From 2da50aa53d76cb111dbb5fe952bd0beb49f2e278 Mon Sep 17 00:00:00 2001
From: Christopher Hiller <boneskull@boneskull.com>
Date: Mon, 8 Jun 2020 15:48:40 -0700
Subject: [PATCH] add a section regarding 3p reporters & parallel mode

also rename "Migration Checklist" to "Troubleshooting Parallel Mode"
---
 docs/index.md | 310 +++++++++++++++++++++++++-------------------------
 1 file changed, 157 insertions(+), 153 deletions(-)

diff --git a/docs/index.md b/docs/index.md
index 29c02b4061..5d4cbdc87d 100644
--- a/docs/index.md
+++ b/docs/index.md
@@ -77,9 +77,9 @@ In your editor:
 
 ```js
 var assert = require('assert');
-describe('Array', function() {
-  describe('#indexOf()', function() {
-    it('should return -1 when the value is not present', function() {
+describe('Array', function () {
+  describe('#indexOf()', function () {
+    it('should return -1 when the value is not present', function () {
       assert.equal([1, 2, 3].indexOf(4), -1);
     });
   });
@@ -159,7 +159,7 @@ spawn child process
 If you use callback-based async tests, Mocha will throw an error if `done()` is called multiple times. This is handy for catching accidental double callbacks.
 
 ```javascript
-it('double done', function(done) {
+it('double done', function (done) {
   // Calling `done()` twice is an error
   setImmediate(done);
   setImmediate(done);
@@ -202,11 +202,11 @@ Mocha allows you to use any assertion library you wish. In the above example, we
 By adding an argument (usually named `done`) to `it()` to a test callback, Mocha will know that it should wait for this function to be called to complete the test. This callback accepts both an `Error` instance (or subclass thereof) _or_ a falsy value; anything else is invalid usage and throws an error (usually causing a failed test).
 
 ```js
-describe('User', function() {
-  describe('#save()', function() {
-    it('should save without error', function(done) {
+describe('User', function () {
+  describe('#save()', function () {
+    it('should save without error', function (done) {
       var user = new User('Luna');
-      user.save(function(err) {
+      user.save(function (err) {
         if (err) done(err);
         else done();
       });
@@ -218,9 +218,9 @@ describe('User', function() {
 Alternatively, use the `done()` callback directly (which will handle an error argument, if it exists):
 
 ```js
-describe('User', function() {
-  describe('#save()', function() {
-    it('should save without error', function(done) {
+describe('User', function () {
+  describe('#save()', function () {
+    it('should save without error', function (done) {
       var user = new User('Luna');
       user.save(done);
     });
@@ -233,14 +233,14 @@ describe('User', function() {
 Alternately, instead of using the `done()` callback, you may return a [Promise][mdn-promise]. This is useful if the APIs you are testing return promises instead of taking callbacks:
 
 ```js
-beforeEach(function() {
-  return db.clear().then(function() {
+beforeEach(function () {
+  return db.clear().then(function () {
     return db.save([tobi, loki, jane]);
   });
 });
 
-describe('#find()', function() {
-  it('respond with matching records', function() {
+describe('#find()', function () {
+  it('respond with matching records', function () {
     return db.find({type: 'User'}).should.eventually.have.length(3);
   });
 });
@@ -254,8 +254,8 @@ In Mocha v3.0.0 and newer, returning a `Promise` _and_ calling `done()` will res
 const assert = require('assert');
 
 // antipattern
-it('should complete this test', function(done) {
-  return new Promise(function(resolve) {
+it('should complete this test', function (done) {
+  return new Promise(function (resolve) {
     assert.ok(true);
     resolve();
   }).then(done);
@@ -269,13 +269,13 @@ The above test will fail with `Error: Resolution method is overspecified. Specif
 If your JS environment supports [async / await][mdn-async], you can also write asynchronous tests like this:
 
