = ArrayPrototypeMap(locations, ({ url, line, column, sourceLine }) =>
 `${urlToFilename(url)}:${line}\n\n${sourceLine}\n${StringPrototypeRepeat(' ', column - 1)}^\n`);
 setArrowMessage(this, ArrayPrototypeJoin(frames, '\n'));
 ObjectDefineProperty(this, 'topLevelAwaitLocations', {
 __proto__: null,
 enumerable: false,
 configurable: true,
 writable: true,
 value: locations,
 });
 }
 return message;
}, Error);
Expand Down

12 changes: 1 addition & 11 deletions
lib/internal/modules/cjs/loader.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -168,6 +168,7 @@ const {
 setHasStartedUserCJSExecution,
 stripBOM,
 toRealPath,
 getRequireStack,
} = require('internal/modules/helpers');
const {
 convertCJSFilenameToURL,
Expand DownExpand Up@@ -1567,17 +1568,6 @@ Module._resolveFilename = function(request, parent, isMain, options) {
 throw err;
};

function getRequireStack(parent) {
 const requireStack = [];
 for (let cursor = parent;
 cursor;
 // TODO(joyeecheung): it makes more sense to use kLastModuleParent here.
 cursor = cursor[kFirstModuleParent]) {
 ArrayPrototypePush(requireStack, cursor.filename || cursor.id);
 }
 return requireStack;
}

function getRequireStackMessage(request, requireStack) {
 let message = `Cannot find module '${request}'`;
 if (requireStack.length > 0) {
Expand Down

14 changes: 9 additions & 5 deletions
lib/internal/modules/esm/loader.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -25,7 +25,6 @@ const { imported_cjs_symbol } = internalBinding('symbols');

const assert = require('internal/assert');
const {
 ERR_REQUIRE_ASYNC_MODULE,
 ERR_REQUIRE_CYCLE_MODULE,
 ERR_REQUIRE_ESM,
 ERR_REQUIRE_ESM_RACE_CONDITION,
Expand DownExpand Up@@ -289,8 +288,8 @@ class ModuleLoader {
 const status = job.module.getStatus();
 debug('Module status', job, status);
 // hasAsyncGraph is available after module been instantiated.
 if (status >= kInstantiated && job.module.hasAsyncGraph) {
throw new ERR_REQUIRE_ASYNC_MODULE(filename, parentFilename);
 if (status >= kInstantiated) {
job.throwIfAsyncGraph(parent);
 }
 if (status === kEvaluated) {
 return { wrap: job.module, namespace: job.module.getNamespace() };
Expand DownExpand Up@@ -318,6 +317,11 @@ class ModuleLoader {
 }
 if (status !== kEvaluating) {
 assert(status === kUninstantiated, `Unexpected module status ${status}`);
 // If we get here, either there's a race where the job is still being instantiated
 // by an in-flight import(), or the cached module previously encountered an
 // instantiation error during a prior load (e.g. due to a mismatched import).
 // TODO(joyeecheung): the current check is too broad. We should attempt to
 // get the potential instantiation error and throw it.
 throw new ERR_REQUIRE_ESM_RACE_CONDITION(filename, parentFilename, false);
 }
 let message = `Cannot require() ES Module ${filename} in a cycle.`;
Expand DownExpand Up@@ -368,8 +372,8 @@ class ModuleLoader {

 // Otherwise the module could be imported before but the evaluation may be already
 // completed (e.g. the require call is lazy) so it's okay. We will return the
 // job and check asynchronicity of the entire graph later, after the
 // graph is instantiated.
 // job and check asynchronicity of the entire graph later, before the
 // graph is evaluated.
 }

