test_runner: report entryFile in TestStream events

Signed-off-by: Moshe Atlov <moshe@atlow.co.il>
PR-URL: #64309
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Chemi Atlow <chemi@atlow.co.il>

Author: MoLow

doc/api/test.md

@@ -3430,6 +3430,10 @@ added:
  - v18.9.0
  - v16.19.0
 changes:
+ - version: REPLACEME
+ pr-url: https://github.com/nodejs/node/pull/64309
+ description: Added `entryFile` to events forwarded from child processes
+ when tests run with process isolation.
  - version: v24.19.0
  pr-url: https://github.com/nodejs/node/pull/63435
  description: Added `parentId` to test events that carry a `testId`.
@@ -3514,6 +3518,10 @@ Emitted when code coverage is enabled and all tests have completed.
 *`cause` {Error} The actual error thrown by the test.
 *`type` {string|undefined} The type of the test, used to denote whether
  this is a suite.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3543,6 +3551,10 @@ The corresponding declaration ordered events are `'test:pass'` and `'test:fail'`
 *`data` {Object}
 *`column` {number|undefined} The column number where the test is defined, or
 `undefined` if the test was run through the REPL.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3569,6 +3581,10 @@ defined. The corresponding declaration ordered event is `'test:start'`.
 *`data` {Object}
 *`column` {number|undefined} The column number where the test is defined, or
 `undefined` if the test was run through the REPL.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3590,6 +3606,10 @@ defined.
 *`data` {Object}
 *`column` {number|undefined} The column number where the test is defined, or
 `undefined` if the test was run through the REPL.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3622,6 +3642,10 @@ Emitted when a test is enqueued for execution.
  this is a suite.
 *`attempt` {number|undefined} The attempt number of the test run,
  present only when using the [`--test-rerun-failures`][] flag.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3685,6 +3709,10 @@ since the parent runner only knows about file-level tests. When using
  present only when using the [`--test-rerun-failures`][] flag.
 *`passed_on_attempt` {number|undefined} The attempt number the test passed on,
  present only when using the [`--test-rerun-failures`][] flag.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3714,6 +3742,10 @@ The corresponding execution ordered event is `'test:complete'`.
 *`data` {Object}
 *`column` {number|undefined} The column number where the test is defined, or
 `undefined` if the test was run through the REPL.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3730,6 +3762,10 @@ defined.
 *`data` {Object}
 *`column` {number|undefined} The column number where the test is defined, or
 `undefined` if the test was run through the REPL.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3754,6 +3790,9 @@ The corresponding execution ordered event is `'test:dequeue'`.
 ### Event: `'test:stderr'`
 
 *`data` {Object}
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation.
 *`file` {string} The path of the test file.
 *`message` {string} The message written to `stderr`.
 
@@ -3765,6 +3804,9 @@ defined.
 ### Event: `'test:stdout'`
 
 *`data` {Object}
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation.
 *`file` {string} The path of the test file.
 *`message` {string} The message written to `stdout`.
 

lib/internal/test_runner/runner.js

@@ -295,6 +295,10 @@ class FileTest extends Test {
 ArrayPrototypeIncludes(kDiagnosticsFilterArgs,StringPrototypeSlice(comment,0,firstSpaceIndex));
 }
  #handleReportItem(item){
+// The name is empty when a single child process runs all test files.
+if(this.name!==''){
+item.data.entryFile=this.loc.file;
+}
 constisTopLevel=item.data.nesting===0;
 if(isTopLevel){
 if(item.type==='test:plan'&&this.#skipReporting()){

test/fixtures/test-runner/entry-file/a.test.mjs

@@ -0,0 +1,3 @@
+import{test}from'node:test';
+import{runShared}from'./helper.mjs';
+test('backup A',async(t)=>{awaitrunShared(t,'A');});

test/fixtures/test-runner/entry-file/b.test.mjs

@@ -0,0 +1,3 @@
+import{test}from'node:test';
+import{runShared}from'./helper.mjs';
+test('backup B',async(t)=>{awaitrunShared(t,'B');});

test/fixtures/test-runner/entry-file/helper.mjs

@@ -0,0 +1,3 @@
+exportasyncfunctionrunShared(t,target){
+awaitt.test(`restore ${target}`,async()=>{});
+}

test/parallel/test-runner-entry-file.mjs

@@ -0,0 +1,59 @@
+import'../common/index.mjs';
+import*asfixturesfrom'../common/fixtures.mjs';
+import{describe,it,run}from'node:test';
+importassertfrom'node:assert';
+
+constaPath=fixtures.path('test-runner','entry-file','a.test.mjs');
+constbPath=fixtures.path('test-runner','entry-file','b.test.mjs');
+consthelperPath=fixtures.path('test-runner','entry-file','helper.mjs');
+
+asyncfunctioncollectEvents(options){
+constevents=[];
+conststream=run({files: [aPath,bPath], ...options});
+stream.on('test:fail',()=>{});
+forawait(consteventofstream){
+events.push(event);
+}
+returnevents;
+}
+
+describe('entryFile attribution in reporter events',{concurrency: false},()=>{
+it('stamps entryFile on events forwarded from child processes',async()=>{
+constevents=awaitcollectEvents({isolation: 'process'});
+constchecked={__proto__: null,A: 0,B: 0};
+
+for(const{ type, data }ofevents){
+if(data?.name==='restore A'||data?.name==='restore B'){
+consttarget=data.name==='restore A' ? 'A' : 'B';
+constexpectedEntry=target==='A' ? aPath : bPath;
+assert.strictEqual(data.file,helperPath,
+`${type} file should be the definition site`);
+assert.strictEqual(data.entryFile,expectedEntry,
+`${type} entryFile should be the entry file`);
+checked[target]++;
+}
+}
+
+// Each subtest emits at least enqueue/dequeue/start/pass/complete.
+assert.ok(checked.A>=4,`expected events for restore A, got ${checked.A}`);
+assert.ok(checked.B>=4,`expected events for restore B, got ${checked.B}`);
+});
+
+it('stamps entryFile on top-level tests forwarded from child processes',async()=>{
+constevents=awaitcollectEvents({isolation: 'process'});
+constpass=events.filter(({ type })=>type==='test:pass');
+constbackupA=pass.find(({ data })=>data.name==='backup A');
+constbackupB=pass.find(({ data })=>data.name==='backup B');
+assert.strictEqual(backupA.data.entryFile,aPath);
+assert.strictEqual(backupB.data.entryFile,bPath);
+});
+
+it('does not stamp entryFile with isolation none',async()=>{
+constevents=awaitcollectEvents({isolation: 'none'});
+for(const{ data }ofevents){
+if(data?.name==='restore A'||data?.name==='restore B'){
+assert.strictEqual(data.entryFile,undefined);
+}
+}
+});
+});

test/parallel/test-runner-v8-deserializer.mjs

@@ -5,6 +5,7 @@ import { describe, it, beforeEach } from 'node:test';
 importassertfrom'node:assert';
 import{finished}from'node:stream/promises';
 import{DefaultSerializer}from'node:v8';
+import{resolve}from'node:path';
 importserializerfrom'internal/test_runner/reporter/v8-serializer';
 importrunnerfrom'internal/test_runner/runner';
 
@@ -14,10 +15,15 @@ async function toArray(chunks) {
 returnarr;
 }
 
+constentryFile=resolve('filetest');
 constdiagnosticEvent={
 type: 'test:diagnostic',
 data: {nesting: 0,details: {},message: 'diagnostic'},
 };
+constreportedDiagnosticEvent={
+type: 'test:diagnostic',
+data: { ...diagnosticEvent.data, entryFile },
+};
 constchunks=awaittoArray(serializer([diagnosticEvent]));
 constdefaultSerializer=newDefaultSerializer();
 defaultSerializer.writeHeader();
@@ -67,28 +73,28 @@ describe('v8 deserializer', common.mustCall(() => {
 it('should deserialize a chunk with no serialization',async()=>{
 constreported=awaitcollectReported([Buffer.from('unknown')]);
 assert.deepStrictEqual(reported,[
-{data: {__proto__: null,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
+{data: {__proto__: null,entryFile,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
 ]);
 });
 
 it('should deserialize a serialized chunk',async()=>{
 constreported=awaitcollectReported(chunks);
-assert.deepStrictEqual(reported,[diagnosticEvent]);
+assert.deepStrictEqual(reported,[reportedDiagnosticEvent]);
 });
 
 it('should deserialize a serialized chunk after non-serialized chunk',async()=>{
 constreported=awaitcollectReported([Buffer.concat([Buffer.from('unknown'), ...chunks])]);
 assert.deepStrictEqual(reported,[
-{data: {__proto__: null,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
-diagnosticEvent,
+{data: {__proto__: null,entryFile,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
+reportedDiagnosticEvent,
 ]);
 });
 
 it('should deserialize a serialized chunk before non-serialized output',async()=>{
 constreported=awaitcollectReported([Buffer.concat([ ...chunks,Buffer.from('unknown')])]);
 assert.deepStrictEqual(reported,[
-diagnosticEvent,
-{data: {__proto__: null,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
+reportedDiagnosticEvent,
+{data: {__proto__: null,entryFile,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
 ]);
 });
 
@@ -131,7 +137,7 @@ describe('v8 deserializer', common.mustCall(() => {
 oversizedLengthHeader,
  ...chunks,
 ]);
-assert.deepStrictEqual(reported.at(-1),diagnosticEvent);
+assert.deepStrictEqual(reported.at(-1),reportedDiagnosticEvent);
 assert.strictEqual(reported.filter((event)=>event.type==='test:diagnostic').length,1);
 assert.strictEqual(collectStdout(reported),oversizedLengthStdout);
 });
@@ -152,7 +158,7 @@ describe('v8 deserializer', common.mustCall(() => {
 constdata=chunks[0];
 constreported=awaitcollectReported([data.subarray(0,i),data.subarray(i)]);
 assert.deepStrictEqual(reported,[
-diagnosticEvent,
+reportedDiagnosticEvent,
 ]);
 });
 
