test_runner: add 'test:summary' event

This commit adds a new 'test:summary' event to the test runner's
reporting interface. This new event serves two purposes:

- In the future, the test runner internals will no longer need to
  change the process exit code. This may be important to run()
  users. Unfortunately, this is a breaking change, so it needs to
  be changed in a major version.
- The reporting interface now has a single event that can identify
  passing or failing test runs.

Refs: https://github.com/nodejs/node/issues/53867
Refs: https://github.com/nodejs/node/issues/54812
PR-URL: https://github.com/nodejs/node/pull/54851
Reviewed-By: Chemi Atlow <chemi@atlow.co.il>
Reviewed-By: Moshe Atlow <moshe@atlow.co.il>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>

doc/api/test.md

@@ -3042,6 +3042,31 @@ This event is only emitted if `--test` flag is passed.
 This event is not guaranteed to be emitted in the same order as the tests are
 defined.
 
+### Event: `'test:summary'`
+
+* `data` {Object}
+  * `counts` {Object} An object containing the counts of various test results.
+    * `cancelled` {number} The total number of cancelled tests.
+    * `failed` {number} The total number of failed tests.
+    * `passed` {number} The total number of passed tests.
+    * `skipped` {number} The total number of skipped tests.
+    * `suites` {number} The total number of suites run.
+    * `tests` {number} The total number of tests run, excluding suites.
+    * `todo` {number} The total number of TODO tests.
+    * `topLevel` {number} The total number of top level tests and suites.
+  * `duration_ms` {number} The duration of the test run in milliseconds.
+  * `file` {string|undefined} The path of the test file that generated the
+    summary. If the summary corresponds to multiple files, this value is
+    `undefined`.
+  * `success` {boolean} Indicates whether or not the test run is considered
+    successful or not. If any error condition occurs, such as a failing test or
+    unmet coverage threshold, this value will be set to `false`.
+
+Emitted when a test run completes. This event contains metrics pertaining to
+the completed test run, and is useful for determining if a test run passed or
+failed. If process-level test isolation is used, a `'test:summary'` event is
+generated for each test file in addition to a final cumulative summary.
+
 ### Event: `'test:watch:drained'`
 
 Emitted when no more tests are queued for execution in watch mode.

lib/internal/main/test_runner.js

@@ -31,8 +31,8 @@ if (isUsingInspector() && options.isolation === 'process') {
 options.globPatterns = ArrayPrototypeSlice(process.argv, 1);
 
 debug('test runner configuration:', options);
-run(options).on('test:fail', (data) => {
-  if (data.todo === undefined || data.todo === false) {
+run(options).on('test:summary', (data) => {
+  if (!data.success) {
     process.exitCode = kGenericUserError;
   }
 });

lib/internal/test_runner/harness.js

@@ -52,7 +52,7 @@ function createTestTree(rootTestOptions, globalOptions) {
     resetCounters() {
       harness.counters = {
         __proto__: null,
-        all: 0,
+        tests: 0,
         failed: 0,
         passed: 0,
         cancelled: 0,
@@ -62,6 +62,7 @@ function createTestTree(rootTestOptions, globalOptions) {
         suites: 0,
       };
     },
+    success: true,
     counters: null,
     shouldColorizeTestFiles: shouldColorizeTestFiles(globalOptions.destinations),
     teardown: null,
@@ -130,6 +131,7 @@ function createProcessEventHandler(eventName, rootTest) {
       }
 
       rootTest.diagnostic(msg);
+      rootTest.harness.success = false;
       process.exitCode = kGenericUserError;
       return;
     }
@@ -152,6 +154,7 @@ function configureCoverage(rootTest, globalOptions) {
     const msg = `Warning: Code coverage could not be enabled. ${err}`;
 
     rootTest.diagnostic(msg);
+    rootTest.harness.success = false;
     process.exitCode = kGenericUserError;
   }
 }
@@ -167,6 +170,7 @@ function collectCoverage(rootTest, coverage) {
     summary = coverage.summary();
   } catch (err) {
     rootTest.diagnostic(`Warning: Could not report code coverage. ${err}`);
+    rootTest.harness.success = false;
     process.exitCode = kGenericUserError;
   }
 
@@ -174,6 +178,7 @@ function collectCoverage(rootTest, coverage) {
     coverage.cleanup();
   } catch (err) {
     rootTest.diagnostic(`Warning: Could not clean up code coverage. ${err}`);
+    rootTest.harness.success = false;
     process.exitCode = kGenericUserError;
   }
 
@@ -248,14 +253,16 @@ function lazyBootstrapRoot() {
   if (!globalRoot) {
     // This is where the test runner is bootstrapped when node:test is used
     // without the --test flag or the run() API.
+    const entryFile = process.argv?.[1];
     const rootTestOptions = {
       __proto__: null,
-      entryFile: process.argv?.[1],
+      entryFile,
+      loc: entryFile ? [1, 1, entryFile] : undefined,
     };
     const globalOptions = parseCommandLine();
     createTestTree(rootTestOptions, globalOptions);
-    globalRoot.reporter.on('test:fail', (data) => {
-      if (data.todo === undefined || data.todo === false) {
+    globalRoot.reporter.on('test:summary', (data) => {
+      if (!data.success) {
         process.exitCode = kGenericUserError;
       }
     });

lib/internal/test_runner/test.js

@@ -1043,14 +1043,15 @@ class Test extends AsyncResource {
         reporter.diagnostic(nesting, loc, diagnostics[i]);
       }
 