 /**
Expand Down
Loading

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Remove or un-stick sticky/fixed headers that block content\n(function() {\n function unstick() {\n document.querySelectorAll('header, nav, [role=\"banner\"], .header, .navbar, .sticky, .fixed-top, [style*=\"position: fixed\"], [style*=\"position:sticky\"]').forEach(function(el) {\n if (el.style.position === 'fixed' || el.style.position === 'sticky' || \n getComputedStyle(el).position === 'fixed' || getComputedStyle(el).position === 'sticky') {\n el.style.position = 'static';\n el.style.top = 'auto';\n el.style.zIndex = 'auto';\n }\n });\n }\n \n unstick();\n \n var observer = new MutationObserver(unstick);\n observer.observe(document.body, { childList: true, subtree: true, attributes: true, attributeFilter: ['style', 'class'] });\n})();", "Kill Sticky Headers");
}
} catch(__e) { console.warn('[Userscript:Kill Sticky Headers]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
[v24.x] backport ERR_REQUIRE_ASYNC_MODULE improvements#65125

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 Merged

aduh95
merged 2 commits into

from

Aug 13, 2026

+493

−134

 Merged


[v24.x] backport ERR_REQUIRE_ASYNC_MODULE improvements
#65125
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d2b02e4

esm: print required top-level await locations without evaluating


joyeecheung Jul 2, 2026
9e39360

esm: improve ERR_REQUIRE_ASYNC_MODULE


joyeecheung Jul 2, 2026

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9 changes: 6 additions & 3 deletions
doc/api/cli.md

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -1177,11 +1177,14 @@
added:
 - v22.0.0
 - v20.17.0
changes:
 - version: REPLACEME
 pr-url: https://github.com/nodejs/node/pull/64154

Check warning
on line 1182
in doc/api/cli.md

View workflow job for this annotation
GitHub Actions/ lint-pr-url
pr-url doesn't match the URL of the current PR.
 description: Print the top-level awaits without evaluating the modules.
-->

If the ES module being `require()`'d contains top-level `await`, this flag
allows Node.js to evaluate the module, try to locate the
top-level awaits, and print their location to help users find them.
If the ES module graph cannot be `require()`'d because it contains any top-level `await`,
this flag allows Node.js to locate and print their locations.

### `--experimental-quic`

Expand Down

24 changes: 21 additions & 3 deletions
doc/api/errors.md

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -2765,12 +2765,30 @@

### `ERR_REQUIRE_ASYNC_MODULE`

<!-- YAML
changes:
 - version: REPLACEME
 pr-url: https://github.com/nodejs/node/pull/64260

Check warning
on line 2771
in doc/api/errors.md

View workflow job for this annotation
GitHub Actions/ lint-pr-url
pr-url doesn't match the URL of the current PR.
 description: Added the `requireStack` and `topLevelAwaitLocations` properties.
-->

When trying to `require()` an [ES Module][], the module turns out to be asynchronous.
That is, it contains top-level await.

To see where the top-level await is, use
`--experimental-print-required-tla` (this would execute the modules
before looking for the top-level awaits).
When uncaught, the flag `--experimental-print-required-tla` prints
the locations of the top-level awaits in the graph to stderr.

This error has the following additional non-enumerable properties:

* `requireStack` {string\[]} The chain of modules that led to the failing
 `require()`, starting with the module that required the asynchronous module.
* `topLevelAwaitLocations` {Object\[]} The locations of the top-level awaits in
 the graph. Only populated when `--experimental-print-required-tla` is enabled.
 Each entry has the following properties:
 * `url` {string} The URL of the module containing the top-level await.
 * `line` {number} The 1-based line number of the top-level await.
 * `column` {number} The 1-based column number of the top-level await.
 * `sourceLine` {string} The source line containing the top-level await.

<a id="ERR_REQUIRE_CYCLE_MODULE"></a>

Expand Down

7 changes: 3 additions & 4 deletions
doc/api/modules.md

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -317,10 +317,9 @@ graph it `import`s contains top-level `await`,
[`ERR_REQUIRE_ASYNC_MODULE`][] will be thrown. In this case, users should
load the asynchronous module using [`import()`][].

