fix: begin running tests immediately instead of waiting for watcher

Author: jedwards1211

lib/cli/watch-run.js

@@ -9,6 +9,7 @@ const isPathInside = require('is-path-inside');
 const {minimatch} = require('minimatch');
 const Context = require('../context');
 const collectFiles = require('./collect-files');
+const fs = require('node:fs');
 
 /**
  * @typedef {import('chokidar').FSWatcher} FSWatcher
@@ -385,6 +386,10 @@ function createPathMatcher(allowed, ignored, basePath) {
   return matcher;
 }
 
+// grab Date.now before anything like sinon.createFakeTimers can monkeypatch it
+// eslint-disable-next-line no-restricted-globals
+const dateNow = Date.now;
+
 /**
  * Bootstraps a Chokidar watcher. Handles keyboard input & signals
  * @param {Mocha} mocha - Mocha instance
@@ -434,26 +439,41 @@ const createWatcher = (
     ignored: matcher.ignore
   });
 
-  const rerunner = createRerunner(mocha, watcher, {
+  const rerunner = createRerunner(mocha, watcher, matcher, {
     beforeRun
   });
 
-  watcher.on('ready', async () => {
+  const startTime = dateNow();
+  let ready = false;
+  watcher.on('ready', () => {
     debug('watcher ready');
-    if (!globalFixtureContext) {
-      debug('triggering global setup');
-      globalFixtureContext = await mocha.runGlobalSetup();
-    }
-    rerunner.run();
+    ready = true;
   });
 
-  watcher.on('all', (_event, filePath) => {
-    // only allow file paths that match the allowed patterns
-    if (matcher.allow(filePath)) {
-      rerunner.scheduleRun();
+  watcher.on('all', async function handleEvent(event, filePath, stat) {
+    if (exiting || !matcher.allow(filePath)) return;
+    if (event === 'unlink' || (stat ? stat.mtime > startTime : ready)) {
+      // we don't want to accidentally trigger a run before globalFixtureContext
+      // has been created.  If it hasn't then it's okay to do nothing here because
+      // the code that creates globalFixtureContext will run the tests afterward
+      if (globalFixtureContext) {
+        rerunner.scheduleRun();
+      }
+      return;
+    }
+    if (!ready && !stat) {
+      fs.stat(filePath, (err, stat) => {
+        if (stat) handleEvent(event, filePath, stat);
+      });
     }
   });
 
+  debug('triggering global setup');
+  mocha.runGlobalSetup().then(context => {
+    globalFixtureContext = context;
+    rerunner.run();
+  });
+
   hideCursor();
   process.on('exit', () => {
     showCursor();
@@ -509,13 +529,14 @@ const createWatcher = (
  *
  * @param {Mocha} mocha - Mocha instance
  * @param {FSWatcher} watcher - Chokidar `FSWatcher` instance
+ * @param {PathMatcher} matcher - `PathMatcher` instance
  * @param {Object} [opts] - Options!
  * @param {BeforeWatchRun} [opts.beforeRun] - Function to call before `mocha.run()`
  * @returns {Rerunner}
  * @ignore
  * @private
  */
-const createRerunner = (mocha, watcher, {beforeRun} = {}) => {
+const createRerunner = (mocha, watcher, matcher, {beforeRun} = {}) => {
   // Set to a `Runner` when mocha is running. Set to `null` when mocha is not
   // running.
   let runner = null;
@@ -529,7 +550,7 @@ const createRerunner = (mocha, watcher, {beforeRun} = {}) => {
       runner = mocha.run(() => {
         debug('finished watch run');
         runner = null;
-        blastCache(watcher);
+        blastCache(matcher);
         if (rerunScheduled) {
           rerun();
         } else {
@@ -566,25 +587,6 @@ const createRerunner = (mocha, watcher, {beforeRun} = {}) => {
   };
 };
 
-/**
- * Return the list of absolute paths watched by a Chokidar watcher.
- *
- * @param watcher - Instance of a Chokidar watcher
- * @return {string[]} - List of absolute paths
- * @ignore
- * @private
- */
-const getWatchedFiles = watcher => {
-  const watchedDirs = watcher.getWatched();
-  return Object.keys(watchedDirs).reduce(
-    (acc, dir) => [
-      ...acc,
-      ...watchedDirs[dir].map(file => path.join(dir, file))
-    ],
-    []
-  );
-};
-
 /**
  * Hide the cursor.
  * @ignore
@@ -613,14 +615,17 @@ const eraseLine = () => {
 
 /**
  * Blast all of the watched files out of `require.cache`
- * @param {FSWatcher} watcher - Chokidar FSWatcher
+ * @param {PathMatcher} matcher - `PathMatcher` instance
  * @ignore
  * @private
  */
-const blastCache = watcher => {
-  const files = getWatchedFiles(watcher);
-  files.forEach(file => {
-    delete require.cache[file];
-  });
-  debug('deleted %d file(s) from the require cache', files.length);
+const blastCache = matcher => {
+  let deletedCount = 0;
+  for (const key in require.cache) {
+    if (matcher.allow(key)) {
+      deletedCount++;
+      delete require.cache[key];
+    }
+  }
+  debug('deleted %d file(s) from the require cache', deletedCount);
 };

test/integration/helpers.js

@@ -492,8 +492,6 @@ async function runMochaWatchJSONAsync(args, opts, change) {
   );
 }
 
-const touchRef = new Date();
-
 /**
  * Synchronously touch a file. Creates
  * the file and all its parent directories if necessary.
@@ -503,6 +501,7 @@ const touchRef = new Date();
 function touchFile(filepath) {
   fs.mkdirSync(path.dirname(filepath), { recursive: true });
   try {
+    const touchRef = new Date();
     fs.utimesSync(filepath, touchRef, touchRef);
   } catch (err) {
     const fd = fs.openSync(filepath, 'a');