 ```js
-beforeEach(async function() {
+beforeEach(async function () {
   await db.clear();
   await db.save([tobi, loki, jane]);
 });
 
-describe('#find()', function() {
-  it('responds with matching records', async function() {
+describe('#find()', function () {
+  it('responds with matching records', async function () {
     const users = await db.find({type: 'User'});
     users.should.have.length(3);
   });
@@ -287,9 +287,9 @@ describe('#find()', function() {
 When testing synchronous code, omit the callback and Mocha will automatically continue on to the next test.
 
 ```js
-describe('Array', function() {
-  describe('#indexOf()', function() {
-    it('should return -1 when the value is not present', function() {
+describe('Array', function () {
+  describe('#indexOf()', function () {
+    it('should return -1 when the value is not present', function () {
       [1, 2, 3].indexOf(5).should.equal(-1);
       [1, 2, 3].indexOf(0).should.equal(-1);
     });
@@ -318,20 +318,20 @@ _If you do not need to use_ Mocha's context, lambdas should work. Be aware that
 With its default "BDD"-style interface, Mocha provides the hooks `before()`, `after()`, `beforeEach()`, and `afterEach()`. These should be used to set up preconditions and clean up after your tests.
 
 ```js
-describe('hooks', function() {
-  before(function() {
+describe('hooks', function () {
+  before(function () {
     // runs once before the first test in this block
   });
 
-  after(function() {
+  after(function () {
     // runs once after the last test in this block
   });
 
-  beforeEach(function() {
+  beforeEach(function () {
     // runs before each test in this block
   });
 
-  afterEach(function() {
+  afterEach(function () {
     // runs after each test in this block
   });
 
@@ -346,7 +346,7 @@ describe('hooks', function() {
 Any hook can be invoked with an optional description, making it easier to pinpoint errors in your tests. If a hook is given a named function, that name will be used if no description is supplied.
 
 ```js
-beforeEach(function() {
+beforeEach(function () {
   // beforeEach hook
 });
 
@@ -354,7 +354,7 @@ beforeEach(function namedFun() {
   // beforeEach:namedFun
 });
 
-beforeEach('some description', function() {
+beforeEach('some description', function () {
   // beforeEach:some description
 });
 ```
@@ -364,22 +364,22 @@ beforeEach('some description', function() {
 All hooks (`before()`, `after()`, `beforeEach()`, `afterEach()`) may be sync or async as well, behaving much like a regular test-case. For example, you may wish to populate database with dummy content before each test:
 
 ```js
-describe('Connection', function() {
+describe('Connection', function () {
   var db = new Connection(),
     tobi = new User('tobi'),
     loki = new User('loki'),
     jane = new User('jane');
 
-  beforeEach(function(done) {
-    db.clear(function(err) {
+  beforeEach(function (done) {
+    db.clear(function (err) {
       if (err) return done(err);
       db.save([tobi, loki, jane], done);
     });
   });
 
-  describe('#find()', function() {
-    it('respond with matching records', function(done) {
-      db.find({type: 'User'}, function(err, res) {
+  describe('#find()', function () {
+    it('respond with matching records', function (done) {
+      db.find({type: 'User'}, function (err, res) {
         if (err) return done(err);
         res.should.have.length(3);
         done();
@@ -393,7 +393,7 @@ describe('Connection', function() {
 
 A hook defined at the top scope of a test file (outside of a suite) is a _root hook_.
 
-As of v8.0.0, [Root Hook Plugins](#root-hook-plugins) are the preferred mechanism for setting root-level hooks.
+As of v8.0.0, [Root Hook Plugins](#root-hook-plugins) are the preferred mechanism for setting root hooks.
 
 ### Delayed Root Suite
 
@@ -402,10 +402,10 @@ As of v8.0.0, [Root Hook Plugins](#root-hook-plugins) are the preferred mechanis
 If you need to perform asynchronous operations before any of your suites are run, you may delay the root suite. Run `mocha` with the `--delay` flag. This will attach a special callback function, `run()`, to the global context:
 