If `--experimental-print-required-tla` is enabled, instead of throwing
`ERR_REQUIRE_ASYNC_MODULE` before evaluation, Node.js will evaluate the
module, try to locate the top-level awaits, and print their location to
help users fix them.
If `--experimental-print-required-tla` is enabled and the error is uncaught,
Node.js will try to locate the top-level `await`s in the `require()`'d module graph
and print the locations in the stderr.

If support for loading ES modules using `require()` results in unexpected
breakage, it can be disabled using `--no-require-module`.
Expand Down

42 changes: 35 additions & 7 deletions
lib/internal/errors.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -48,6 +48,7 @@ const {
 StringPrototypeEndsWith,
 StringPrototypeIncludes,
 StringPrototypeIndexOf,
 StringPrototypeRepeat,
 StringPrototypeSlice,
 StringPrototypeSplit,
 StringPrototypeStartsWith,
Expand DownExpand Up@@ -1692,15 +1693,42 @@ E('ERR_QUIC_STREAM_ABORTED', '%s', Error);
E('ERR_QUIC_STREAM_RESET',
 'The QUIC stream was reset by the peer with error code %d', Error);
E('ERR_QUIC_VERSION_NEGOTIATION_ERROR', 'The QUIC session requires version negotiation', Error);
E('ERR_REQUIRE_ASYNC_MODULE', function(filename, parentFilename) {
 let message = 'require() cannot be used on an ESM ' +
 'graph with top-level await. Use import() instead. To see where the' +
 ' top-level await comes from, use --experimental-print-required-tla.';
 if (parentFilename) {
 message += `\n From ${parentFilename} `;
E('ERR_REQUIRE_ASYNC_MODULE', function(filename, parent, locations) {
 let message = 'require() cannot be used on an ESM graph with top-level await. Use import() instead.';
 const { getOptionValue } = require('internal/options');
 if (!getOptionValue('--experimental-print-required-tla')) {
 message += ' To see where the top-level await comes from, use --experimental-print-required-tla.';
 }
 if (filename) {
 message += `\n Requiring ${filename} `;
 message += `\nRequired module: ${filename}`;
 }
 if (parent) {
 const { getRequireStack } = require('internal/modules/helpers');
 const requireStack = getRequireStack(parent);
 if (requireStack.length > 0) {
 message += '\nRequire stack:\n- ' +
 ArrayPrototypeJoin(requireStack, '\n- ');
 }
 ObjectDefineProperty(this, 'requireStack', {
 __proto__: null,
 enumerable: false,
 configurable: true,
 writable: true,
 value: requireStack,
 });
 }
 if (locations && locations.length > 0) {
 const { urlToFilename } = require('internal/modules/helpers');
 const frames = ArrayPrototypeMap(locations, ({ url, line, column, sourceLine }) =>
 `${urlToFilename(url)}:${line}\n\n${sourceLine}\n${StringPrototypeRepeat(' ', column - 1)}^\n`);
 setArrowMessage(this, ArrayPrototypeJoin(frames, '\n'));
 ObjectDefineProperty(this, 'topLevelAwaitLocations', {
 __proto__: null,
 enumerable: false,
 configurable: true,
 writable: true,
 value: locations,
 });
 }
 return message;
}, Error);
Expand Down

12 changes: 1 addition & 11 deletions
lib/internal/modules/cjs/loader.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -168,6 +168,7 @@ const {
 setHasStartedUserCJSExecution,
 stripBOM,
 toRealPath,
 getRequireStack,
} = require('internal/modules/helpers');
const {
 convertCJSFilenameToURL,
Expand DownExpand Up@@ -1567,17 +1568,6 @@ Module._resolveFilename = function(request, parent, isMain, options) {
 throw err;
};

function getRequireStack(parent) {
 const requireStack = [];
 for (let cursor = parent;
 cursor;
 // TODO(joyeecheung): it makes more sense to use kLastModuleParent here.
 cursor = cursor[kFirstModuleParent]) {
 ArrayPrototypePush(requireStack, cursor.filename || cursor.id);
 }
 return requireStack;
}

function getRequireStackMessage(request, requireStack) {
 let message = `Cannot find module '${request}'`;
 if (requireStack.length > 0) {
Expand Down