@@ -163,9 +169,9 @@ describe('v8 deserializer', common.mustCall(() => {
 Buffer.concat([data.subarray(i),Buffer.from('unknown')]),
 ]);
 assert.deepStrictEqual(reported,[
-{data: {__proto__: null,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
-diagnosticEvent,
-{data: {__proto__: null,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
+{data: {__proto__: null,entryFile,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
+reportedDiagnosticEvent,
+{data: {__proto__: null,entryFile,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
 ]);
 }
 );

doc/api/test.md

@@ -3430,6 +3430,10 @@ added:
  - v18.9.0
  - v16.19.0
 changes:
+ - version: REPLACEME
+ pr-url: https://github.com/nodejs/node/pull/64309
+ description: Added `entryFile` to events forwarded from child processes
+ when tests run with process isolation.
  - version: v24.19.0
  pr-url: https://github.com/nodejs/node/pull/63435
  description: Added `parentId` to test events that carry a `testId`.
@@ -3514,6 +3518,10 @@ Emitted when code coverage is enabled and all tests have completed.
 *`cause` {Error} The actual error thrown by the test.
 *`type` {string|undefined} The type of the test, used to denote whether
  this is a suite.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3543,6 +3551,10 @@ The corresponding declaration ordered events are `'test:pass'` and `'test:fail'`
 *`data` {Object}
 *`column` {number|undefined} The column number where the test is defined, or
 `undefined` if the test was run through the REPL.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3569,6 +3581,10 @@ defined. The corresponding declaration ordered event is `'test:start'`.
 *`data` {Object}
 *`column` {number|undefined} The column number where the test is defined, or
 `undefined` if the test was run through the REPL.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3590,6 +3606,10 @@ defined.
 *`data` {Object}
 *`column` {number|undefined} The column number where the test is defined, or
 `undefined` if the test was run through the REPL.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3622,6 +3642,10 @@ Emitted when a test is enqueued for execution.
  this is a suite.
 *`attempt` {number|undefined} The attempt number of the test run,
  present only when using the [`--test-rerun-failures`][] flag.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3685,6 +3709,10 @@ since the parent runner only knows about file-level tests. When using
  present only when using the [`--test-rerun-failures`][] flag.
 *`passed_on_attempt` {number|undefined} The attempt number the test passed on,
  present only when using the [`--test-rerun-failures`][] flag.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3714,6 +3742,10 @@ The corresponding execution ordered event is `'test:complete'`.
 *`data` {Object}
 *`column` {number|undefined} The column number where the test is defined, or
 `undefined` if the test was run through the REPL.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3730,6 +3762,10 @@ defined.
 *`data` {Object}
 *`column` {number|undefined} The column number where the test is defined, or
 `undefined` if the test was run through the REPL.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3754,6 +3790,9 @@ The corresponding execution ordered event is `'test:dequeue'`.
 ### Event: `'test:stderr'`
 
 *`data` {Object}
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation.
 *`file` {string} The path of the test file.
 *`message` {string} The message written to `stderr`.
 
@@ -3765,6 +3804,9 @@ defined.
 ### Event: `'test:stdout'`
 
 *`data` {Object}
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation.
 *`file` {string} The path of the test file.
 *`message` {string} The message written to `stdout`.
 

lib/internal/test_runner/runner.js

@@ -295,6 +295,10 @@ class FileTest extends Test {
 ArrayPrototypeIncludes(kDiagnosticsFilterArgs,StringPrototypeSlice(comment,0,firstSpaceIndex));
 }
  #handleReportItem(item){
+// The name is empty when a single child process runs all test files.
+if(this.name!==''){
+item.data.entryFile=this.loc.file;
+}
 constisTopLevel=item.data.nesting===0;
 if(isTopLevel){
 if(item.type==='test:plan'&&this.#skipReporting()){

test/fixtures/test-runner/entry-file/a.test.mjs

@@ -0,0 +1,3 @@
+import{test}from'node:test';
+import{runShared}from'./helper.mjs';
+test('backup A',async(t)=>{awaitrunShared(t,'A');});

test/fixtures/test-runner/entry-file/b.test.mjs

@@ -0,0 +1,3 @@
+import{test}from'node:test';
+import{runShared}from'./helper.mjs';
+test('backup B',async(t)=>{awaitrunShared(t,'B');});

test/fixtures/test-runner/entry-file/helper.mjs

@@ -0,0 +1,3 @@
+exportasyncfunctionrunShared(t,target){
+awaitt.test(`restore ${target}`,async()=>{});
+}

test/parallel/test-runner-entry-file.mjs

@@ -0,0 +1,59 @@
+import'../common/index.mjs';
+import*asfixturesfrom'../common/fixtures.mjs';
+import{describe,it,run}from'node:test';
+importassertfrom'node:assert';
+
+constaPath=fixtures.path('test-runner','entry-file','a.test.mjs');
+constbPath=fixtures.path('test-runner','entry-file','b.test.mjs');
+consthelperPath=fixtures.path('test-runner','entry-file','helper.mjs');
+
+asyncfunctioncollectEvents(options){
+constevents=[];
+conststream=run({files: [aPath,bPath], ...options});
+stream.on('test:fail',()=>{});
+forawait(consteventofstream){
+events.push(event);
+}
+returnevents;
+}
+
+describe('entryFile attribution in reporter events',{concurrency: false},()=>{
+it('stamps entryFile on events forwarded from child processes',async()=>{
+constevents=awaitcollectEvents({isolation: 'process'});
+constchecked={__proto__: null,A: 0,B: 0};
+
+for(const{ type, data }ofevents){
+if(data?.name==='restore A'||data?.name==='restore B'){
+consttarget=data.name==='restore A' ? 'A' : 'B';
+constexpectedEntry=target==='A' ? aPath : bPath;
+assert.strictEqual(data.file,helperPath,
+`${type} file should be the definition site`);
+assert.strictEqual(data.entryFile,expectedEntry,
+`${type} entryFile should be the entry file`);
+checked[target]++;
+}
+}
+
+// Each subtest emits at least enqueue/dequeue/start/pass/complete.
+assert.ok(checked.A>=4,`expected events for restore A, got ${checked.A}`);
+assert.ok(checked.B>=4,`expected events for restore B, got ${checked.B}`);
+});
+
+it('stamps entryFile on top-level tests forwarded from child processes',async()=>{
+constevents=awaitcollectEvents({isolation: 'process'});
+constpass=events.filter(({ type })=>type==='test:pass');
+constbackupA=pass.find(({ data })=>data.name==='backup A');
+constbackupB=pass.find(({ data })=>data.name==='backup B');
+assert.strictEqual(backupA.data.entryFile,aPath);
+assert.strictEqual(backupB.data.entryFile,bPath);
+});
+
+it('does not stamp entryFile with isolation none',async()=>{
+constevents=awaitcollectEvents({isolation: 'none'});
+for(const{ data }ofevents){
+if(data?.name==='restore A'||data?.name==='restore B'){
+assert.strictEqual(data.entryFile,undefined);
+}
+}
+});
+});

test/parallel/test-runner-v8-deserializer.mjs

@@ -5,6 +5,7 @@ import { describe, it, beforeEach } from 'node:test';
 importassertfrom'node:assert';
 import{finished}from'node:stream/promises';
 import{DefaultSerializer}from'node:v8';
+import{resolve}from'node:path';
 importserializerfrom'internal/test_runner/reporter/v8-serializer';
 importrunnerfrom'internal/test_runner/runner';
 
@@ -14,10 +15,15 @@ async function toArray(chunks) {
 returnarr;
 }
 
+constentryFile=resolve('filetest');
 constdiagnosticEvent={
 type: 'test:diagnostic',
 data: {nesting: 0,details: {},message: 'diagnostic'},
 };
+constreportedDiagnosticEvent={
+type: 'test:diagnostic',
+data: { ...diagnosticEvent.data, entryFile },
+};
 constchunks=awaittoArray(serializer([diagnosticEvent]));
 constdefaultSerializer=newDefaultSerializer();
 defaultSerializer.writeHeader();
@@ -67,28 +73,28 @@ describe('v8 deserializer', common.mustCall(() => {
 it('should deserialize a chunk with no serialization',async()=>{
 constreported=awaitcollectReported([Buffer.from('unknown')]);
 assert.deepStrictEqual(reported,[
-{data: {__proto__: null,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
+{data: {__proto__: null,entryFile,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
 ]);
 });
 
 it('should deserialize a serialized chunk',async()=>{
 constreported=awaitcollectReported(chunks);
-assert.deepStrictEqual(reported,[diagnosticEvent]);
+assert.deepStrictEqual(reported,[reportedDiagnosticEvent]);
 });
 
 it('should deserialize a serialized chunk after non-serialized chunk',async()=>{
 constreported=awaitcollectReported([Buffer.concat([Buffer.from('unknown'), ...chunks])]);
 assert.deepStrictEqual(reported,[
-{data: {__proto__: null,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
-diagnosticEvent,
+{data: {__proto__: null,entryFile,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
+reportedDiagnosticEvent,
 ]);
 });
 
 it('should deserialize a serialized chunk before non-serialized output',async()=>{
 constreported=awaitcollectReported([Buffer.concat([ ...chunks,Buffer.from('unknown')])]);
 assert.deepStrictEqual(reported,[
-diagnosticEvent,
-{data: {__proto__: null,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
+reportedDiagnosticEvent,
+{data: {__proto__: null,entryFile,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
 ]);
 });
 
@@ -131,7 +137,7 @@ describe('v8 deserializer', common.mustCall(() => {
 oversizedLengthHeader,
  ...chunks,
 ]);
-assert.deepStrictEqual(reported.at(-1),diagnosticEvent);
+assert.deepStrictEqual(reported.at(-1),reportedDiagnosticEvent);
 assert.strictEqual(reported.filter((event)=>event.type==='test:diagnostic').length,1);
 assert.strictEqual(collectStdout(reported),oversizedLengthStdout);
 });
@@ -152,7 +158,7 @@ describe('v8 deserializer', common.mustCall(() => {
 constdata=chunks[0];
 constreported=awaitcollectReported([data.subarray(0,i),data.subarray(i)]);
 assert.deepStrictEqual(reported,[
-diagnosticEvent,
+reportedDiagnosticEvent,
 ]);
 });
 
