[1] Add --watchAll option and run tests immediately on start up (#1475)

* Replace --watch=all option with --watchAll

* Run tests immediately on start up when using --watch or --watchAll

packages/jest-cli/src/SearchSource.js

@@ -208,7 +208,7 @@ class SearchSource {
   ): string {
     if (patternInfo.onlyChanged) {
       const guide = patternInfo.watch
-        ? 'starting Jest with `jest --watch=all`'
+        ? 'starting Jest with `jest --watchAll`'
         : 'running Jest without `-o`';
       return 'No tests found related to changed and uncommitted files.\n' +
         'Note: If you are using dynamic `require`-calls or no tests related ' +

packages/jest-cli/src/cli/args.js

@@ -28,9 +28,11 @@ const check = (argv: Object) => {
     );
   }
 
-  if (argv.watchExtensions && argv.watch === undefined) {
+  if (argv.onlyChanged && argv.watchAll) {
     throw new Error(
-      '--watchExtensions can only be specified together with --watch.',
+      'Both --onlyChanged and --watchAll were specified, but these two ' +
+      'options do not make sense together. Try the --watch option which ' +
+      'reruns only tests related to changed files.',
     );
   }
 
@@ -148,10 +150,18 @@ const options = {
   watch: {
     description: wrap(
       'Watch files for changes and rerun tests related to changed files. ' +
-      'If you want to re-run all tests when a file has changed, you can ' +
-      'call Jest using `--watch=all`.',
+      'If you want to re-run all tests when a file has changed, use the ' +
+      '`--watchAll` option.',
     ),
-    type: 'string',
+    type: 'boolean',
+  },
+  watchAll: {
+    description: wrap(
+      'Watch files for changes and rerun all tests. If you want to re-run ' +
+       'only the tests related to the changed files, use the ' +
+      '`--watch` option.',
+    ),
+    type: 'boolean',
   },
   bail: {
     alias: 'b',

packages/jest-cli/src/jest.js

@@ -51,7 +51,7 @@ function buildTestPathPatternInfo(argv) {
     return {
       lastCommit: argv.lastCommit,
       onlyChanged: true,
-      watch: argv.watch !== undefined,
+      watch: argv.watch,
     };
   }
   if (argv.testPathPattern) {
@@ -151,17 +151,25 @@ function runCLI(argv: Object, root: Path, onComplete: () => void) {
         pipe.write('test framework = ' + testFramework.name + '\n');
         pipe.write('config = ' + JSON.stringify(config, null, '  ') + '\n');
       }
-      if (argv.watch !== undefined) {
-        if (argv.watch !== 'all') {
-          argv.onlyChanged = true;
-        }
+      if (argv.watch || argv.watchAll) {
+        argv.onlyChanged = !argv.watchAll;
 
         return new Promise(resolve => {
           getWatcher(config, root, watcher => {
             let timer;
             let isRunning;
+            const startRun = () => {
+              isRunning = true;
+              runJest(config, argv, pipe, () => isRunning = false)
+                .then(
+                  resolve,
+                  error => console.error(chalk.red(error)),
+                );
+            };
 
             pipe.write(CLEAR);
+            startRun();
+
             watcher.on('all', (_, filePath) => {
               pipe.write(CLEAR);
               filePath = path.join(root, filePath);
@@ -172,17 +180,7 @@ function runCLI(argv: Object, root: Path, onComplete: () => void) {
                   clearTimeout(timer);
                   timer = null;
                 }
-                timer = setTimeout(
-                  () => {
-                    isRunning = true;
-                    runJest(config, argv, pipe, () => isRunning = false)
-                      .then(
-                        resolve,
-                        error => console.error(chalk.red(error)),
-                      );
-                  },
-                  WATCHER_DEBOUNCE,
-                );
+                timer = setTimeout(startRun, WATCHER_DEBOUNCE);
               }
             });
           });