14 changes: 9 additions & 5 deletions
lib/internal/modules/esm/loader.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -25,7 +25,6 @@ const { imported_cjs_symbol } = internalBinding('symbols');

const assert = require('internal/assert');
const {
 ERR_REQUIRE_ASYNC_MODULE,
 ERR_REQUIRE_CYCLE_MODULE,
 ERR_REQUIRE_ESM,
 ERR_REQUIRE_ESM_RACE_CONDITION,
Expand DownExpand Up@@ -289,8 +288,8 @@ class ModuleLoader {
 const status = job.module.getStatus();
 debug('Module status', job, status);
 // hasAsyncGraph is available after module been instantiated.
 if (status >= kInstantiated && job.module.hasAsyncGraph) {
throw new ERR_REQUIRE_ASYNC_MODULE(filename, parentFilename);
 if (status >= kInstantiated) {
job.throwIfAsyncGraph(parent);
 }
 if (status === kEvaluated) {
 return { wrap: job.module, namespace: job.module.getNamespace() };
Expand DownExpand Up@@ -318,6 +317,11 @@ class ModuleLoader {
 }
 if (status !== kEvaluating) {
 assert(status === kUninstantiated, `Unexpected module status ${status}`);
 // If we get here, either there's a race where the job is still being instantiated
 // by an in-flight import(), or the cached module previously encountered an
 // instantiation error during a prior load (e.g. due to a mismatched import).
 // TODO(joyeecheung): the current check is too broad. We should attempt to
 // get the potential instantiation error and throw it.
 throw new ERR_REQUIRE_ESM_RACE_CONDITION(filename, parentFilename, false);
 }
 let message = `Cannot require() ES Module ${filename} in a cycle.`;
Expand DownExpand Up@@ -368,8 +372,8 @@ class ModuleLoader {

 // Otherwise the module could be imported before but the evaluation may be already
 // completed (e.g. the require call is lazy) so it's okay. We will return the
 // job and check asynchronicity of the entire graph later, after the
 // graph is instantiated.
 // job and check asynchronicity of the entire graph later, before the
 // graph is evaluated.
 }

 /**
Expand Down
Loading

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

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[v24.x] backport ERR_REQUIRE_ASYNC_MODULE improvements#65125

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 Merged

aduh95
merged 2 commits into

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Aug 13, 2026

+493

−134

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[v24.x] backport ERR_REQUIRE_ASYNC_MODULE improvements
#65125
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d2b02e4

esm: print required top-level await locations without evaluating


joyeecheung Jul 2, 2026
9e39360

esm: improve ERR_REQUIRE_ASYNC_MODULE


joyeecheung Jul 2, 2026

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9 changes: 6 additions & 3 deletions
doc/api/cli.md

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Original file line numberDiff line numberDiff line change
Expand Up@@ -1177,11 +1177,14 @@
added:
 - v22.0.0
 - v20.17.0
changes:
 - version: REPLACEME
 pr-url: https://github.com/nodejs/node/pull/64154

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on line 1182
in doc/api/cli.md

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 description: Print the top-level awaits without evaluating the modules.
-->

If the ES module being `require()`'d contains top-level `await`, this flag
allows Node.js to evaluate the module, try to locate the
top-level awaits, and print their location to help users find them.
If the ES module graph cannot be `require()`'d because it contains any top-level `await`,
this flag allows Node.js to locate and print their locations.

### `--experimental-quic`

Expand Down

24 changes: 21 additions & 3 deletions
doc/api/errors.md

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Original file line numberDiff line numberDiff line change
Expand Up@@ -2765,12 +2765,30 @@

### `ERR_REQUIRE_ASYNC_MODULE`

<!-- YAML
changes:
 - version: REPLACEME
 pr-url: https://github.com/nodejs/node/pull/64260

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 description: Added the `requireStack` and `topLevelAwaitLocations` properties.
-->

When trying to `require()` an [ES Module][], the module turns out to be asynchronous.
That is, it contains top-level await.