 ```js
-setTimeout(function() {
+setTimeout(function () {
   // do some setup
 
-  describe('my suite', function() {
+  describe('my suite', function () {
     // ...
   });
 
@@ -418,8 +418,8 @@ setTimeout(function() {
 "Pending"--as in "someone should write these test cases eventually"--test-cases are those _without_ a callback:
 
 ```js
-describe('Array', function() {
-  describe('#indexOf()', function() {
+describe('Array', function () {
+  describe('#indexOf()', function () {
     // pending test below
     it('should return -1 when the value is not present');
   });
@@ -438,8 +438,8 @@ The exclusivity feature allows you to run _only_ the specified suite or test-cas
 by appending `.only()` to the function. Here's an example of executing only a particular suite:
 
 ```js
-describe('Array', function() {
-  describe.only('#indexOf()', function() {
+describe('Array', function () {
+  describe.only('#indexOf()', function () {
     // ...
   });
 });
@@ -450,13 +450,13 @@ _Note_: All nested suites will still be executed.
 Here's an example of executing an individual test case:
 
 ```js
-describe('Array', function() {
-  describe('#indexOf()', function() {
-    it.only('should return -1 unless present', function() {
+describe('Array', function () {
+  describe('#indexOf()', function () {
+    it.only('should return -1 unless present', function () {
       // ...
     });
 
-    it('should return the index when present', function() {
+    it('should return the index when present', function () {
       // ...
     });
   });
@@ -466,17 +466,17 @@ describe('Array', function() {
 Previous to v3.0.0, `.only()` used string matching to decide which tests to execute; this is no longer the case. In v3.0.0 or newer, `.only()` can be used multiple times to define a subset of tests to run:
 
 ```js
-describe('Array', function() {
-  describe('#indexOf()', function() {
-    it.only('should return -1 unless present', function() {
+describe('Array', function () {
+  describe('#indexOf()', function () {
+    it.only('should return -1 unless present', function () {
       // this test will be run
     });
 
-    it.only('should return the index when present', function() {
+    it.only('should return the index when present', function () {
       // this test will also be run
     });
 
-    it('should return -1 if called with a non-Array context', function() {
+    it('should return -1 if called with a non-Array context', function () {
       // this test will not be run
     });
   });
@@ -486,25 +486,25 @@ describe('Array', function() {
 You may also choose multiple suites:
 
 ```js
-describe('Array', function() {
-  describe.only('#indexOf()', function() {
-    it('should return -1 unless present', function() {
+describe('Array', function () {
+  describe.only('#indexOf()', function () {
+    it('should return -1 unless present', function () {
       // this test will be run
     });
 
-    it('should return the index when present', function() {
+    it('should return the index when present', function () {
       // this test will also be run
     });
   });
 
-  describe.only('#concat()', function() {
-    it('should return a new Array', function() {
+  describe.only('#concat()', function () {
+    it('should return a new Array', function () {
       // this test will also be run
     });
   });
 
-  describe('#slice()', function() {
-    it('should return a new Array', function() {
+  describe('#slice()', function () {
+    it('should return a new Array', function () {
       // this test will not be run
     });
   });
@@ -514,13 +514,13 @@ describe('Array', function() {
 But _tests will have precedence_:
 
 ```js
-describe('Array', function() {
-  describe.only('#indexOf()', function() {
-    it.only('should return -1 unless present', function() {
+describe('Array', function () {
+  describe.only('#indexOf()', function () {
+    it.only('should return -1 unless present', function () {
       // this test will be run
     });
 
