test-runner: refactor to only emit test:watch:restarted event

Author: JacopoPatroclo

lib/internal/test_runner/reporter/dot.js

@@ -4,10 +4,7 @@ const {
   MathMax,
 } = primordials;
 const colors = require('internal/util/colors');
-const {
-  formatTestReport,
-  reRunTestFileMessage
-} = require('internal/test_runner/reporter/utils');
+const { formatTestReport } = require('internal/test_runner/reporter/utils');
 
 module.exports = async function* dot(source) {
   let count = 0;
@@ -28,9 +25,6 @@ module.exports = async function* dot(source) {
       columns = getLineLength();
       count = 0;
     }
-    if(type === 'test:watch:restarted'){
-      yield reRunTestFileMessage(data.file)
-    }
   }
   yield '\n';
   if (failedTests.length > 0) {

lib/internal/test_runner/reporter/spec.js

@@ -16,8 +16,7 @@ const {
   formatTestReport,
   indent,
   reporterColorMap,
-  reporterUnicodeSymbolMap,
-  reRunTestFileMessage
+  reporterUnicodeSymbolMap
 } = require('internal/test_runner/reporter/utils');
 
 class SpecReporter extends Transform {
@@ -100,8 +99,6 @@ class SpecReporter extends Transform {
       case 'test:coverage':
         return getCoverageReport(indent(data.nesting), data.summary,
                                  reporterUnicodeSymbolMap['test:coverage'], colors.blue, true);
-      case 'test:watch:restarted':
-        return reRunTestFileMessage(data.file)
       case 'test:summary':
         // We report only the root test summary
         if (data.file === undefined) {

lib/internal/test_runner/reporter/tap.js

@@ -15,7 +15,6 @@ const {
 const { inspectWithNoCustomRetry } = require('internal/errors');
 const { isError, kEmptyObject } = require('internal/util');
 const { getCoverageReport } = require('internal/test_runner/utils');
-const { reRunTestFileMessage } = require('internal/test_runner/reporter/utils');
 
 const kDefaultIndent = '    '; // 4 spaces
 const kFrameStartRegExp = /^ {4}at /;
@@ -63,9 +62,6 @@ async function * tapReporter(source) {
       case 'test:coverage':
         yield getCoverageReport(indent(data.nesting), data.summary, '# ', '', true);
         break;
-      case 'test:watch:restarted':
-        yield reRunTestFileMessage(data.file)
-        break;
     }
   }
 }

lib/internal/test_runner/reporter/utils.js

@@ -84,15 +84,10 @@ function formatTestReport(type, data, prefix = '', indent = '', hasChildren = fa
   return `${prefix}${indent}${color}${symbol}${title}${colors.white}${err}`;
 }
 
-function reRunTestFileMessage(file) {
-  return `\n[${new Date().toISOString()}] Restarting ${file}\n`
-}
-
 module.exports = {
   __proto__: null,
   reporterUnicodeSymbolMap,
   reporterColorMap,
   formatTestReport,
   indent,
-  reRunTestFileMessage
 };

lib/internal/test_runner/runner.js

@@ -480,7 +480,7 @@ function watchFiles(testFiles, opts) {
       // Reset the topLevel counter
       opts.root.harness.counters.topLevel = 0;
     }
-    opts.root.reporter[kEmitMessage]('test:watch:restarted', { file });
+
     await runningSubtests.get(file);
     runningSubtests.set(file, runTestFile(file, filesWatcher, opts));
   }
@@ -508,6 +508,8 @@ function watchFiles(testFiles, opts) {
     // Reset the root start time to recalculate the duration
     // of the run
     opts.root.clearExecutionTime();
+    opts.root.reporter[kEmitMessage]('test:watch:restarted');
+
     // Restart test files
     if (opts.isolation === 'none') {
       PromisePrototypeThen(restartTestFile(kIsolatedProcessName), undefined, (error) => {

test/parallel/test-runner-run-watch.mjs

@@ -256,6 +256,40 @@ describe('test runner watch mode', () => {
     });
     assert.notDeepStrictEqual(durations[0][1], durations[1][1]);
   });
+  
+  it('should emits test:watch:restarted when file is updated', async () => {
+    const testWatchRestarted = common.mustCall(1);
+    
+    const controller = new AbortController();
+    const stream = run({
+      cwd: tmpdir.path,
+      watch: true,
+      signal: controller.signal,
+    }).on('data', function({ type }) {
+      if (type === 'test:watch:restarted') {
+        testWatchRestarted();
+        controller.abort();
+      }
+    })
+
+    writeFileSync(join(tmpdir.path, 'test.js'), fixtureContent['test.js']);
+    
+    // eslint-disable-next-line no-unused-vars
+    for await (const _ of stream);
+  })
+  
+  it('should not emit test:watch:restarted since watch mode is disabled', async () => {
+    const stream = run({
+      cwd: tmpdir.path,
+      watch: false,
+    })
+
+    stream.on('test:watch:restarted', common.mustNotCall())
+    writeFileSync(join(tmpdir.path, 'test.js'), fixtureContent['test.js']);
+    
+    // eslint-disable-next-line no-unused-vars
+    for await (const _ of stream);
+  })
 
   describe('test runner watch mode with different cwd', () => {
     it(