fix(github): tolerate test:fail events without a details.error (#175)

MoLow · web-flow · commit 3c2da3439824 · 2026-04-19T18:50:54.000+03:00
Node can emit `test:fail` where `details.error` is null — for example when
a hook re-run resets `this.error` before reporting (see
`lib/internal/test_runner/test.js`). The previous code dereferenced
`error.code` unconditionally on line 90, throwing
`TypeError: Cannot read properties of null (reading 'code')`.

Because `transformEvent` runs inside a Transform stream (`SpecReporter._transform`),
the synchronous throw surfaces as an unhandled `'error'` event on the stream,
which crashes the whole `node --test` process. Any reporters wired alongside
it (including the internal `rerun` reporter used by `--test-rerun-failures`)
lose their chance to flush, leaving truncated output files.

Skip annotation when there is no error object, matching the existing behavior
for `subtestsFailed` wrappers.
diff --git a/packages/github/index.js b/packages/github/index.js
@@ -82,9 +82,9 @@ function transformEvent(event) {
       return new Command('debug', {}, `completed running ${event.data.name}`).toString();
     case 'test:fail': {
       const error = event.data.details?.error;
-      if (error?.code === 'ERR_TEST_FAILURE' && error?.failureType === 'subtestsFailed') {
-        // This means the failed subtests are already reported
-        // no need to re-annotate the file itself
+      if (!error || (error.code === 'ERR_TEST_FAILURE' && error.failureType === 'subtestsFailed')) {
+        // Either no error object on the event, or failed subtests are already
+        // reported — no need to re-annotate the file itself.
         break;
       }
       const err = error.code === 'ERR_TEST_FAILURE' ? error.cause : error;
diff --git a/packages/github/tests/index.test.js b/packages/github/tests/index.test.js
@@ -1,12 +1,14 @@
 'use strict';
 
 const { test, describe, beforeEach } = require('node:test');
+const assert = require('node:assert');
 const { spawnSync } = require('child_process');
 const { tmpdir } = require('os');
 const { join } = require('path');
 const path = require('path');
 const { readFileSync, writeFileSync } = require('fs');
 const { Snap, nodeMajor } = require('../../../tests/utils');
+const { transformEvent } = require('../index');
 
 const snapshot = Snap(`${__filename}.${nodeMajor}`);
 const GITHUB_STEP_SUMMARY = join(tmpdir(), 'github-actions-test-reporter');
@@ -46,4 +48,30 @@ describe('github reporter', () => {
     const silentChild = spawnSync(process.execPath, ['--test-reporter', './index.js', '../../tests/example'], { env: { } });
     await snapshot(silentChild);
   });
+
+  test('transformEvent tolerates test:fail with no error object', () => {
+    // Node can emit test:fail where details.error is null (e.g. hook re-runs
+    // that reset this.error — see lib/internal/test_runner/test.js). The
+    // reporter must not throw on such events, otherwise the unhandled 'error'
+    // on the Transform stream crashes the whole test runner.
+    assert.doesNotThrow(() => transformEvent({
+      type: 'test:fail',
+      data: {
+        name: 'no error',
+        details: { error: null },
+        file: 'x.js',
+        line: 1,
+        column: 1,
+      },
+    }));
+    assert.doesNotThrow(() => transformEvent({
+      type: 'test:fail',
+      data: {
+        name: 'no details',
+        file: 'x.js',
+        line: 1,
+        column: 1,
+      },
+    }));
+  });
 });