To see where the top-level await is, use
`--experimental-print-required-tla` (this would execute the modules
before looking for the top-level awaits).
When uncaught, the flag `--experimental-print-required-tla` prints
the locations of the top-level awaits in the graph to stderr.

This error has the following additional non-enumerable properties:

* `requireStack` {string\[]} The chain of modules that led to the failing
 `require()`, starting with the module that required the asynchronous module.
* `topLevelAwaitLocations` {Object\[]} The locations of the top-level awaits in
 the graph. Only populated when `--experimental-print-required-tla` is enabled.
 Each entry has the following properties:
 * `url` {string} The URL of the module containing the top-level await.
 * `line` {number} The 1-based line number of the top-level await.
 * `column` {number} The 1-based column number of the top-level await.
 * `sourceLine` {string} The source line containing the top-level await.

<a id="ERR_REQUIRE_CYCLE_MODULE"></a>

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7 changes: 3 additions & 4 deletions
doc/api/modules.md

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Original file line numberDiff line numberDiff line change
Expand Up@@ -317,10 +317,9 @@ graph it `import`s contains top-level `await`,
[`ERR_REQUIRE_ASYNC_MODULE`][] will be thrown. In this case, users should
load the asynchronous module using [`import()`][].

If `--experimental-print-required-tla` is enabled, instead of throwing
`ERR_REQUIRE_ASYNC_MODULE` before evaluation, Node.js will evaluate the
module, try to locate the top-level awaits, and print their location to
help users fix them.
If `--experimental-print-required-tla` is enabled and the error is uncaught,
Node.js will try to locate the top-level `await`s in the `require()`'d module graph
and print the locations in the stderr.

If support for loading ES modules using `require()` results in unexpected
breakage, it can be disabled using `--no-require-module`.
Expand Down

42 changes: 35 additions & 7 deletions
lib/internal/errors.js

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Original file line numberDiff line numberDiff line change
Expand Up@@ -48,6 +48,7 @@ const {
 StringPrototypeEndsWith,
 StringPrototypeIncludes,
 StringPrototypeIndexOf,
 StringPrototypeRepeat,
 StringPrototypeSlice,
 StringPrototypeSplit,
 StringPrototypeStartsWith,
Expand DownExpand Up@@ -1692,15 +1693,42 @@ E('ERR_QUIC_STREAM_ABORTED', '%s', Error);
E('ERR_QUIC_STREAM_RESET',
 'The QUIC stream was reset by the peer with error code %d', Error);
E('ERR_QUIC_VERSION_NEGOTIATION_ERROR', 'The QUIC session requires version negotiation', Error);
E('ERR_REQUIRE_ASYNC_MODULE', function(filename, parentFilename) {
 let message = 'require() cannot be used on an ESM ' +
 'graph with top-level await. Use import() instead. To see where the' +
 ' top-level await comes from, use --experimental-print-required-tla.';
 if (parentFilename) {
 message += `\n From ${parentFilename} `;
E('ERR_REQUIRE_ASYNC_MODULE', function(filename, parent, locations) {
 let message = 'require() cannot be used on an ESM graph with top-level await. Use import() instead.';
 const { getOptionValue } = require('internal/options');
 if (!getOptionValue('--experimental-print-required-tla')) {
 message += ' To see where the top-level await comes from, use --experimental-print-required-tla.';
 }
 if (filename) {
 message += `\n Requiring ${filename} `;
 message += `\nRequired module: ${filename}`;
 }
 if (parent) {
 const { getRequireStack } = require('internal/modules/helpers');
 const requireStack = getRequireStack(parent);
 if (requireStack.length > 0) {
 message += '\nRequire stack:\n- ' +
 ArrayPrototypeJoin(requireStack, '\n- ');
 }
 ObjectDefineProperty(this, 'requireStack', {
 __proto__: null,
 enumerable: false,
 configurable: true,
 writable: true,
 value: requireStack,
 });
 }
 if (locations && locations.length > 0) {
 const { urlToFilename } = require('internal/modules/helpers');
 const frames = ArrayPrototypeMap(locations, ({ url, line, column, sourceLine }) =>
 `${urlToFilename(url)}:${line}\n\n${sourceLine}\n${StringPrototypeRepeat(' ', column - 1)}^\n`);
 setArrowMessage(this, ArrayPrototypeJoin(frames, '\n'));
 ObjectDefineProperty(this, 'topLevelAwaitLocations', {
 __proto__: null,
 enumerable: false,
 configurable: true,
 writable: true,
 value: locations,
 });
 }
 return message;
}, Error);
Expand Down

