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Merged
nodejs-github-bot merged 1 commit into from
Jun 23, 2026
+51 −15
Merged

test_runner: improve coverage failure diagnostics #64050

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21 changes: 20 additions & 1 deletion lib/internal/test_runner/coverage.js
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Original file line numberDiff line numberDiff line change
Expand Up@@ -33,6 +33,7 @@ const { fileURLToPath, URL } = require('internal/url');
const{ kMappings, SourceMap }=require('internal/source_map/source_map');
const{
codes: {
ERR_OPERATION_FAILED,
ERR_SOURCE_MAP_CORRUPT,
ERR_SOURCE_MAP_MISSING_SOURCE,
},
Expand DownExpand Up@@ -402,7 +403,7 @@ class TestCoverage {
}

constcoverageFile=join(this.coverageDirectory,entry.name);
constcoverage=JSONParse(readFileSync(coverageFile,'utf8'));
constcoverage=readCoverageFile(coverageFile);
this.mergeCoverage(result,this.mapCoverageWithSourceMap(coverage));
}

Expand DownExpand Up@@ -587,6 +588,24 @@ class TestCoverage {
}
}

functionreadCoverageFile(coverageFile){
constrawCoverage=readFileSync(coverageFile,'utf8');

if(rawCoverage.length===0){
thrownewERR_OPERATION_FAILED(`coverage file is empty: ${coverageFile}`);
}

try{
returnJSONParse(rawCoverage);
}catch(err){
consterror=newERR_OPERATION_FAILED(
`failed to parse coverage file ${coverageFile}: ${err.message}`,
);
error.cause=err;
throwerror;
}
}

functiontoPercentage(covered,total){
returntotal===0 ? 100 : (covered/total)*100;
}
Expand Down
45 changes: 31 additions & 14 deletions test/parallel/test-runner-coverage.js
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Original file line numberDiff line numberDiff line change
Expand Up@@ -77,6 +77,22 @@ function getSpecCoverageFixtureReport() {
return report;
}

function formatSpawnSyncResult(result) {
return [
`status: ${result.status}`,
`signal: ${result.signal}`,
`stdout:\n${result.stdout}`,
`stderr:\n${result.stderr}`,
].join('\n');
}

function assertIncludesReport(result, report) {
assert(
result.stdout.toString().includes(report),
formatSpawnSyncResult(result),
);
}

test('test coverage report', async (t) => {
await t.test('handles the inspector not being available', (t) => {
if (process.features.inspector) {
Expand DownExpand Up@@ -111,7 +127,7 @@ test('test tap coverage reporter', skipIfNoInspector, async (t) => {
const options = { env: { ...process.env, NODE_V8_COVERAGE: tmpdir.path } };
const result = spawnSync(process.execPath, args, options);
const report = getTapCoverageFixtureReport();
assert(result.stdout.toString().includes(report));
assertIncludesReport(result, report);
assert.strictEqual(result.stderr.toString(), '');
assert.strictEqual(result.status, 0);
assert(findCoverageFileForPid(result.pid));
Expand All@@ -129,7 +145,7 @@ test('test tap coverage reporter', skipIfNoInspector, async (t) => {
const result = spawnSync(process.execPath, args);
const report = getTapCoverageFixtureReport();

assert(result.stdout.toString().includes(report));
assertIncludesReport(result, report);
assert.strictEqual(result.stderr.toString(), '');
assert.strictEqual(result.status, 0);
assert(!findCoverageFileForPid(result.pid));
Expand All@@ -149,7 +165,7 @@ test('test spec coverage reporter', skipIfNoInspector, async (t) => {
const result = spawnSync(process.execPath, args, options);
const report = getSpecCoverageFixtureReport();

assert(result.stdout.toString().includes(report));
assertIncludesReport(result, report);
assert.strictEqual(result.stderr.toString(), '');
assert.strictEqual(result.status, 0);
assert(findCoverageFileForPid(result.pid));
Expand All@@ -166,7 +182,7 @@ test('test spec coverage reporter', skipIfNoInspector, async (t) => {
const result = spawnSync(process.execPath, args);
const report = getSpecCoverageFixtureReport();