-      reporter.diagnostic(nesting, loc, `tests ${harness.counters.all}`);
+      const duration = this.duration();
+      reporter.diagnostic(nesting, loc, `tests ${harness.counters.tests}`);
       reporter.diagnostic(nesting, loc, `suites ${harness.counters.suites}`);
       reporter.diagnostic(nesting, loc, `pass ${harness.counters.passed}`);
       reporter.diagnostic(nesting, loc, `fail ${harness.counters.failed}`);
       reporter.diagnostic(nesting, loc, `cancelled ${harness.counters.cancelled}`);
       reporter.diagnostic(nesting, loc, `skipped ${harness.counters.skipped}`);
       reporter.diagnostic(nesting, loc, `todo ${harness.counters.todo}`);
-      reporter.diagnostic(nesting, loc, `duration_ms ${this.duration()}`);
+      reporter.diagnostic(nesting, loc, `duration_ms ${duration}`);
 
       if (coverage) {
         const coverages = [
@@ -1067,6 +1068,7 @@ class Test extends AsyncResource {
         for (let i = 0; i < coverages.length; i++) {
           const { threshold, actual, name } = coverages[i];
           if (actual < threshold) {
+            harness.success = false;
             process.exitCode = kGenericUserError;
             reporter.diagnostic(nesting, loc, `Error: ${NumberPrototypeToFixed(actual, 2)}% ${name} coverage does not meet threshold of ${threshold}%.`);
           }
@@ -1075,6 +1077,10 @@ class Test extends AsyncResource {
         reporter.coverage(nesting, loc, coverage);
       }
 
+      reporter.summary(
+        nesting, loc?.file, harness.success, harness.counters, duration,
+      );
+
       if (harness.watching) {
         this.reported = false;
         harness.resetCounters();

lib/internal/test_runner/tests_stream.js

@@ -132,6 +132,16 @@ class TestsStream extends Readable {
     });
   }
 
+  summary(nesting, file, success, counts, duration_ms) {
+    this[kEmitMessage]('test:summary', {
+      __proto__: null,
+      success,
+      counts,
+      duration_ms,
+      file,
+    });
+  }
+
   end() {
     this.#tryPush(null);
   }

lib/internal/test_runner/utils.js

@@ -357,12 +357,14 @@ function countCompletedTest(test, harness = test.root.harness) {
     harness.counters.todo++;
   } else if (test.cancelled) {
     harness.counters.cancelled++;
+    harness.success = false;
   } else if (!test.passed) {
     harness.counters.failed++;
+    harness.success = false;
   } else {
     harness.counters.passed++;
   }
-  harness.counters.all++;
+  harness.counters.tests++;
 }
 
 

test/parallel/test-runner-reporters.js

@@ -113,7 +113,7 @@ describe('node:test reporters', { concurrency: true }, () => {
                                testFile]);
       assert.strictEqual(child.stderr.toString(), '');
       const stdout = child.stdout.toString();
-      assert.match(stdout, /{"test:enqueue":5,"test:dequeue":5,"test:complete":5,"test:start":4,"test:pass":2,"test:fail":2,"test:plan":2,"test:diagnostic":\d+}$/);
+      assert.match(stdout, /{"test:enqueue":5,"test:dequeue":5,"test:complete":5,"test:start":4,"test:pass":2,"test:fail":2,"test:plan":2,"test:summary":2,"test:diagnostic":\d+}$/);
       assert.strictEqual(stdout.slice(0, filename.length + 2), `${filename} {`);
     });
   });
@@ -125,7 +125,7 @@ describe('node:test reporters', { concurrency: true }, () => {
     assert.strictEqual(child.stderr.toString(), '');
     assert.match(
       child.stdout.toString(),
-      /^package: reporter-cjs{"test:enqueue":5,"test:dequeue":5,"test:complete":5,"test:start":4,"test:pass":2,"test:fail":2,"test:plan":2,"test:diagnostic":\d+}$/,
+      /^package: reporter-cjs{"test:enqueue":5,"test:dequeue":5,"test:complete":5,"test:start":4,"test:pass":2,"test:fail":2,"test:plan":2,"test:summary":2,"test:diagnostic":\d+}$/,
     );
   });
 
@@ -136,7 +136,7 @@ describe('node:test reporters', { concurrency: true }, () => {
     assert.strictEqual(child.stderr.toString(), '');
     assert.match(
       child.stdout.toString(),
-      /^package: reporter-esm{"test:enqueue":5,"test:dequeue":5,"test:complete":5,"test:start":4,"test:pass":2,"test:fail":2,"test:plan":2,"test:diagnostic":\d+}$/,
+      /^package: reporter-esm{"test:enqueue":5,"test:dequeue":5,"test:complete":5,"test:start":4,"test:pass":2,"test:fail":2,"test:plan":2,"test:summary":2,"test:diagnostic":\d+}$/,
     );
   });