Type "rs\n" to restart tests, fixes #871 (#3979)

* Type "rs\n" to restart tests, fixes #871

Although the `--watch` feature is somewhat controversial (see #1780), is there any reason not to make it a little easier to use in the meantime?   This adds nodemon's shortcut (`rs\n`) for manually restarting.

* fix lint errors, add unit test

* write to mochaProcess.stdin

* Trigger travis build

* add documentation

* restore trailing whitespace

* empty commit (to rerun tests)

README.md

@@ -56,7 +56,7 @@
 
 ## Sponsors
 
-Does your company use Mocha?  Ask your manager or marketing team if your company would be interested in supporting our project.  Support will allow the maintainers to dedicate more time for maintenance and new features for everyone.  Also, your company's logo will show [on GitHub](https://github.com/mochajs/mocha#readme) and on [our site](https://mochajs.org) - who doesn't want a little extra exposure?  [Here's the info](https://opencollective.com/mochajs#sponsor).
+Does your company use Mocha? Ask your manager or marketing team if your company would be interested in supporting our project. Support will allow the maintainers to dedicate more time for maintenance and new features for everyone. Also, your company's logo will show [on GitHub](https://github.com/mochajs/mocha#readme) and on [our site](https://mochajs.org) - who doesn't want a little extra exposure? [Here's the info](https://opencollective.com/mochajs#sponsor).
 
 [![MochaJS Sponsor](https://opencollective.com/mochajs/sponsor/0/avatar)](https://opencollective.com/mochajs/sponsor/0/website)
 [![MochaJS Sponsor](https://opencollective.com/mochajs/sponsor/1/avatar)](https://opencollective.com/mochajs/sponsor/1/website)
@@ -83,12 +83,12 @@ Does your company use Mocha?  Ask your manager or marketing team if your company
 
 You might want to know that:
 
-- Mocha is the *most-depended-upon* module on npm (source: [libraries.io](https://libraries.io/search?order=desc&platforms=NPM&sort=dependents_count)), and
-- Mocha is an *independent* open-source project, maintained exclusively by volunteers.
+- Mocha is the _most-depended-upon_ module on npm (source: [libraries.io](https://libraries.io/search?order=desc&platforms=NPM&sort=dependents_count)), and
+- Mocha is an _independent_ open-source project, maintained exclusively by volunteers.
 
 You might want to help:
 
-- New to contributing to Mocha?  Check out this list of [good first issues](https://github.com/mochajs/mocha/issues?q=is%3Aissue+is%3Aopen+label%3Agood-first-issue)
+- New to contributing to Mocha? Check out this list of [good first issues](https://github.com/mochajs/mocha/issues?q=is%3Aissue+is%3Aopen+label%3Agood-first-issue)
 - Mocha could use a hand with [these issues](https://github.com/mochajs/mocha/issues?q=is%3Aissue+is%3Aopen+label%3A%22help+wanted%22)
 - The [maintainer's handbook](https://github.com/mochajs/mocha/blob/master/MAINTAINERS.md) explains how things get done
 

docs/index.md

@@ -1137,6 +1137,8 @@ Rerun tests on file changes.
 
 The `--watch-files` and `--watch-ignore` options can be used to control which files are watched for changes.
 
+Tests may be rerun manually by typing ⓡ ⓢ ⏎ (same shortcut as `nodemon`).
+
 ### `--watch-files <file|directory|glob>`
 
 > _New in v7.0.0_

lib/cli/watch-run.js

@@ -63,6 +63,17 @@ module.exports = (mocha, {watchFiles, watchIgnore}, fileCollectParams) => {
     console.log('\n');
     process.exit(128 + 2);
   });
+
+  // Keyboard shortcut for restarting when "rs\n" is typed (ala Nodemon)
+  process.stdin.resume();
+  process.stdin.setEncoding('utf8');
+  process.stdin.on('data', data => {
+    const str = data
+      .toString()
+      .trim()
+      .toLowerCase();
+    if (str === 'rs') rerunner.scheduleRun();
+  });
 };
 
 /**

test/integration/options/watch.spec.js

@@ -137,6 +137,17 @@ describe('--watch', function() {
       });
     });
 
+    it('reruns when "rs\\n" typed', function() {
+      const testFile = path.join(this.tempDir, 'test.js');
+      copyFixture('__default__', testFile);
+
+      return runMochaWatch([testFile], this.tempDir, mochaProcess => {
+        mochaProcess.stdin.write('rs\n');
+      }).then(results => {
+        expect(results, 'to have length', 2);
+      });
+    });
+
     it('reruns test when file starting with . and matching --extension is changed', function() {
       const testFile = path.join(this.tempDir, 'test.js');
       copyFixture('__default__', testFile);
@@ -282,11 +293,11 @@ describe('--watch', function() {
 function runMochaWatch(args, cwd, change) {
   const [mochaProcess, resultPromise] = helpers.invokeMochaAsync(
     [...args, '--watch', '--reporter', 'json'],
-    {cwd}
+    {cwd, stdio: 'pipe'}
   );
 
   return sleep(1000)
-    .then(() => change())
+    .then(() => change(mochaProcess))
     .then(() => sleep(1000))
     .then(() => {
       mochaProcess.kill('SIGINT');