@@ -163,9 +169,9 @@ describe('v8 deserializer', common.mustCall(() => {
 Buffer.concat([data.subarray(i),Buffer.from('unknown')]),
 ]);
 assert.deepStrictEqual(reported,[
-{data: {__proto__: null,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
-diagnosticEvent,
-{data: {__proto__: null,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
+{data: {__proto__: null,entryFile,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
+reportedDiagnosticEvent,
+{data: {__proto__: null,entryFile,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
 ]);
 }
 );

doc/api/test.md

@@ -3430,6 +3430,10 @@ added:
  - v18.9.0
  - v16.19.0
 changes:
+ - version: REPLACEME
+ pr-url: https://github.com/nodejs/node/pull/64309
+ description: Added `entryFile` to events forwarded from child processes
+ when tests run with process isolation.
  - version: v24.19.0
  pr-url: https://github.com/nodejs/node/pull/63435
  description: Added `parentId` to test events that carry a `testId`.
@@ -3514,6 +3518,10 @@ Emitted when code coverage is enabled and all tests have completed.
 *`cause` {Error} The actual error thrown by the test.
 *`type` {string|undefined} The type of the test, used to denote whether
  this is a suite.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3543,6 +3551,10 @@ The corresponding declaration ordered events are `'test:pass'` and `'test:fail'`
 *`data` {Object}
 *`column` {number|undefined} The column number where the test is defined, or
 `undefined` if the test was run through the REPL.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3569,6 +3581,10 @@ defined. The corresponding declaration ordered event is `'test:start'`.
 *`data` {Object}
 *`column` {number|undefined} The column number where the test is defined, or
 `undefined` if the test was run through the REPL.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3590,6 +3606,10 @@ defined.
 *`data` {Object}
 *`column` {number|undefined} The column number where the test is defined, or
 `undefined` if the test was run through the REPL.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3622,6 +3642,10 @@ Emitted when a test is enqueued for execution.
  this is a suite.
 *`attempt` {number|undefined} The attempt number of the test run,
  present only when using the [`--test-rerun-failures`][] flag.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3685,6 +3709,10 @@ since the parent runner only knows about file-level tests. When using
  present only when using the [`--test-rerun-failures`][] flag.
 *`passed_on_attempt` {number|undefined} The attempt number the test passed on,
  present only when using the [`--test-rerun-failures`][] flag.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3714,6 +3742,10 @@ The corresponding execution ordered event is `'test:complete'`.
 *`data` {Object}
 *`column` {number|undefined} The column number where the test is defined, or
 `undefined` if the test was run through the REPL.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3730,6 +3762,10 @@ defined.
 *`data` {Object}
 *`column` {number|undefined} The column number where the test is defined, or
 `undefined` if the test was run through the REPL.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3754,6 +3790,9 @@ The corresponding execution ordered event is `'test:dequeue'`.
 ### Event: `'test:stderr'`
 
 *`data` {Object}
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation.
 *`file` {string} The path of the test file.
 *`message` {string} The message written to `stderr`.
 
@@ -3765,6 +3804,9 @@ defined.
 ### Event: `'test:stdout'`
 
 *`data` {Object}
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation.
 *`file` {string} The path of the test file.
 *`message` {string} The message written to `stdout`.
 

lib/internal/test_runner/runner.js

@@ -295,6 +295,10 @@ class FileTest extends Test {
 ArrayPrototypeIncludes(kDiagnosticsFilterArgs,StringPrototypeSlice(comment,0,firstSpaceIndex));
 }
  #handleReportItem(item){
+// The name is empty when a single child process runs all test files.
+if(this.name!==''){
+item.data.entryFile=this.loc.file;
+}
 constisTopLevel=item.data.nesting===0;
 if(isTopLevel){
 if(item.type==='test:plan'&&this.#skipReporting()){

test/fixtures/test-runner/entry-file/a.test.mjs

@@ -0,0 +1,3 @@
+import{test}from'node:test';
+import{runShared}from'./helper.mjs';
+test('backup A',async(t)=>{awaitrunShared(t,'A');});

test/fixtures/test-runner/entry-file/b.test.mjs

@@ -0,0 +1,3 @@
+import{test}from'node:test';
+import{runShared}from'./helper.mjs';
+test('backup B',async(t)=>{awaitrunShared(t,'B');});

test/fixtures/test-runner/entry-file/helper.mjs

@@ -0,0 +1,3 @@
+exportasyncfunctionrunShared(t,target){
+awaitt.test(`restore ${target}`,async()=>{});
+}

test/parallel/test-runner-entry-file.mjs

@@ -0,0 +1,59 @@
+import'../common/index.mjs';
+import*asfixturesfrom'../common/fixtures.mjs';
+import{describe,it,run}from'node:test';
+importassertfrom'node:assert';
+
+constaPath=fixtures.path('test-runner','entry-file','a.test.mjs');
+constbPath=fixtures.path('test-runner','entry-file','b.test.mjs');
+consthelperPath=fixtures.path('test-runner','entry-file','helper.mjs');
+
+asyncfunctioncollectEvents(options){
+constevents=[];
+conststream=run({files: [aPath,bPath], ...options});
+stream.on('test:fail',()=>{});
+forawait(consteventofstream){
+events.push(event);
+}
+returnevents;
+}
+
+describe('entryFile attribution in reporter events',{concurrency: false},()=>{
+it('stamps entryFile on events forwarded from child processes',async()=>{
+constevents=awaitcollectEvents({isolation: 'process'});
+constchecked={__proto__: null,A: 0,B: 0};
+
+for(const{ type, data }ofevents){
+if(data?.name==='restore A'||data?.name==='restore B'){
+consttarget=data.name==='restore A' ? 'A' : 'B';
+constexpectedEntry=target==='A' ? aPath : bPath;
+assert.strictEqual(data.file,helperPath,
+`${type} file should be the definition site`);
+assert.strictEqual(data.entryFile,expectedEntry,
+`${type} entryFile should be the entry file`);
+checked[target]++;
+}
+}
+
+// Each subtest emits at least enqueue/dequeue/start/pass/complete.
+assert.ok(checked.A>=4,`expected events for restore A, got ${checked.A}`);
+assert.ok(checked.B>=4,`expected events for restore B, got ${checked.B}`);
+});
+
+it('stamps entryFile on top-level tests forwarded from child processes',async()=>{
+constevents=awaitcollectEvents({isolation: 'process'});
+constpass=events.filter(({ type })=>type==='test:pass');
+constbackupA=pass.find(({ data })=>data.name==='backup A');
+constbackupB=pass.find(({ data })=>data.name==='backup B');
+assert.strictEqual(backupA.data.entryFile,aPath);
+assert.strictEqual(backupB.data.entryFile,bPath);
+});
+
+it('does not stamp entryFile with isolation none',async()=>{
+constevents=awaitcollectEvents({isolation: 'none'});
+for(const{ data }ofevents){
+if(data?.name==='restore A'||data?.name==='restore B'){
+assert.strictEqual(data.entryFile,undefined);
+}
+}
+});
+});

test/parallel/test-runner-v8-deserializer.mjs

@@ -5,6 +5,7 @@ import { describe, it, beforeEach } from 'node:test';
 importassertfrom'node:assert';
 import{finished}from'node:stream/promises';
 import{DefaultSerializer}from'node:v8';
+import{resolve}from'node:path';
 importserializerfrom'internal/test_runner/reporter/v8-serializer';
 importrunnerfrom'internal/test_runner/runner';
 
@@ -14,10 +15,15 @@ async function toArray(chunks) {
 returnarr;
 }
 
+constentryFile=resolve('filetest');
 constdiagnosticEvent={
 type: 'test:diagnostic',
 data: {nesting: 0,details: {},message: 'diagnostic'},
 };
+constreportedDiagnosticEvent={
+type: 'test:diagnostic',
+data: { ...diagnosticEvent.data, entryFile },
+};
 constchunks=awaittoArray(serializer([diagnosticEvent]));
 constdefaultSerializer=newDefaultSerializer();
 defaultSerializer.writeHeader();
@@ -67,28 +73,28 @@ describe('v8 deserializer', common.mustCall(() => {
 it('should deserialize a chunk with no serialization',async()=>{
 constreported=awaitcollectReported([Buffer.from('unknown')]);
 assert.deepStrictEqual(reported,[
-{data: {__proto__: null,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
+{data: {__proto__: null,entryFile,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
 ]);
 });
 
 it('should deserialize a serialized chunk',async()=>{
 constreported=awaitcollectReported(chunks);
-assert.deepStrictEqual(reported,[diagnosticEvent]);
+assert.deepStrictEqual(reported,[reportedDiagnosticEvent]);
 });
 
 it('should deserialize a serialized chunk after non-serialized chunk',async()=>{
 constreported=awaitcollectReported([Buffer.concat([Buffer.from('unknown'), ...chunks])]);
 assert.deepStrictEqual(reported,[
-{data: {__proto__: null,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
-diagnosticEvent,
+{data: {__proto__: null,entryFile,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
+reportedDiagnosticEvent,
 ]);
 });
 
 it('should deserialize a serialized chunk before non-serialized output',async()=>{
 constreported=awaitcollectReported([Buffer.concat([ ...chunks,Buffer.from('unknown')])]);
 assert.deepStrictEqual(reported,[
-diagnosticEvent,
-{data: {__proto__: null,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
+reportedDiagnosticEvent,
+{data: {__proto__: null,entryFile,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
 ]);
 });
 
@@ -131,7 +137,7 @@ describe('v8 deserializer', common.mustCall(() => {
 oversizedLengthHeader,
  ...chunks,
 ]);
-assert.deepStrictEqual(reported.at(-1),diagnosticEvent);
+assert.deepStrictEqual(reported.at(-1),reportedDiagnosticEvent);
 assert.strictEqual(reported.filter((event)=>event.type==='test:diagnostic').length,1);
 assert.strictEqual(collectStdout(reported),oversizedLengthStdout);
 });
@@ -152,7 +158,7 @@ describe('v8 deserializer', common.mustCall(() => {
 constdata=chunks[0];
 constreported=awaitcollectReported([data.subarray(0,i),data.subarray(i)]);
 assert.deepStrictEqual(reported,[
-diagnosticEvent,
+reportedDiagnosticEvent,
 ]);
 });
 