-    it('should return the index when present', function() {
+    it('should return the index when present', function () {
       // this test will not be run
     });
   });
@@ -536,13 +536,13 @@ _Note_: Hooks, if present, will still be executed.
 This feature is the inverse of `.only()`. By appending `.skip()`, you may tell Mocha to ignore test case(s). Anything skipped will be marked as [pending](#pending-tests), and reported as such. Here's an example of skipping an individual test:
 
 ```js
-describe('Array', function() {
-  describe('#indexOf()', function() {
-    it.skip('should return -1 unless present', function() {
+describe('Array', function () {
+  describe('#indexOf()', function () {
+    it.skip('should return -1 unless present', function () {
       // this test will not be run
     });
 
-    it('should return the index when present', function() {
+    it('should return the index when present', function () {
       // this test will be run
     });
   });
@@ -552,9 +552,9 @@ describe('Array', function() {
 You can also put `.skip()` on an entire suite. This is equivalent to appending `.skip()` onto all tests in the suite. Hooks in the suite are also skipped.
 
 ```js
-describe('Array', function() {
-  describe.skip('#indexOf()', function() {
-    it('should return -1 unless present', function() {
+describe('Array', function () {
+  describe.skip('#indexOf()', function () {
+    it('should return -1 unless present', function () {
       // this test will not be run
     });
   });
@@ -612,21 +612,21 @@ before(function() {
 This will skip all `it`, `beforeEach/afterEach`, and `describe` blocks within the suite. `before/after` hooks are skipped unless they are defined at the same level as the hook containing `this.skip()`.
 
 ```js
-describe('outer', function() {
-  before(function() {
+describe('outer', function () {
+  before(function () {
     this.skip();
   });
 
-  after(function() {
+  after(function () {
     // will be executed
   });
 
-  describe('inner', function() {
-    before(function() {
+  describe('inner', function () {
+    before(function () {
       // will be skipped
     });
 
-    after(function() {
+    after(function () {
       // will be skipped
     });
   });
@@ -646,15 +646,15 @@ This feature does re-run a failed test and its corresponding `beforeEach/afterEa
 **NOTE**: Example below was written using Selenium webdriver (which [overwrites global Mocha hooks][selenium-webdriver-testing] for `Promise` chain).
 
 ```js
-describe('retries', function() {
+describe('retries', function () {
   // Retry all tests in this suite up to 4 times
   this.retries(4);
 
-  beforeEach(function() {
+  beforeEach(function () {
     browser.get('http://www.yahoo.com');
   });
 
-  it('should succeed on the 3rd try', function() {
+  it('should succeed on the 3rd try', function () {
     // Specify this test to only retry up to 2 times
     this.retries(2);
     expect($('.foo').isDisplayed()).to.eventually.be.true;
@@ -672,20 +672,20 @@ Take the following example:
 var assert = require('chai').assert;
 
 function add() {
-  return Array.prototype.slice.call(arguments).reduce(function(prev, curr) {
+  return Array.prototype.slice.call(arguments).reduce(function (prev, curr) {
     return prev + curr;
   }, 0);
 }
 
-describe('add()', function() {
+describe('add()', function () {
   var tests = [
     {args: [1, 2], expected: 3},
     {args: [1, 2, 3], expected: 6},
-    {args: [1, 2, 3, 4], expected: 10}
+    {args: [1, 2, 3, 4], expected: 10},
   ];
 
-  tests.forEach(function(test) {
-    it('correctly adds ' + test.args.length + ' args', function() {
+  tests.forEach(function (test) {
+    it('correctly adds ' + test.args.length + ' args', function () {
       var res = add.apply(null, test.args);
       assert.equal(res, test.expected);
     });
@@ -721,10 +721,10 @@ There are three levels of test duration (depicted in the following image):
 To tweak what's considered "slow", you can use the `slow()` method:
 
 ```js
-describe('something slow', function() {
+describe('something slow', function () {
   this.slow(300000); // five minutes
 
-  it('should take long enough for me to go make a sandwich', function() {
+  it('should take long enough for me to go make a sandwich', function () {
     // ...
   });
 });
@@ -737,14 +737,14 @@ describe('something slow', function() {
 Suite-level timeouts may be applied to entire test "suites", or disabled via `this.timeout(0)`. This will be inherited by all nested suites and test-cases that do not override the value.
 