12 changes: 1 addition & 11 deletions
lib/internal/modules/cjs/loader.js

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Original file line numberDiff line numberDiff line change
Expand Up@@ -168,6 +168,7 @@ const {
 setHasStartedUserCJSExecution,
 stripBOM,
 toRealPath,
 getRequireStack,
} = require('internal/modules/helpers');
const {
 convertCJSFilenameToURL,
Expand DownExpand Up@@ -1567,17 +1568,6 @@ Module._resolveFilename = function(request, parent, isMain, options) {
 throw err;
};

function getRequireStack(parent) {
 const requireStack = [];
 for (let cursor = parent;
 cursor;
 // TODO(joyeecheung): it makes more sense to use kLastModuleParent here.
 cursor = cursor[kFirstModuleParent]) {
 ArrayPrototypePush(requireStack, cursor.filename || cursor.id);
 }
 return requireStack;
}

function getRequireStackMessage(request, requireStack) {
 let message = `Cannot find module '${request}'`;
 if (requireStack.length > 0) {
Expand Down

14 changes: 9 additions & 5 deletions
lib/internal/modules/esm/loader.js

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Original file line numberDiff line numberDiff line change
Expand Up@@ -25,7 +25,6 @@ const { imported_cjs_symbol } = internalBinding('symbols');

const assert = require('internal/assert');
const {
 ERR_REQUIRE_ASYNC_MODULE,
 ERR_REQUIRE_CYCLE_MODULE,
 ERR_REQUIRE_ESM,
 ERR_REQUIRE_ESM_RACE_CONDITION,
Expand DownExpand Up@@ -289,8 +288,8 @@ class ModuleLoader {
 const status = job.module.getStatus();
 debug('Module status', job, status);
 // hasAsyncGraph is available after module been instantiated.
 if (status >= kInstantiated && job.module.hasAsyncGraph) {
throw new ERR_REQUIRE_ASYNC_MODULE(filename, parentFilename);
 if (status >= kInstantiated) {
job.throwIfAsyncGraph(parent);
 }
 if (status === kEvaluated) {
 return { wrap: job.module, namespace: job.module.getNamespace() };
Expand DownExpand Up@@ -318,6 +317,11 @@ class ModuleLoader {
 }
 if (status !== kEvaluating) {
 assert(status === kUninstantiated, `Unexpected module status ${status}`);
 // If we get here, either there's a race where the job is still being instantiated
 // by an in-flight import(), or the cached module previously encountered an
 // instantiation error during a prior load (e.g. due to a mismatched import).
 // TODO(joyeecheung): the current check is too broad. We should attempt to
 // get the potential instantiation error and throw it.
 throw new ERR_REQUIRE_ESM_RACE_CONDITION(filename, parentFilename, false);
 }
 let message = `Cannot require() ES Module ${filename} in a cycle.`;
Expand DownExpand Up@@ -368,8 +372,8 @@ class ModuleLoader {

 // Otherwise the module could be imported before but the evaluation may be already
 // completed (e.g. the require call is lazy) so it's okay. We will return the
 // job and check asynchronicity of the entire graph later, after the
 // graph is instantiated.
 // job and check asynchronicity of the entire graph later, before the
 // graph is evaluated.
 }

 /**
Expand Down
Loading