@@ -163,9 +169,9 @@ describe('v8 deserializer', common.mustCall(() => {
 Buffer.concat([data.subarray(i),Buffer.from('unknown')]),
 ]);
 assert.deepStrictEqual(reported,[
-{data: {__proto__: null,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
-diagnosticEvent,
-{data: {__proto__: null,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
+{data: {__proto__: null,entryFile,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
+reportedDiagnosticEvent,
+{data: {__proto__: null,entryFile,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
 ]);
 }
 );

doc/api/test.md

@@ -3430,6 +3430,10 @@ added:
  - v18.9.0
  - v16.19.0
 changes:
+ - version: REPLACEME
+ pr-url: https://github.com/nodejs/node/pull/64309
+ description: Added `entryFile` to events forwarded from child processes
+ when tests run with process isolation.
  - version: v24.19.0
  pr-url: https://github.com/nodejs/node/pull/63435
  description: Added `parentId` to test events that carry a `testId`.
@@ -3514,6 +3518,10 @@ Emitted when code coverage is enabled and all tests have completed.
 *`cause` {Error} The actual error thrown by the test.
 *`type` {string|undefined} The type of the test, used to denote whether
  this is a suite.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3543,6 +3551,10 @@ The corresponding declaration ordered events are `'test:pass'` and `'test:fail'`
 *`data` {Object}
 *`column` {number|undefined} The column number where the test is defined, or
 `undefined` if the test was run through the REPL.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3569,6 +3581,10 @@ defined. The corresponding declaration ordered event is `'test:start'`.
 *`data` {Object}
 *`column` {number|undefined} The column number where the test is defined, or
 `undefined` if the test was run through the REPL.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3590,6 +3606,10 @@ defined.
 *`data` {Object}
 *`column` {number|undefined} The column number where the test is defined, or
 `undefined` if the test was run through the REPL.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3622,6 +3642,10 @@ Emitted when a test is enqueued for execution.
  this is a suite.
 *`attempt` {number|undefined} The attempt number of the test run,
  present only when using the [`--test-rerun-failures`][] flag.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3685,6 +3709,10 @@ since the parent runner only knows about file-level tests. When using
  present only when using the [`--test-rerun-failures`][] flag.
 *`passed_on_attempt` {number|undefined} The attempt number the test passed on,
  present only when using the [`--test-rerun-failures`][] flag.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3714,6 +3742,10 @@ The corresponding execution ordered event is `'test:complete'`.
 *`data` {Object}
 *`column` {number|undefined} The column number where the test is defined, or
 `undefined` if the test was run through the REPL.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3730,6 +3762,10 @@ defined.
 *`data` {Object}
 *`column` {number|undefined} The column number where the test is defined, or
 `undefined` if the test was run through the REPL.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3754,6 +3790,9 @@ The corresponding execution ordered event is `'test:dequeue'`.
 ### Event: `'test:stderr'`
 
 *`data` {Object}
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation.
 *`file` {string} The path of the test file.
 *`message` {string} The message written to `stderr`.
 
@@ -3765,6 +3804,9 @@ defined.
 ### Event: `'test:stdout'`
 
 *`data` {Object}
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation.
 *`file` {string} The path of the test file.
 *`message` {string} The message written to `stdout`.
 

lib/internal/test_runner/runner.js

@@ -295,6 +295,10 @@ class FileTest extends Test {
 ArrayPrototypeIncludes(kDiagnosticsFilterArgs,StringPrototypeSlice(comment,0,firstSpaceIndex));
 }
  #handleReportItem(item){
+// The name is empty when a single child process runs all test files.
+if(this.name!==''){
+item.data.entryFile=this.loc.file;
+}
 constisTopLevel=item.data.nesting===0;
 if(isTopLevel){
 if(item.type==='test:plan'&&this.#skipReporting()){

test/fixtures/test-runner/entry-file/a.test.mjs

@@ -0,0 +1,3 @@
+import{test}from'node:test';
+import{runShared}from'./helper.mjs';
+test('backup A',async(t)=>{awaitrunShared(t,'A');});

test/fixtures/test-runner/entry-file/b.test.mjs

@@ -0,0 +1,3 @@
+import{test}from'node:test';
+import{runShared}from'./helper.mjs';
+test('backup B',async(t)=>{awaitrunShared(t,'B');});

test/fixtures/test-runner/entry-file/helper.mjs

@@ -0,0 +1,3 @@
+exportasyncfunctionrunShared(t,target){
+awaitt.test(`restore ${target}`,async()=>{});
+}

test/parallel/test-runner-entry-file.mjs

@@ -0,0 +1,59 @@
+import'../common/index.mjs';
+import*asfixturesfrom'../common/fixtures.mjs';
+import{describe,it,run}from'node:test';
+importassertfrom'node:assert';
+
+constaPath=fixtures.path('test-runner','entry-file','a.test.mjs');
+constbPath=fixtures.path('test-runner','entry-file','b.test.mjs');
+consthelperPath=fixtures.path('test-runner','entry-file','helper.mjs');
+
+asyncfunctioncollectEvents(options){
+constevents=[];
+conststream=run({files: [aPath,bPath], ...options});
+stream.on('test:fail',()=>{});
+forawait(consteventofstream){
+events.push(event);
+}
+returnevents;
+}
+
+describe('entryFile attribution in reporter events',{concurrency: false},()=>{
+it('stamps entryFile on events forwarded from child processes',async()=>{
+constevents=awaitcollectEvents({isolation: 'process'});
+constchecked={__proto__: null,A: 0,B: 0};
+
+for(const{ type, data }ofevents){
+if(data?.name==='restore A'||data?.name==='restore B'){
+consttarget=data.name==='restore A' ? 'A' : 'B';
+constexpectedEntry=target==='A' ? aPath : bPath;
+assert.strictEqual(data.file,helperPath,
+`${type} file should be the definition site`);
+assert.strictEqual(data.entryFile,expectedEntry,
+`${type} entryFile should be the entry file`);
+checked[target]++;
+}
+}
+
+// Each subtest emits at least enqueue/dequeue/start/pass/complete.
+assert.ok(checked.A>=4,`expected events for restore A, got ${checked.A}`);
+assert.ok(checked.B>=4,`expected events for restore B, got ${checked.B}`);
+});
+
+it('stamps entryFile on top-level tests forwarded from child processes',async()=>{
+constevents=awaitcollectEvents({isolation: 'process'});
+constpass=events.filter(({ type })=>type==='test:pass');
+constbackupA=pass.find(({ data })=>data.name==='backup A');
+constbackupB=pass.find(({ data })=>data.name==='backup B');
+assert.strictEqual(backupA.data.entryFile,aPath);
+assert.strictEqual(backupB.data.entryFile,bPath);
+});
+
+it('does not stamp entryFile with isolation none',async()=>{
+constevents=awaitcollectEvents({isolation: 'none'});
+for(const{ data }ofevents){
+if(data?.name==='restore A'||data?.name==='restore B'){
+assert.strictEqual(data.entryFile,undefined);
+}
+}
+});
+});

test/parallel/test-runner-v8-deserializer.mjs

@@ -5,6 +5,7 @@ import { describe, it, beforeEach } from 'node:test';
 importassertfrom'node:assert';
 import{finished}from'node:stream/promises';
 import{DefaultSerializer}from'node:v8';
+import{resolve}from'node:path';
 importserializerfrom'internal/test_runner/reporter/v8-serializer';
 importrunnerfrom'internal/test_runner/runner';
 
@@ -14,10 +15,15 @@ async function toArray(chunks) {
 returnarr;
 }
 
+constentryFile=resolve('filetest');
 constdiagnosticEvent={
 type: 'test:diagnostic',
 data: {nesting: 0,details: {},message: 'diagnostic'},
 };
+constreportedDiagnosticEvent={
+type: 'test:diagnostic',
+data: { ...diagnosticEvent.data, entryFile },
+};
 constchunks=awaittoArray(serializer([diagnosticEvent]));
 constdefaultSerializer=newDefaultSerializer();
 defaultSerializer.writeHeader();
@@ -67,28 +73,28 @@ describe('v8 deserializer', common.mustCall(() => {
 it('should deserialize a chunk with no serialization',async()=>{
 constreported=awaitcollectReported([Buffer.from('unknown')]);
 assert.deepStrictEqual(reported,[
-{data: {__proto__: null,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
+{data: {__proto__: null,entryFile,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
 ]);
 });
 
 it('should deserialize a serialized chunk',async()=>{
 constreported=awaitcollectReported(chunks);
-assert.deepStrictEqual(reported,[diagnosticEvent]);
+assert.deepStrictEqual(reported,[reportedDiagnosticEvent]);
 });
 
 it('should deserialize a serialized chunk after non-serialized chunk',async()=>{
 constreported=awaitcollectReported([Buffer.concat([Buffer.from('unknown'), ...chunks])]);
 assert.deepStrictEqual(reported,[
-{data: {__proto__: null,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
-diagnosticEvent,
+{data: {__proto__: null,entryFile,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
+reportedDiagnosticEvent,
 ]);
 });
 
 it('should deserialize a serialized chunk before non-serialized output',async()=>{
 constreported=awaitcollectReported([Buffer.concat([ ...chunks,Buffer.from('unknown')])]);
 assert.deepStrictEqual(reported,[
-diagnosticEvent,
-{data: {__proto__: null,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
+reportedDiagnosticEvent,
+{data: {__proto__: null,entryFile,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
 ]);
 });
 
@@ -131,7 +137,7 @@ describe('v8 deserializer', common.mustCall(() => {
 oversizedLengthHeader,
  ...chunks,
 ]);
-assert.deepStrictEqual(reported.at(-1),diagnosticEvent);
+assert.deepStrictEqual(reported.at(-1),reportedDiagnosticEvent);
 assert.strictEqual(reported.filter((event)=>event.type==='test:diagnostic').length,1);
 assert.strictEqual(collectStdout(reported),oversizedLengthStdout);
 });
@@ -152,7 +158,7 @@ describe('v8 deserializer', common.mustCall(() => {
 constdata=chunks[0];
 constreported=awaitcollectReported([data.subarray(0,i),data.subarray(i)]);
 assert.deepStrictEqual(reported,[
-diagnosticEvent,
+reportedDiagnosticEvent,
 ]);
 });
 
