From 65d4ba819a4ca95d7a76a83f41643cbf12c5b3c9 Mon Sep 17 00:00:00 2001
From: Jaromir Obr <jobr@spork.tech>
Date: Wed, 21 Oct 2026 15:10:22 +0200
Subject: [PATCH] fix(junitReporter): group run-workers tests into one
 testsuite per suite

Under run-workers each test arrives in the main process with its own
deserialized parent, so grouping by object identity put every test into
its own <testsuite>. Group by suite title and file instead, and keep the
suite file when serializing tests so worker suite hook failures land in
the same <testsuite> as their tests.

Fixes #5760

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---
 lib/mocha/test.js               |  1 +
 lib/plugin/junitReporter.js     | 12 ++--------
 test/unit/junitReporter_test.js | 39 +++++++++++++++++++++++++++++++++
 3 files changed, 42 insertions(+), 10 deletions(-)

diff --git a/lib/mocha/test.js b/lib/mocha/test.js
index f85c070ef..cf012fb0b 100644
--- a/lib/mocha/test.js
+++ b/lib/mocha/test.js
@@ -106,6 +106,7 @@ function serializeTest(test, error = null) {
   const parent = {}
   if (test.parent) {
     parent.title = test.parent.title
+    parent.file = test.parent.file
   }
 
   if (test.opts) {
diff --git a/lib/plugin/junitReporter.js b/lib/plugin/junitReporter.js
index 2e84d2076..f6fcbf57d 100644
--- a/lib/plugin/junitReporter.js
+++ b/lib/plugin/junitReporter.js
@@ -67,10 +67,6 @@ export default function (config = {}) {
 
   let written = false
   const hookFailures = []
-  // groupBySuite() (below) groups by object identity, not by value — reused
-  // across BeforeSuite/AfterSuite failures from the same worker-forwarded
-  // suite so they land in one <testsuite>, not one per failure.
-  const workerSuiteByKey = new Map()
 
   event.dispatcher.on(event.hook.failed, hook => {
     if (!hook || !['BeforeSuite', 'AfterSuite'].includes(hook.hookName)) return
@@ -84,11 +80,7 @@ export default function (config = {}) {
     // groups under its real suite instead of the "Tests" fallback.
     let suite = runnable && runnable.parent
     if (!suite && hook.suiteTitle) {
-      const key = `${hook.suiteTitle} ${hook.suiteFile || ''}`
-      if (!workerSuiteByKey.has(key)) {
-        workerSuiteByKey.set(key, { title: hook.suiteTitle, file: hook.suiteFile, tags: hook.suiteTags })
-      }
-      suite = workerSuiteByKey.get(key)
+      suite = { title: hook.suiteTitle, file: hook.suiteFile, tags: hook.suiteTags }
     }
     hookFailures.push({
       title: hook.title || `${hook.hookName} hook failed`,
@@ -296,7 +288,7 @@ function groupBySuite(tests) {
   const groups = []
   const byKey = new Map()
   for (const test of tests) {
-    const key = test.parent || test
+    const key = test.parent ? `${test.parent.title}\0${test.parent.file || test.file || ''}` : test
     if (!byKey.has(key)) {
       const list = []
       byKey.set(key, list)
diff --git a/test/unit/junitReporter_test.js b/test/unit/junitReporter_test.js
index feef9efbc..b4a56625a 100644
--- a/test/unit/junitReporter_test.js
+++ b/test/unit/junitReporter_test.js
@@ -231,6 +231,45 @@ describe('JUnit Reporter Plugin', () => {
     expect(tagsProp.$.value).to.equal('@smoke')
   })
 
+  it('groups worker tests with separately deserialized parents into one testsuite per suite', async () => {
+    junitReporter({})
+
+    const workerTest = (suiteTitle, title) => ({ title, state: 'passed', duration: 10, parent: { title: suiteTitle }, meta: {}, steps: [] })
+
+    event.dispatcher.emit(event.workers.result, {
+      tests: [workerTest('SuiteB', 'scenario 1'), workerTest('SuiteB', 'scenario 2'), workerTest('SuiteA', 'scenario 1'), workerTest('SuiteA', 'scenario 2')],
+      stats: { start: new Date(), passes: 4, failures: 0, pending: 0, tests: 4 },
+    })
+
+    const parsed = await parseReport(tmpDir)
+    const suites = parsed.testsuites.testsuite
+    expect(suites.map(s => s.$.name)).to.deep.equal(['SuiteB', 'SuiteA'])
+    expect(suites.map(s => s.$.tests)).to.deep.equal(['2', '2'])
+  })
+
+  it('groups a worker suite hook failure with the tests of the same suite', async () => {
+    junitReporter({})
+
+    event.dispatcher.emit(event.hook.failed, {
+      hookName: 'AfterSuite',
+      title: '"after all" hook: AfterSuite for "scenario 1"',
+      suiteTitle: 'SuiteC',
+      suiteFile: '/tests/suite_c_test.js',
+      error: { message: 'AfterSuite failed' },
+    })
+
+    event.dispatcher.emit(event.workers.result, {
+      tests: [{ title: 'scenario 1', state: 'passed', duration: 10, parent: { title: 'SuiteC', file: '/tests/suite_c_test.js' }, meta: {}, steps: [] }],
+      stats: { start: new Date(), passes: 1, failures: 0, pending: 0, tests: 1 },
+    })
+
+    const parsed = await parseReport(tmpDir)
+    const suites = parsed.testsuites.testsuite
+    expect(suites).to.have.length(1)
+    expect(suites[0].$.name).to.equal('SuiteC')
+    expect(suites[0].$.tests).to.equal('2')
+  })
+
   it('adds suite hook failures forwarded from workers as failed testcases', async () => {
     junitReporter({})