 ```js
-describe('a suite of tests', function() {
+describe('a suite of tests', function () {
   this.timeout(500);
 
-  it('should take less than 500ms', function(done) {
+  it('should take less than 500ms', function (done) {
     setTimeout(done, 300);
   });
 
-  it('should take less than 500ms as well', function(done) {
+  it('should take less than 500ms as well', function (done) {
     setTimeout(done, 250);
   });
 });
@@ -755,7 +755,7 @@ describe('a suite of tests', function() {
 Test-specific timeouts may also be applied, or the use of `this.timeout(0)` to disable timeouts all together:
 
 ```js
-it('should take less than 500ms', function(done) {
+it('should take less than 500ms', function (done) {
   this.timeout(500);
   setTimeout(done, 300);
 });
@@ -766,8 +766,8 @@ it('should take less than 500ms', function(done) {
 Hook-level timeouts may also be applied:
 
 ```js
-describe('a suite of tests', function() {
-  beforeEach(function(done) {
+describe('a suite of tests', function () {
+  beforeEach(function (done) {
     this.timeout(3000); // A very long environment setup.
     setTimeout(done, 2500);
   });
@@ -1065,17 +1065,17 @@ Cause Mocha to only run tests matching the given `regexp`, which is internally c
 Suppose, for example, you have "api" related tests, as well as "app" related tests, as shown in the following snippet; One could use `--grep api` or `--grep app` to run one or the other. The same goes for any other part of a suite or test-case title, `--grep users` would be valid as well, or even `--grep GET`.
 
 ```js
-describe('api', function() {
-  describe('GET /api/users', function() {
-    it('respond with an array of users', function() {
+describe('api', function () {
+  describe('GET /api/users', function () {
+    it('respond with an array of users', function () {
       // ...
     });
   });
 });
 
-describe('app', function() {
-  describe('GET /users', function() {
-    it('respond with an array of users', function() {
+describe('app', function () {
+  describe('GET /users', function () {
+    it('respond with an array of users', function () {
       // ...
     });
   });
@@ -1215,12 +1215,12 @@ A _root hook_ is a hook in a test file which is _not defined_ within a suite. An
 // test/setup.js
 
 // root hook to run before every test (even in other files)
-beforeEach(function() {
+beforeEach(function () {
   doMySetup();
 });
 
 // root hook to run after every test (even in other files)
-afterEach(function() {
+afterEach(function () {
   doMyTeardown();
 });
 ```
@@ -1246,15 +1246,19 @@ Here are a couple suggested workarounds:
 
 Parallel mode is only available in Node.js, for now.
 
-### Migration Checklist
+### Limited Reporter API for Third-Party Reporters
+
+Third-party reporters may encounter issues when attempting to access non-existent properties within `Test`, `Suite`, and `Hook` objects. If a third-party reporter does not work in parallel mode (but otherwise works in serial mode), please [file an issue](https://github.com/mochajs/mocha/issues/new).
+
+### Troubleshooting Parallel Mode
 
 If you find your tests don't work properly when run with [`--parallel`](#-parallel-p), either shrug and move on, or use this handy-dandy checklist to get things working:
 