@@ -163,9 +169,9 @@ describe('v8 deserializer', common.mustCall(() => {
 Buffer.concat([data.subarray(i),Buffer.from('unknown')]),
 ]);
 assert.deepStrictEqual(reported,[
-{data: {__proto__: null,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
-diagnosticEvent,
-{data: {__proto__: null,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
+{data: {__proto__: null,entryFile,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
+reportedDiagnosticEvent,
+{data: {__proto__: null,entryFile,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
 ]);
 }
 );

doc/api/test.md

@@ -3430,6 +3430,10 @@ added:
  - v18.9.0
  - v16.19.0
 changes:
+ - version: REPLACEME
+ pr-url: https://github.com/nodejs/node/pull/64309
+ description: Added `entryFile` to events forwarded from child processes
+ when tests run with process isolation.
  - version: v24.19.0
  pr-url: https://github.com/nodejs/node/pull/63435
  description: Added `parentId` to test events that carry a `testId`.
@@ -3514,6 +3518,10 @@ Emitted when code coverage is enabled and all tests have completed.
 *`cause` {Error} The actual error thrown by the test.
 *`type` {string|undefined} The type of the test, used to denote whether
  this is a suite.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3543,6 +3551,10 @@ The corresponding declaration ordered events are `'test:pass'` and `'test:fail'`
 *`data` {Object}
 *`column` {number|undefined} The column number where the test is defined, or
 `undefined` if the test was run through the REPL.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3569,6 +3581,10 @@ defined. The corresponding declaration ordered event is `'test:start'`.
 *`data` {Object}
 *`column` {number|undefined} The column number where the test is defined, or
 `undefined` if the test was run through the REPL.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3590,6 +3606,10 @@ defined.
 *`data` {Object}
 *`column` {number|undefined} The column number where the test is defined, or
 `undefined` if the test was run through the REPL.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3622,6 +3642,10 @@ Emitted when a test is enqueued for execution.
  this is a suite.
 *`attempt` {number|undefined} The attempt number of the test run,
  present only when using the [`--test-rerun-failures`][] flag.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3685,6 +3709,10 @@ since the parent runner only knows about file-level tests. When using
  present only when using the [`--test-rerun-failures`][] flag.
 *`passed_on_attempt` {number|undefined} The attempt number the test passed on,
  present only when using the [`--test-rerun-failures`][] flag.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3714,6 +3742,10 @@ The corresponding execution ordered event is `'test:complete'`.
 *`data` {Object}
 *`column` {number|undefined} The column number where the test is defined, or
 `undefined` if the test was run through the REPL.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3730,6 +3762,10 @@ defined.
 *`data` {Object}
 *`column` {number|undefined} The column number where the test is defined, or
 `undefined` if the test was run through the REPL.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3754,6 +3790,9 @@ The corresponding execution ordered event is `'test:dequeue'`.
 ### Event: `'test:stderr'`
 
 *`data` {Object}
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation.
 *`file` {string} The path of the test file.
 *`message` {string} The message written to `stderr`.
 
@@ -3765,6 +3804,9 @@ defined.
 ### Event: `'test:stdout'`
 
 *`data` {Object}
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation.
 *`file` {string} The path of the test file.
 *`message` {string} The message written to `stdout`.
 

lib/internal/test_runner/runner.js

@@ -295,6 +295,10 @@ class FileTest extends Test {
 ArrayPrototypeIncludes(kDiagnosticsFilterArgs,StringPrototypeSlice(comment,0,firstSpaceIndex));
 }
  #handleReportItem(item){
+// The name is empty when a single child process runs all test files.
+if(this.name!==''){
+item.data.entryFile=this.loc.file;
+}
 constisTopLevel=item.data.nesting===0;
 if(isTopLevel){
 if(item.type==='test:plan'&&this.#skipReporting()){

test/fixtures/test-runner/entry-file/a.test.mjs

@@ -0,0 +1,3 @@
+import{test}from'node:test';
+import{runShared}from'./helper.mjs';
+test('backup A',async(t)=>{awaitrunShared(t,'A');});

test/fixtures/test-runner/entry-file/b.test.mjs

@@ -0,0 +1,3 @@
+import{test}from'node:test';
+import{runShared}from'./helper.mjs';
+test('backup B',async(t)=>{awaitrunShared(t,'B');});

test/fixtures/test-runner/entry-file/helper.mjs

@@ -0,0 +1,3 @@
+exportasyncfunctionrunShared(t,target){
+awaitt.test(`restore ${target}`,async()=>{});
+}

test/parallel/test-runner-entry-file.mjs

@@ -0,0 +1,59 @@
+import'../common/index.mjs';
+import*asfixturesfrom'../common/fixtures.mjs';
+import{describe,it,run}from'node:test';
+importassertfrom'node:assert';
+
+constaPath=fixtures.path('test-runner','entry-file','a.test.mjs');
+constbPath=fixtures.path('test-runner','entry-file','b.test.mjs');
+consthelperPath=fixtures.path('test-runner','entry-file','helper.mjs');
+
+asyncfunctioncollectEvents(options){
+constevents=[];
+conststream=run({files: [aPath,bPath], ...options});
+stream.on('test:fail',()=>{});
+forawait(consteventofstream){
+events.push(event);
+}
+returnevents;
+}
+
+describe('entryFile attribution in reporter events',{concurrency: false},()=>{
+it('stamps entryFile on events forwarded from child processes',async()=>{
+constevents=awaitcollectEvents({isolation: 'process'});
+constchecked={__proto__: null,A: 0,B: 0};
+
+for(const{ type, data }ofevents){
+if(data?.name==='restore A'||data?.name==='restore B'){
+consttarget=data.name==='restore A' ? 'A' : 'B';
+constexpectedEntry=target==='A' ? aPath : bPath;
+assert.strictEqual(data.file,helperPath,
+`${type} file should be the definition site`);
+assert.strictEqual(data.entryFile,expectedEntry,
+`${type} entryFile should be the entry file`);
+checked[target]++;
+}
+}
+
+// Each subtest emits at least enqueue/dequeue/start/pass/complete.
+assert.ok(checked.A>=4,`expected events for restore A, got ${checked.A}`);
+assert.ok(checked.B>=4,`expected events for restore B, got ${checked.B}`);
+});
+
+it('stamps entryFile on top-level tests forwarded from child processes',async()=>{
+constevents=awaitcollectEvents({isolation: 'process'});
+constpass=events.filter(({ type })=>type==='test:pass');
+constbackupA=pass.find(({ data })=>data.name==='backup A');
+constbackupB=pass.find(({ data })=>data.name==='backup B');
+assert.strictEqual(backupA.data.entryFile,aPath);
+assert.strictEqual(backupB.data.entryFile,bPath);
+});
+
+it('does not stamp entryFile with isolation none',async()=>{
+constevents=awaitcollectEvents({isolation: 'none'});
+for(const{ data }ofevents){
+if(data?.name==='restore A'||data?.name==='restore B'){
+assert.strictEqual(data.entryFile,undefined);
+}
+}
+});
+});

test/parallel/test-runner-v8-deserializer.mjs

@@ -5,6 +5,7 @@ import { describe, it, beforeEach } from 'node:test';
 importassertfrom'node:assert';
 import{finished}from'node:stream/promises';
 import{DefaultSerializer}from'node:v8';
+import{resolve}from'node:path';
 importserializerfrom'internal/test_runner/reporter/v8-serializer';
 importrunnerfrom'internal/test_runner/runner';
 
@@ -14,10 +15,15 @@ async function toArray(chunks) {
 returnarr;
 }
 
+constentryFile=resolve('filetest');
 constdiagnosticEvent={
 type: 'test:diagnostic',
 data: {nesting: 0,details: {},message: 'diagnostic'},
 };
+constreportedDiagnosticEvent={
+type: 'test:diagnostic',
+data: { ...diagnosticEvent.data, entryFile },
+};
 constchunks=awaittoArray(serializer([diagnosticEvent]));
 constdefaultSerializer=newDefaultSerializer();
 defaultSerializer.writeHeader();
@@ -67,28 +73,28 @@ describe('v8 deserializer', common.mustCall(() => {
 it('should deserialize a chunk with no serialization',async()=>{
 constreported=awaitcollectReported([Buffer.from('unknown')]);
 assert.deepStrictEqual(reported,[
-{data: {__proto__: null,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
+{data: {__proto__: null,entryFile,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
 ]);
 });
 
 it('should deserialize a serialized chunk',async()=>{
 constreported=awaitcollectReported(chunks);
-assert.deepStrictEqual(reported,[diagnosticEvent]);
+assert.deepStrictEqual(reported,[reportedDiagnosticEvent]);
 });
 
 it('should deserialize a serialized chunk after non-serialized chunk',async()=>{
 constreported=awaitcollectReported([Buffer.concat([Buffer.from('unknown'), ...chunks])]);
 assert.deepStrictEqual(reported,[
-{data: {__proto__: null,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
-diagnosticEvent,
+{data: {__proto__: null,entryFile,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
+reportedDiagnosticEvent,
 ]);
 });
 
 it('should deserialize a serialized chunk before non-serialized output',async()=>{
 constreported=awaitcollectReported([Buffer.concat([ ...chunks,Buffer.from('unknown')])]);
 assert.deepStrictEqual(reported,[
-diagnosticEvent,
-{data: {__proto__: null,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
+reportedDiagnosticEvent,
+{data: {__proto__: null,entryFile,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
 ]);
 });
 
@@ -131,7 +137,7 @@ describe('v8 deserializer', common.mustCall(() => {
 oversizedLengthHeader,
  ...chunks,
 ]);
-assert.deepStrictEqual(reported.at(-1),diagnosticEvent);
+assert.deepStrictEqual(reported.at(-1),reportedDiagnosticEvent);
 assert.strictEqual(reported.filter((event)=>event.type==='test:diagnostic').length,1);
 assert.strictEqual(collectStdout(reported),oversizedLengthStdout);
 });
@@ -152,7 +158,7 @@ describe('v8 deserializer', common.mustCall(() => {
 constdata=chunks[0];
 constreported=awaitcollectReported([data.subarray(0,i),data.subarray(i)]);
 assert.deepStrictEqual(reported,[
-diagnosticEvent,
+reportedDiagnosticEvent,
 ]);
 });
 