assert(result.stdout.toString().includes(report));
assertIncludesReport(result, report);
assert.strictEqual(result.stderr.toString(), '');
assert.strictEqual(result.status, 0);
assert(!findCoverageFileForPid(result.pid));
Expand All@@ -187,7 +203,7 @@ test('single process coverage is the same with --test', skipIfNoInspector, () =>
const report = getTapCoverageFixtureReport();

assert.strictEqual(result.stderr.toString(), '');
assert(result.stdout.toString().includes(report));
assertIncludesReport(result, report);
assert.strictEqual(result.status, 0);
assert(!findCoverageFileForPid(result.pid));
});
Expand DownExpand Up@@ -226,7 +242,7 @@ test('coverage is combined for multiple processes', skipIfNoInspector, () => {
});

assert.strictEqual(result.stderr.toString(), '');
assert(result.stdout.toString().includes(report));
assertIncludesReport(result, report);
assert.strictEqual(result.status, 0);
});

Expand DownExpand Up@@ -268,7 +284,7 @@ test.skip('coverage works with isolation=none', skipIfNoInspector, common.mustCa
});

assert.strictEqual(result.stderr.toString(), '');
assert(result.stdout.toString().includes(report));
assertIncludesReport(result, report);
assert.strictEqual(result.status, 0);
}, 0));

Expand All@@ -285,6 +301,7 @@ test('coverage reports on lines, functions, and branches', skipIfNoInspector, as
]);
assert.strictEqual(child.stderr.toString(), '');
const stdout = child.stdout.toString();
assert.notStrictEqual(stdout, '', formatSpawnSyncResult(child));
const coverage = JSON.parse(stdout);

await t.test('does not include node_modules', () => {
Expand DownExpand Up@@ -366,7 +383,7 @@ test('coverage with ESM hook - source irrelevant', skipIfNoInspector, () => {
const result = spawnSync(process.execPath, args, { cwd: fixture });

assert.strictEqual(result.stderr.toString(), '');
assert(result.stdout.toString().includes(report));
assertIncludesReport(result, report);
assert.strictEqual(result.status, 0);
});

Expand DownExpand Up@@ -401,7 +418,7 @@ test('coverage with ESM hook - source transpiled', skipIfNoInspector, () => {
const result = spawnSync(process.execPath, args, { cwd: fixture });

assert.strictEqual(result.stderr.toString(), '');
assert(result.stdout.toString().includes(report));
assertIncludesReport(result, report);
assert.strictEqual(result.status, 0);
});

Expand DownExpand Up@@ -435,7 +452,7 @@ test('coverage with excluded files', skipIfNoInspector, () => {
return report.replaceAll('/', '\\');
}

assert(result.stdout.toString().includes(report));
assertIncludesReport(result, report);
assert.strictEqual(result.status, 0);
assert(!findCoverageFileForPid(result.pid));
});
Expand DownExpand Up@@ -472,7 +489,7 @@ test('coverage with included files', skipIfNoInspector, () => {
return report.replaceAll('/', '\\');
}

assert(result.stdout.toString().includes(report));
assertIncludesReport(result, report);
assert.strictEqual(result.status, 0);
assert(!findCoverageFileForPid(result.pid));
});
Expand DownExpand Up@@ -506,7 +523,7 @@ test('coverage with included and excluded files', skipIfNoInspector, () => {
return report.replaceAll('/', '\\');
}

assert(result.stdout.toString().includes(report));
assertIncludesReport(result, report);
assert.strictEqual(result.status, 0);
assert(!findCoverageFileForPid(result.pid));
});
Expand DownExpand Up@@ -547,7 +564,7 @@ test('correctly prints the coverage report of files contained in parent director
});

assert.strictEqual(result.stderr.toString(), '');
assert(result.stdout.toString().includes(report));
assertIncludesReport(result, report);
assert.strictEqual(result.status, 0);
});

Expand All@@ -564,5 +581,5 @@ test('coverage with directory and file named "file"', skipIfNoInspector, () => {

assert.strictEqual(result.stderr.toString(), '');
assert.strictEqual(result.status, 0);
assert(result.stdout.toString().includes('start of coverage report'));
assertIncludesReport(result, 'start of coverage report');
});
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