 - :white_check_mark: Ensure you are using a [supported reporter](#reporter-limitations).
 - :white_check_mark: Ensure you are not using [other unsupported flags](#file-order-is-non-deterministic).
 - :white_check_mark: Double-check your [config file](#configuring-mocha-nodejs); options set in config files will be merged with any command-line option.
-- :white_check_mark: Look for root-level hooks (they look like [this](#root-hooks-are-not-global)) in your tests. Move them into a [root-level hook plugin](#root-hook-plugins).
-- :white_check_mark: Do any assertion, mock, or other test libraries you're consuming use root-level hooks? They may need to be [migrated](#migrating-a-library-to-use-root-hook-plugins) for compatibility with parallel mode.
+- :white_check_mark: Look for root hooks (they look like [this](#root-hooks-are-not-global)) in your tests. Move them into a [Root Hook Plugin](#root-hook-plugins).
+- :white_check_mark: Do any assertion, mock, or other test libraries you're consuming use root hooks? They may need to be [migrated](#migrating-a-library-to-use-root-hook-plugins) for compatibility with parallel mode.
 - :white_check_mark: If tests are unexpectedly timing out, you may need to increase the default test timeout (via [`--timeout`](#-timeout-ms-t-ms))
 - :white_check_mark: Ensure your tests do not depend on being run in a specific order.
 - :white_check_mark: Ensure your tests clean up after themselves; remove temp files, handles, sockets, etc. Don't try to share state or resources between test files.
@@ -1290,7 +1294,7 @@ exports.mochaHooks = {
   beforeEach(done) {
     // do something before every test
     done();
-  }
+  },
 };
 ```
 
@@ -1307,7 +1311,7 @@ export const mochaHooks = {
   beforeEach(done) {
     // do something before every test
     done();
-  }
+  },
 };
 ```
 
@@ -1343,7 +1347,7 @@ export const mochaHooks = {
     if (require('os').userInfo().username === 'bob') {
       return this.skip();
     }
-  }
+  },
 };
 ```
 
@@ -1356,14 +1360,14 @@ Multiple root hooks can be defined in a single plugin, for organizational purpos
 
 export const mochaHooks = {
   beforeEach: [
-    function(done) {
+    function (done) {
       // do something before every test,
       // then run the next hook in this array
     },
-    async function() {
+    async function () {
       // async or Promise-returning functions allowed
-    }
-  ]
+    },
+  ],
 };
 ```
 
@@ -1379,20 +1383,20 @@ export const mochaHooks = () => {
     // root hooks object
     return {
       beforeEach: [
-        function() {
+        function () {
           // CI-specific beforeEach
         },
-        function() {
+        function () {
           // some other CI-specific beforeEach
-        }
-      ]
+        },
+      ],
     };
   }
   // root hooks object
   return {
     beforeEach() {
       // regular beforeEach
-    }
+    },
   };
 };
 ```
@@ -1410,7 +1414,7 @@ export const mochaHooks = async () => {
     return {
       beforeEach() {
         // something
-      }
+      },
     };
   }
 };
@@ -1435,16 +1439,16 @@ For example, given the following file, `test/test.spec.js`, containing root hook
 ```js
 // test/test.spec.js
 
-beforeEach(function() {
+beforeEach(function () {
   // global setup for all tests
 });
 
-after(function() {
+after(function () {
   // one-time final cleanup
 });
 
-describe('my test suite', function() {
-  it('should have run my global setup', function() {
+describe('my test suite', function () {
+  it('should have run my global setup', function () {
     // make assertion
   });
 });
@@ -1472,8 +1476,8 @@ Your original `test/test.spec.js` should now contain:
 ```js
 // test/test.spec.js
 
-describe('my test suite', function() {
-  it('should have run my global setup', function() {
+describe('my test suite', function () {
+  it('should have run my global setup', function () {
     // make assertion
   });
 });
@@ -1502,24 +1506,24 @@ The **BDD** interface provides `describe()`, `context()`, `it()`, `specify()`, `
 > All of the previous examples were written using the **BDD** interface.
 