@@ -163,9 +169,9 @@ describe('v8 deserializer', common.mustCall(() => {
 Buffer.concat([data.subarray(i),Buffer.from('unknown')]),
 ]);
 assert.deepStrictEqual(reported,[
-{data: {__proto__: null,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
-diagnosticEvent,
-{data: {__proto__: null,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
+{data: {__proto__: null,entryFile,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
+reportedDiagnosticEvent,
+{data: {__proto__: null,entryFile,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
 ]);
 }
 );

doc/api/test.md

@@ -3430,6 +3430,10 @@ added:
  - v18.9.0
  - v16.19.0
 changes:
+ - version: REPLACEME
+ pr-url: https://github.com/nodejs/node/pull/64309
+ description: Added `entryFile` to events forwarded from child processes
+ when tests run with process isolation.
  - version: v24.19.0
  pr-url: https://github.com/nodejs/node/pull/63435
  description: Added `parentId` to test events that carry a `testId`.
@@ -3514,6 +3518,10 @@ Emitted when code coverage is enabled and all tests have completed.
 *`cause` {Error} The actual error thrown by the test.
 *`type` {string|undefined} The type of the test, used to denote whether
  this is a suite.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3543,6 +3551,10 @@ The corresponding declaration ordered events are `'test:pass'` and `'test:fail'`
 *`data` {Object}
 *`column` {number|undefined} The column number where the test is defined, or
 `undefined` if the test was run through the REPL.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3569,6 +3581,10 @@ defined. The corresponding declaration ordered event is `'test:start'`.
 *`data` {Object}
 *`column` {number|undefined} The column number where the test is defined, or
 `undefined` if the test was run through the REPL.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3590,6 +3606,10 @@ defined.
 *`data` {Object}
 *`column` {number|undefined} The column number where the test is defined, or
 `undefined` if the test was run through the REPL.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3622,6 +3642,10 @@ Emitted when a test is enqueued for execution.
  this is a suite.
 *`attempt` {number|undefined} The attempt number of the test run,
  present only when using the [`--test-rerun-failures`][] flag.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3685,6 +3709,10 @@ since the parent runner only knows about file-level tests. When using
  present only when using the [`--test-rerun-failures`][] flag.
 *`passed_on_attempt` {number|undefined} The attempt number the test passed on,
  present only when using the [`--test-rerun-failures`][] flag.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3714,6 +3742,10 @@ The corresponding execution ordered event is `'test:complete'`.
 *`data` {Object}
 *`column` {number|undefined} The column number where the test is defined, or
 `undefined` if the test was run through the REPL.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3730,6 +3762,10 @@ defined.
 *`data` {Object}
 *`column` {number|undefined} The column number where the test is defined, or
 `undefined` if the test was run through the REPL.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3754,6 +3790,9 @@ The corresponding execution ordered event is `'test:dequeue'`.
 ### Event: `'test:stderr'`
 
 *`data` {Object}
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation.
 *`file` {string} The path of the test file.
 *`message` {string} The message written to `stderr`.
 
@@ -3765,6 +3804,9 @@ defined.
 ### Event: `'test:stdout'`
 
 *`data` {Object}
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation.
 *`file` {string} The path of the test file.
 *`message` {string} The message written to `stdout`.
 

lib/internal/test_runner/runner.js

@@ -295,6 +295,10 @@ class FileTest extends Test {
 ArrayPrototypeIncludes(kDiagnosticsFilterArgs,StringPrototypeSlice(comment,0,firstSpaceIndex));
 }
  #handleReportItem(item){
+// The name is empty when a single child process runs all test files.
+if(this.name!==''){
+item.data.entryFile=this.loc.file;
+}
 constisTopLevel=item.data.nesting===0;
 if(isTopLevel){
 if(item.type==='test:plan'&&this.#skipReporting()){

test/fixtures/test-runner/entry-file/a.test.mjs

@@ -0,0 +1,3 @@
+import{test}from'node:test';
+import{runShared}from'./helper.mjs';
+test('backup A',async(t)=>{awaitrunShared(t,'A');});

test/fixtures/test-runner/entry-file/b.test.mjs

@@ -0,0 +1,3 @@
+import{test}from'node:test';
+import{runShared}from'./helper.mjs';
+test('backup B',async(t)=>{awaitrunShared(t,'B');});

test/fixtures/test-runner/entry-file/helper.mjs

@@ -0,0 +1,3 @@
+exportasyncfunctionrunShared(t,target){
+awaitt.test(`restore ${target}`,async()=>{});
+}

test/parallel/test-runner-entry-file.mjs

@@ -0,0 +1,59 @@
+import'../common/index.mjs';
+import*asfixturesfrom'../common/fixtures.mjs';
+import{describe,it,run}from'node:test';
+importassertfrom'node:assert';
+
+constaPath=fixtures.path('test-runner','entry-file','a.test.mjs');
+constbPath=fixtures.path('test-runner','entry-file','b.test.mjs');
+consthelperPath=fixtures.path('test-runner','entry-file','helper.mjs');
+
+asyncfunctioncollectEvents(options){
+constevents=[];
+conststream=run({files: [aPath,bPath], ...options});
+stream.on('test:fail',()=>{});
+forawait(consteventofstream){
+events.push(event);
+}
+returnevents;
+}
+
+describe('entryFile attribution in reporter events',{concurrency: false},()=>{
+it('stamps entryFile on events forwarded from child processes',async()=>{
+constevents=awaitcollectEvents({isolation: 'process'});
+constchecked={__proto__: null,A: 0,B: 0};
+
+for(const{ type, data }ofevents){
+if(data?.name==='restore A'||data?.name==='restore B'){
+consttarget=data.name==='restore A' ? 'A' : 'B';
+constexpectedEntry=target==='A' ? aPath : bPath;
+assert.strictEqual(data.file,helperPath,
+`${type} file should be the definition site`);
+assert.strictEqual(data.entryFile,expectedEntry,
+`${type} entryFile should be the entry file`);
+checked[target]++;
+}
+}
+
+// Each subtest emits at least enqueue/dequeue/start/pass/complete.
+assert.ok(checked.A>=4,`expected events for restore A, got ${checked.A}`);
+assert.ok(checked.B>=4,`expected events for restore B, got ${checked.B}`);
+});
+
+it('stamps entryFile on top-level tests forwarded from child processes',async()=>{
+constevents=awaitcollectEvents({isolation: 'process'});
+constpass=events.filter(({ type })=>type==='test:pass');
+constbackupA=pass.find(({ data })=>data.name==='backup A');
+constbackupB=pass.find(({ data })=>data.name==='backup B');
+assert.strictEqual(backupA.data.entryFile,aPath);
+assert.strictEqual(backupB.data.entryFile,bPath);
+});
+
+it('does not stamp entryFile with isolation none',async()=>{
+constevents=awaitcollectEvents({isolation: 'none'});
+for(const{ data }ofevents){
+if(data?.name==='restore A'||data?.name==='restore B'){
+assert.strictEqual(data.entryFile,undefined);
+}
+}
+});
+});

test/parallel/test-runner-v8-deserializer.mjs

@@ -5,6 +5,7 @@ import { describe, it, beforeEach } from 'node:test';
 importassertfrom'node:assert';
 import{finished}from'node:stream/promises';
 import{DefaultSerializer}from'node:v8';
+import{resolve}from'node:path';
 importserializerfrom'internal/test_runner/reporter/v8-serializer';
 importrunnerfrom'internal/test_runner/runner';
 
@@ -14,10 +15,15 @@ async function toArray(chunks) {
 returnarr;
 }
 
+constentryFile=resolve('filetest');
 constdiagnosticEvent={
 type: 'test:diagnostic',
 data: {nesting: 0,details: {},message: 'diagnostic'},
 };
+constreportedDiagnosticEvent={
+type: 'test:diagnostic',
+data: { ...diagnosticEvent.data, entryFile },
+};
 constchunks=awaittoArray(serializer([diagnosticEvent]));
 constdefaultSerializer=newDefaultSerializer();
 defaultSerializer.writeHeader();
@@ -67,28 +73,28 @@ describe('v8 deserializer', common.mustCall(() => {
 it('should deserialize a chunk with no serialization',async()=>{
 constreported=awaitcollectReported([Buffer.from('unknown')]);
 assert.deepStrictEqual(reported,[
-{data: {__proto__: null,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
+{data: {__proto__: null,entryFile,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
 ]);
 });
 
 it('should deserialize a serialized chunk',async()=>{
 constreported=awaitcollectReported(chunks);
-assert.deepStrictEqual(reported,[diagnosticEvent]);
+assert.deepStrictEqual(reported,[reportedDiagnosticEvent]);
 });
 
 it('should deserialize a serialized chunk after non-serialized chunk',async()=>{
 constreported=awaitcollectReported([Buffer.concat([Buffer.from('unknown'), ...chunks])]);
 assert.deepStrictEqual(reported,[
-{data: {__proto__: null,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
-diagnosticEvent,
+{data: {__proto__: null,entryFile,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
+reportedDiagnosticEvent,
 ]);
 });
 
 it('should deserialize a serialized chunk before non-serialized output',async()=>{
 constreported=awaitcollectReported([Buffer.concat([ ...chunks,Buffer.from('unknown')])]);
 assert.deepStrictEqual(reported,[
-diagnosticEvent,
-{data: {__proto__: null,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
+reportedDiagnosticEvent,
+{data: {__proto__: null,entryFile,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
 ]);
 });
 
@@ -131,7 +137,7 @@ describe('v8 deserializer', common.mustCall(() => {
 oversizedLengthHeader,
  ...chunks,
 ]);
-assert.deepStrictEqual(reported.at(-1),diagnosticEvent);
+assert.deepStrictEqual(reported.at(-1),reportedDiagnosticEvent);
 assert.strictEqual(reported.filter((event)=>event.type==='test:diagnostic').length,1);
 assert.strictEqual(collectStdout(reported),oversizedLengthStdout);
 });
@@ -152,7 +158,7 @@ describe('v8 deserializer', common.mustCall(() => {
 constdata=chunks[0];
 constreported=awaitcollectReported([data.subarray(0,i),data.subarray(i)]);
 assert.deepStrictEqual(reported,[
-diagnosticEvent,
+reportedDiagnosticEvent,
 ]);
 });
 
@@ -163,9 +169,9 @@ describe('v8 deserializer', common.mustCall(() => {
 Buffer.concat([data.subarray(i),Buffer.from('unknown')]),
 ]);
 assert.deepStrictEqual(reported,[
-{data: {__proto__: null,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
-diagnosticEvent,
-{data: {__proto__: null,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
+{data: {__proto__: null,entryFile,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
+reportedDiagnosticEvent,
+{data: {__proto__: null,entryFile,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
 ]);
 }
 );

doc/api/test.md

@@ -3430,6 +3430,10 @@ added:
  - v18.9.0
  - v16.19.0
 changes:
+ - version: REPLACEME
+ pr-url: https://github.com/nodejs/node/pull/64309
+ description: Added `entryFile` to events forwarded from child processes
+ when tests run with process isolation.
  - version: v24.19.0
  pr-url: https://github.com/nodejs/node/pull/63435
  description: Added `parentId` to test events that carry a `testId`.
@@ -3514,6 +3518,10 @@ Emitted when code coverage is enabled and all tests have completed.
 *`cause` {Error} The actual error thrown by the test.
 *`type` {string|undefined} The type of the test, used to denote whether
  this is a suite.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3543,6 +3551,10 @@ The corresponding declaration ordered events are `'test:pass'` and `'test:fail'`
 *`data` {Object}
 *`column` {number|undefined} The column number where the test is defined, or
 `undefined` if the test was run through the REPL.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3569,6 +3581,10 @@ defined. The corresponding declaration ordered event is `'test:start'`.
 *`data` {Object}
 *`column` {number|undefined} The column number where the test is defined, or
 `undefined` if the test was run through the REPL.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3590,6 +3606,10 @@ defined.
 *`data` {Object}
 *`column` {number|undefined} The column number where the test is defined, or
 `undefined` if the test was run through the REPL.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3622,6 +3642,10 @@ Emitted when a test is enqueued for execution.
  this is a suite.
 *`attempt` {number|undefined} The attempt number of the test run,
  present only when using the [`--test-rerun-failures`][] flag.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3685,6 +3709,10 @@ since the parent runner only knows about file-level tests. When using
  present only when using the [`--test-rerun-failures`][] flag.
 *`passed_on_attempt` {number|undefined} The attempt number the test passed on,
  present only when using the [`--test-rerun-failures`][] flag.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3714,6 +3742,10 @@ The corresponding execution ordered event is `'test:complete'`.
 *`data` {Object}
 *`column` {number|undefined} The column number where the test is defined, or
 `undefined` if the test was run through the REPL.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3730,6 +3762,10 @@ defined.
 *`data` {Object}
 *`column` {number|undefined} The column number where the test is defined, or
 `undefined` if the test was run through the REPL.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3754,6 +3790,9 @@ The corresponding execution ordered event is `'test:dequeue'`.
 ### Event: `'test:stderr'`
 
 *`data` {Object}
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation.
 *`file` {string} The path of the test file.
 *`message` {string} The message written to `stderr`.
 
@@ -3765,6 +3804,9 @@ defined.
 ### Event: `'test:stdout'`
 
 *`data` {Object}
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation.
 *`file` {string} The path of the test file.
 *`message` {string} The message written to `stdout`.
 

lib/internal/test_runner/runner.js

@@ -295,6 +295,10 @@ class FileTest extends Test {
 ArrayPrototypeIncludes(kDiagnosticsFilterArgs,StringPrototypeSlice(comment,0,firstSpaceIndex));
 }
  #handleReportItem(item){
+// The name is empty when a single child process runs all test files.
+if(this.name!==''){
+item.data.entryFile=this.loc.file;
+}
 constisTopLevel=item.data.nesting===0;
 if(isTopLevel){
 if(item.type==='test:plan'&&this.#skipReporting()){

test/fixtures/test-runner/entry-file/a.test.mjs

@@ -0,0 +1,3 @@
+import{test}from'node:test';
+import{runShared}from'./helper.mjs';
+test('backup A',async(t)=>{awaitrunShared(t,'A');});

test/fixtures/test-runner/entry-file/b.test.mjs

@@ -0,0 +1,3 @@
+import{test}from'node:test';
+import{runShared}from'./helper.mjs';
+test('backup B',async(t)=>{awaitrunShared(t,'B');});

test/fixtures/test-runner/entry-file/helper.mjs

@@ -0,0 +1,3 @@
+exportasyncfunctionrunShared(t,target){
+awaitt.test(`restore ${target}`,async()=>{});
+}

test/parallel/test-runner-entry-file.mjs

@@ -0,0 +1,59 @@
+import'../common/index.mjs';
+import*asfixturesfrom'../common/fixtures.mjs';
+import{describe,it,run}from'node:test';
+importassertfrom'node:assert';
+
+constaPath=fixtures.path('test-runner','entry-file','a.test.mjs');
+constbPath=fixtures.path('test-runner','entry-file','b.test.mjs');
+consthelperPath=fixtures.path('test-runner','entry-file','helper.mjs');
+
+asyncfunctioncollectEvents(options){
+constevents=[];
+conststream=run({files: [aPath,bPath], ...options});
+stream.on('test:fail',()=>{});
+forawait(consteventofstream){
+events.push(event);
+}
+returnevents;
+}
+
+describe('entryFile attribution in reporter events',{concurrency: false},()=>{
+it('stamps entryFile on events forwarded from child processes',async()=>{
+constevents=awaitcollectEvents({isolation: 'process'});
+constchecked={__proto__: null,A: 0,B: 0};
+
+for(const{ type, data }ofevents){
+if(data?.name==='restore A'||data?.name==='restore B'){
+consttarget=data.name==='restore A' ? 'A' : 'B';
+constexpectedEntry=target==='A' ? aPath : bPath;
+assert.strictEqual(data.file,helperPath,
+`${type} file should be the definition site`);
+assert.strictEqual(data.entryFile,expectedEntry,
+`${type} entryFile should be the entry file`);
+checked[target]++;
+}
+}
+
+// Each subtest emits at least enqueue/dequeue/start/pass/complete.
+assert.ok(checked.A>=4,`expected events for restore A, got ${checked.A}`);
+assert.ok(checked.B>=4,`expected events for restore B, got ${checked.B}`);
+});
+
+it('stamps entryFile on top-level tests forwarded from child processes',async()=>{
+constevents=awaitcollectEvents({isolation: 'process'});
+constpass=events.filter(({ type })=>type==='test:pass');
+constbackupA=pass.find(({ data })=>data.name==='backup A');
+constbackupB=pass.find(({ data })=>data.name==='backup B');
+assert.strictEqual(backupA.data.entryFile,aPath);
+assert.strictEqual(backupB.data.entryFile,bPath);
+});
+
+it('does not stamp entryFile with isolation none',async()=>{
+constevents=awaitcollectEvents({isolation: 'none'});
+for(const{ data }ofevents){
+if(data?.name==='restore A'||data?.name==='restore B'){
+assert.strictEqual(data.entryFile,undefined);
+}
+}
+});
+});

test/parallel/test-runner-v8-deserializer.mjs

@@ -5,6 +5,7 @@ import { describe, it, beforeEach } from 'node:test';
 importassertfrom'node:assert';
 import{finished}from'node:stream/promises';
 import{DefaultSerializer}from'node:v8';
+import{resolve}from'node:path';
 importserializerfrom'internal/test_runner/reporter/v8-serializer';
 importrunnerfrom'internal/test_runner/runner';
 
@@ -14,10 +15,15 @@ async function toArray(chunks) {
 returnarr;
 }
 
+constentryFile=resolve('filetest');
 constdiagnosticEvent={
 type: 'test:diagnostic',
 data: {nesting: 0,details: {},message: 'diagnostic'},
 };
+constreportedDiagnosticEvent={
+type: 'test:diagnostic',
+data: { ...diagnosticEvent.data, entryFile },
+};
 constchunks=awaittoArray(serializer([diagnosticEvent]));
 constdefaultSerializer=newDefaultSerializer();
 defaultSerializer.writeHeader();
@@ -67,28 +73,28 @@ describe('v8 deserializer', common.mustCall(() => {
 it('should deserialize a chunk with no serialization',async()=>{
 constreported=awaitcollectReported([Buffer.from('unknown')]);
 assert.deepStrictEqual(reported,[
-{data: {__proto__: null,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
+{data: {__proto__: null,entryFile,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
 ]);
 });
 
 it('should deserialize a serialized chunk',async()=>{
 constreported=awaitcollectReported(chunks);
-assert.deepStrictEqual(reported,[diagnosticEvent]);
+assert.deepStrictEqual(reported,[reportedDiagnosticEvent]);
 });
 
 it('should deserialize a serialized chunk after non-serialized chunk',async()=>{
 constreported=awaitcollectReported([Buffer.concat([Buffer.from('unknown'), ...chunks])]);
 assert.deepStrictEqual(reported,[
-{data: {__proto__: null,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
-diagnosticEvent,
+{data: {__proto__: null,entryFile,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
+reportedDiagnosticEvent,
 ]);
 });
 
 it('should deserialize a serialized chunk before non-serialized output',async()=>{
 constreported=awaitcollectReported([Buffer.concat([ ...chunks,Buffer.from('unknown')])]);
 assert.deepStrictEqual(reported,[
-diagnosticEvent,
-{data: {__proto__: null,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
+reportedDiagnosticEvent,
+{data: {__proto__: null,entryFile,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
 ]);
 });
 
@@ -131,7 +137,7 @@ describe('v8 deserializer', common.mustCall(() => {
 oversizedLengthHeader,
  ...chunks,
 ]);
-assert.deepStrictEqual(reported.at(-1),diagnosticEvent);
+assert.deepStrictEqual(reported.at(-1),reportedDiagnosticEvent);
 assert.strictEqual(reported.filter((event)=>event.type==='test:diagnostic').length,1);
 assert.strictEqual(collectStdout(reported),oversizedLengthStdout);
 });
@@ -152,7 +158,7 @@ describe('v8 deserializer', common.mustCall(() => {
 constdata=chunks[0];
 constreported=awaitcollectReported([data.subarray(0,i),data.subarray(i)]);
 assert.deepStrictEqual(reported,[
-diagnosticEvent,
+reportedDiagnosticEvent,
 ]);
 });
 