 ```js
-describe('Array', function() {
-  before(function() {
+describe('Array', function () {
+  before(function () {
     // ...
   });
 
-  describe('#indexOf()', function() {
-    context('when not present', function() {
-      it('should not throw an error', function() {
-        (function() {
+  describe('#indexOf()', function () {
+    context('when not present', function () {
+      it('should not throw an error', function () {
+        (function () {
           [1, 2, 3].indexOf(4);
         }.should.not.throw());
       });
-      it('should return -1', function() {
+      it('should return -1', function () {
         [1, 2, 3].indexOf(4).should.equal(-1);
       });
     });
-    context('when present', function() {
-      it('should return the index where the element first appears in the array', function() {
+    context('when present', function () {
+      it('should return the index where the element first appears in the array', function () {
         [1, 2, 3].indexOf(3).should.equal(2);
       });
     });
@@ -1532,13 +1536,13 @@ describe('Array', function() {
 The **TDD** interface provides `suite()`, `test()`, `suiteSetup()`, `suiteTeardown()`, `setup()`, and `teardown()`:
 
 ```js
-suite('Array', function() {
-  setup(function() {
+suite('Array', function () {
+  setup(function () {
     // ...
   });
 
-  suite('#indexOf()', function() {
-    test('should return -1 when not present', function() {
+  suite('#indexOf()', function () {
+    test('should return -1 when not present', function () {
       assert.equal(-1, [1, 2, 3].indexOf(4));
     });
   });
@@ -1551,17 +1555,17 @@ The **Exports** interface is much like Mocha's predecessor [expresso][]. The key
 
 ```js
 module.exports = {
-  before: function() {
+  before: function () {
     // ...
   },
 
   Array: {
     '#indexOf()': {
-      'should return -1 when not present': function() {
+      'should return -1 when not present': function () {
         [1, 2, 3].indexOf(4).should.equal(-1);
-      }
-    }
-  }
+      },
+    },
+  },
 };
 ```
 
@@ -1576,12 +1580,12 @@ function ok(expr, msg) {
 
 suite('Array');
 
-test('#length', function() {
+test('#length', function () {
   var arr = [1, 2, 3];
   ok(arr.length == 3);
 });
 
-test('#indexOf()', function() {
+test('#indexOf()', function () {
   var arr = [1, 2, 3];
   ok(arr.indexOf(1) == 0);
   ok(arr.indexOf(2) == 1);
@@ -1590,7 +1594,7 @@ test('#indexOf()', function() {
 
 suite('String');
 
-test('#length', function() {
+test('#length', function () {
   ok('foo'.length == 3);
 });
 ```
@@ -1607,13 +1611,13 @@ var pre = require('mocha').before;
 var assertions = require('mocha').it;
 var assert = require('chai').assert;
 
-testCase('Array', function() {
-  pre(function() {
+testCase('Array', function () {
+  pre(function () {
     // ...
   });
 
-  testCase('#indexOf()', function() {
-    assertions('should return -1 when not present', function() {
+  testCase('#indexOf()', function () {
+    assertions('should return -1 when not present', function () {
       assert.equal([1, 2, 3].indexOf(4), -1);
     });
   });
@@ -1717,9 +1721,9 @@ The Doc reporter outputs a hierarchical HTML body representation of your tests.
 For example, suppose you have the following JavaScript:
 
 ```js
-describe('Array', function() {
-  describe('#indexOf()', function() {
-    it('should return -1 when the value is not present', function() {
+describe('Array', function () {
+  describe('#indexOf()', function () {
+    it('should return -1 when the value is not present', function () {
       [1, 2, 3].indexOf(5).should.equal(-1);
       [1, 2, 3].indexOf(0).should.equal(-1);
     });
@@ -1875,7 +1879,7 @@ mocha.setup('tdd');
 
 // This is equivalent to the above.
 mocha.setup({
-  ui: 'tdd'
+  ui: 'tdd',
 });
 
 // Examples of options:
@@ -1890,7 +1894,7 @@ mocha.setup({
   retries: 3,
   slow: '100',
   timeout: '2000',
-  ui: 'bdd'
+  ui: 'bdd',
 });
 ```