@@ -163,9 +169,9 @@ describe('v8 deserializer', common.mustCall(() => {
 Buffer.concat([data.subarray(i),Buffer.from('unknown')]),
 ]);
 assert.deepStrictEqual(reported,[
-{data: {__proto__: null,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
-diagnosticEvent,
-{data: {__proto__: null,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
+{data: {__proto__: null,entryFile,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
+reportedDiagnosticEvent,
+{data: {__proto__: null,entryFile,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
 ]);
 }
 );

doc/api/test.md

@@ -3430,6 +3430,10 @@ added:
  - v18.9.0
  - v16.19.0
 changes:
+ - version: REPLACEME
+ pr-url: https://github.com/nodejs/node/pull/64309
+ description: Added `entryFile` to events forwarded from child processes
+ when tests run with process isolation.
  - version: v24.19.0
  pr-url: https://github.com/nodejs/node/pull/63435
  description: Added `parentId` to test events that carry a `testId`.
@@ -3514,6 +3518,10 @@ Emitted when code coverage is enabled and all tests have completed.
 *`cause` {Error} The actual error thrown by the test.
 *`type` {string|undefined} The type of the test, used to denote whether
  this is a suite.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3543,6 +3551,10 @@ The corresponding declaration ordered events are `'test:pass'` and `'test:fail'`
 *`data` {Object}
 *`column` {number|undefined} The column number where the test is defined, or
 `undefined` if the test was run through the REPL.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3569,6 +3581,10 @@ defined. The corresponding declaration ordered event is `'test:start'`.
 *`data` {Object}
 *`column` {number|undefined} The column number where the test is defined, or
 `undefined` if the test was run through the REPL.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3590,6 +3606,10 @@ defined.
 *`data` {Object}
 *`column` {number|undefined} The column number where the test is defined, or
 `undefined` if the test was run through the REPL.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3622,6 +3642,10 @@ Emitted when a test is enqueued for execution.
  this is a suite.
 *`attempt` {number|undefined} The attempt number of the test run,
  present only when using the [`--test-rerun-failures`][] flag.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3685,6 +3709,10 @@ since the parent runner only knows about file-level tests. When using
  present only when using the [`--test-rerun-failures`][] flag.
 *`passed_on_attempt` {number|undefined} The attempt number the test passed on,
  present only when using the [`--test-rerun-failures`][] flag.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3714,6 +3742,10 @@ The corresponding execution ordered event is `'test:complete'`.
 *`data` {Object}
 *`column` {number|undefined} The column number where the test is defined, or
 `undefined` if the test was run through the REPL.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3730,6 +3762,10 @@ defined.
 *`data` {Object}
 *`column` {number|undefined} The column number where the test is defined, or
 `undefined` if the test was run through the REPL.
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation. May differ from
+`file` when the test is defined in a module imported by the entry file.
 *`file` {string|undefined} The path of the test file,
 `undefined` if test was run through the REPL.
 *`line` {number|undefined} The line number where the test is defined, or
@@ -3754,6 +3790,9 @@ The corresponding execution ordered event is `'test:dequeue'`.
 ### Event: `'test:stderr'`
 
 *`data` {Object}
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation.
 *`file` {string} The path of the test file.
 *`message` {string} The message written to `stderr`.
 
@@ -3765,6 +3804,9 @@ defined.
 ### Event: `'test:stdout'`
 
 *`data` {Object}
+*`entryFile` {string|undefined} The path of the test file that was
+ executed as the entry point of the child process that emitted this event.
+ Only present when tests run with process isolation.
 *`file` {string} The path of the test file.
 *`message` {string} The message written to `stdout`.
 

lib/internal/test_runner/runner.js

@@ -295,6 +295,10 @@ class FileTest extends Test {
 ArrayPrototypeIncludes(kDiagnosticsFilterArgs,StringPrototypeSlice(comment,0,firstSpaceIndex));
 }
  #handleReportItem(item){
+// The name is empty when a single child process runs all test files.
+if(this.name!==''){
+item.data.entryFile=this.loc.file;
+}
 constisTopLevel=item.data.nesting===0;
 if(isTopLevel){
 if(item.type==='test:plan'&&this.#skipReporting()){

test/fixtures/test-runner/entry-file/a.test.mjs

@@ -0,0 +1,3 @@
+import{test}from'node:test';
+import{runShared}from'./helper.mjs';
+test('backup A',async(t)=>{awaitrunShared(t,'A');});

test/fixtures/test-runner/entry-file/b.test.mjs

@@ -0,0 +1,3 @@
+import{test}from'node:test';
+import{runShared}from'./helper.mjs';
+test('backup B',async(t)=>{awaitrunShared(t,'B');});

test/fixtures/test-runner/entry-file/helper.mjs

@@ -0,0 +1,3 @@
+exportasyncfunctionrunShared(t,target){
+awaitt.test(`restore ${target}`,async()=>{});
+}

test/parallel/test-runner-entry-file.mjs

@@ -0,0 +1,59 @@
+import'../common/index.mjs';
+import*asfixturesfrom'../common/fixtures.mjs';
+import{describe,it,run}from'node:test';
+importassertfrom'node:assert';
+
+constaPath=fixtures.path('test-runner','entry-file','a.test.mjs');
+constbPath=fixtures.path('test-runner','entry-file','b.test.mjs');
+consthelperPath=fixtures.path('test-runner','entry-file','helper.mjs');
+
+asyncfunctioncollectEvents(options){
+constevents=[];
+conststream=run({files: [aPath,bPath], ...options});
+stream.on('test:fail',()=>{});
+forawait(consteventofstream){
+events.push(event);
+}
+returnevents;
+}
+
+describe('entryFile attribution in reporter events',{concurrency: false},()=>{
+it('stamps entryFile on events forwarded from child processes',async()=>{
+constevents=awaitcollectEvents({isolation: 'process'});
+constchecked={__proto__: null,A: 0,B: 0};
+
+for(const{ type, data }ofevents){
+if(data?.name==='restore A'||data?.name==='restore B'){
+consttarget=data.name==='restore A' ? 'A' : 'B';
+constexpectedEntry=target==='A' ? aPath : bPath;
+assert.strictEqual(data.file,helperPath,
+`${type} file should be the definition site`);
+assert.strictEqual(data.entryFile,expectedEntry,
+`${type} entryFile should be the entry file`);
+checked[target]++;
+}
+}
+
+// Each subtest emits at least enqueue/dequeue/start/pass/complete.
+assert.ok(checked.A>=4,`expected events for restore A, got ${checked.A}`);
+assert.ok(checked.B>=4,`expected events for restore B, got ${checked.B}`);
+});
+
+it('stamps entryFile on top-level tests forwarded from child processes',async()=>{
+constevents=awaitcollectEvents({isolation: 'process'});
+constpass=events.filter(({ type })=>type==='test:pass');
+constbackupA=pass.find(({ data })=>data.name==='backup A');
+constbackupB=pass.find(({ data })=>data.name==='backup B');
+assert.strictEqual(backupA.data.entryFile,aPath);
+assert.strictEqual(backupB.data.entryFile,bPath);
+});
+
+it('does not stamp entryFile with isolation none',async()=>{
+constevents=awaitcollectEvents({isolation: 'none'});
+for(const{ data }ofevents){
+if(data?.name==='restore A'||data?.name==='restore B'){
+assert.strictEqual(data.entryFile,undefined);
+}
+}
+});
+});

test/parallel/test-runner-v8-deserializer.mjs

@@ -5,6 +5,7 @@ import { describe, it, beforeEach } from 'node:test';
 importassertfrom'node:assert';
 import{finished}from'node:stream/promises';
 import{DefaultSerializer}from'node:v8';
+import{resolve}from'node:path';
 importserializerfrom'internal/test_runner/reporter/v8-serializer';
 importrunnerfrom'internal/test_runner/runner';
 
@@ -14,10 +15,15 @@ async function toArray(chunks) {
 returnarr;
 }
 
+constentryFile=resolve('filetest');
 constdiagnosticEvent={
 type: 'test:diagnostic',
 data: {nesting: 0,details: {},message: 'diagnostic'},
 };
+constreportedDiagnosticEvent={
+type: 'test:diagnostic',
+data: { ...diagnosticEvent.data, entryFile },
+};
 constchunks=awaittoArray(serializer([diagnosticEvent]));
 constdefaultSerializer=newDefaultSerializer();
 defaultSerializer.writeHeader();
@@ -67,28 +73,28 @@ describe('v8 deserializer', common.mustCall(() => {
 it('should deserialize a chunk with no serialization',async()=>{
 constreported=awaitcollectReported([Buffer.from('unknown')]);
 assert.deepStrictEqual(reported,[
-{data: {__proto__: null,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
+{data: {__proto__: null,entryFile,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
 ]);
 });
 
 it('should deserialize a serialized chunk',async()=>{
 constreported=awaitcollectReported(chunks);
-assert.deepStrictEqual(reported,[diagnosticEvent]);
+assert.deepStrictEqual(reported,[reportedDiagnosticEvent]);
 });
 
 it('should deserialize a serialized chunk after non-serialized chunk',async()=>{
 constreported=awaitcollectReported([Buffer.concat([Buffer.from('unknown'), ...chunks])]);
 assert.deepStrictEqual(reported,[
-{data: {__proto__: null,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
-diagnosticEvent,
+{data: {__proto__: null,entryFile,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
+reportedDiagnosticEvent,
 ]);
 });
 
 it('should deserialize a serialized chunk before non-serialized output',async()=>{
 constreported=awaitcollectReported([Buffer.concat([ ...chunks,Buffer.from('unknown')])]);
 assert.deepStrictEqual(reported,[
-diagnosticEvent,
-{data: {__proto__: null,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
+reportedDiagnosticEvent,
+{data: {__proto__: null,entryFile,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
 ]);
 });
 
@@ -131,7 +137,7 @@ describe('v8 deserializer', common.mustCall(() => {
 oversizedLengthHeader,
  ...chunks,
 ]);
-assert.deepStrictEqual(reported.at(-1),diagnosticEvent);
+assert.deepStrictEqual(reported.at(-1),reportedDiagnosticEvent);
 assert.strictEqual(reported.filter((event)=>event.type==='test:diagnostic').length,1);
 assert.strictEqual(collectStdout(reported),oversizedLengthStdout);
 });
@@ -152,7 +158,7 @@ describe('v8 deserializer', common.mustCall(() => {
 constdata=chunks[0];
 constreported=awaitcollectReported([data.subarray(0,i),data.subarray(i)]);
 assert.deepStrictEqual(reported,[
-diagnosticEvent,
+reportedDiagnosticEvent,
 ]);
 });
 
@@ -163,9 +169,9 @@ describe('v8 deserializer', common.mustCall(() => {
 Buffer.concat([data.subarray(i),Buffer.from('unknown')]),
 ]);
 assert.deepStrictEqual(reported,[
-{data: {__proto__: null,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
-diagnosticEvent,
-{data: {__proto__: null,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
+{data: {__proto__: null,entryFile,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
+reportedDiagnosticEvent,
+{data: {__proto__: null,entryFile,file: 'filetest',message: 'unknown'},type: 'test:stdout'},
 ]);
 }
 );