8.3.1 / 2021-03-06

:bug: Fixes

• #4577: Browser: fix EvalError caused by regenerator-runtime (@snoack)
• #4574: ESM: allow import from mocha in parallel mode (@nicojs)

8.3.0 / 2021-02-11

:tada: Enhancements

• #4506: Add error code for test timeout errors (@boneskull)
• #4112: Add BigInt support to stringify util function (@JosejeSinohui)

:bug: Fixes

• #4557: Add file location when SyntaxError happens in ESM (@giltayar)
• #4521: Fix require error when bundling Mocha with Webpack (@devhazem)

:book: Documentation

• #4507: Add support for typescript-style docstrings (@boneskull)
• #4503: Add GH Actions workflow status badge (@outsideris)
• #4494: Add example of generating tests dynamically with a closure (@maxwellgerber)

:nut_and_bolt: Other

• #4556: Upgrade all dependencies to latest stable (@AviVahl)
• #4543: Update dependencies yargs and yargs-parser (@juergba)

Also thanks to @outsideris and @HyunSangHan for various fixes to our website and documentation.

8.2.1 / 2020-11-02

Fixed stuff.

:bug: Fixes

• #4489: Fix problematic handling of otherwise-unhandled Promise rejections and erroneous "done() called twice" errors (@boneskull)
• #4496: Avoid MaxListenersExceededWarning in watch mode (@boneskull)

Also thanks to @akeating for a documentation fix!

8.2.0 / 2020-10-16

The major feature added in v8.2.0 is addition of support for global fixtures.

While Mocha has always had the ability to run setup and teardown via a hook (e.g., a before() at the top level of a test file) when running tests in serial, Mocha v8.0.0 added support for parallel runs. Parallel runs are incompatible with this strategy; e.g., a top-level before() would only run for the file in which it was defined.

With global fixtures, Mocha can now perform user-defined setup and teardown regardless of mode, and these fixtures are guaranteed to run once and only once. This holds for parallel mode, serial mode, and even "watch" mode (the teardown will run once you hit Ctrl-C, just before Mocha finally exits). Tasks such as starting and stopping servers are well-suited to global fixtures, but not sharing resources--global fixtures do not share context with your test files (but they do share context with each other).

Here's a short example of usage:

// fixtures.js

// can be async or not
exports.mochaGlobalSetup = async function () {
  this.server = await startSomeServer({port: process.env.TEST_PORT});
  console.log(`server running on port ${this.server.port}`);
};

exports.mochaGlobalTeardown = async function () {
  // the context (`this`) is shared, but not with the test files
  await this.server.stop();
  console.log(`server on port ${this.server.port} stopped`);
};

// this file can contain root hook plugins as well!
// exports.mochaHooks = { ... }

Fixtures are loaded with --require, e.g., mocha --require fixtures.js.

For detailed information, please see the documentation and this handy-dandy flowchart to help understand the differences between hooks, root hook plugins, and global fixtures (and when you should use each).

:tada: Enhancements

• #4308: Support run-once global setup & teardown fixtures (@boneskull)
• #4442: Multi-part extensions (e.g., test.js) now usable with --extension option (@jordanstephens)
• #4472: Leading dots (e.g., .js, .test.js) now usable with --extension option (@boneskull)
• #4434: Output of json reporter now contains speed ("fast"/"medium"/"slow") property (@wwhurin)
• #4464: Errors thrown by serializer in parallel mode now have error codes (@evaline-ju)

For implementors of custom reporters:

• #4409: Parallel mode and custom reporter improvements (@boneskull):
  • Support custom worker-process-only reporters (Runner.prototype.workerReporter()); reporters should subclass ParallelBufferedReporter in mocha/lib/nodejs/reporters/parallel-buffered
  • Allow opt-in of object reference matching for "sufficiently advanced" custom reporters (Runner.prototype.linkPartialObjects()); use if strict object equality is needed when consuming Runner event data
  • Enable detection of parallel mode (Runner.prototype.isParallelMode())

:bug: Fixes

• #4476: Workaround for profoundly bizarre issue affecting npm v6.x causing some of Mocha's deps to be installed when mocha is present in a package's devDependencies and npm install --production is run the package's working copy (@boneskull)
• #4465: Worker processes guaranteed (as opposed to "very likely") to exit before Mocha does; fixes a problem when using nyc with Mocha in parallel mode (@boneskull)
• #4419: Restore lookupFiles() in mocha/lib/utils, which was broken/missing in Mocha v8.1.0; it now prints a deprecation warning (use const {lookupFiles} = require('mocha/lib/cli') instead) (@boneskull)

Thanks to @AviVahl, @donghoon-song, @ValeriaVG, @znarf, @sujin-park, and @majecty for other helpful contributions!

8.1.3 / 2020-08-28

:bug: Fixes

• #4425: Restore Mocha.utils.lookupFiles() and Webpack compatibility (both broken since v8.1.0); Mocha.utils.lookupFiles() is now deprecated and will be removed in the next major revision of Mocha; use require('mocha/lib/cli').lookupFiles instead (@boneskull)

8.1.2 / 2020-08-25

:bug: Fixes

• #4418: Fix command-line flag incompatibility in forthcoming Node.js v14.9.0 (@boneskull)
• #4401: Fix missing global variable in browser (@irrationnelle)

:lock: Security Fixes

• #4396: Update many dependencies (@GChuf)

:book: Documentation

• Various fixes by @sujin-park, @wwhurin & @Donghoon759

8.1.1 / 2020-08-04

:bug: Fixes

• #4394: Fix regression wherein certain reporters did not correctly detect terminal width (@boneskull)

8.1.0 / 2020-07-30

In this release, Mocha now builds its browser bundle with Rollup and Babel, which will provide the project's codebase more flexibility and consistency.

While we've been diligent about backwards compatibility, it's possible consumers of the browser bundle will encounter differences (other than an increase in the bundle size). If you do encounter an issue with the build, please report it here.

This release does not drop support for IE11.

Other community contributions came from @Devjeel, @Harsha509 and @sharath2106. Thank you to everyone who contributed to this release!

Do you read Korean? See this guide to running parallel tests in Mocha, translated by our maintainer, @outsideris.

:tada: Enhancements

• #4287: Use background colors with inline diffs for better visual distinction (@michael-brade)

:bug: Fixes

• #4328: Fix "watch" mode when Mocha run in parallel (@boneskull)
• #4382: Fix root hook execution in "watch" mode (@indieisaconcept)
• #4383: Consistent auto-generated hook titles (@cspotcode)
• #4359: Better errors when running mocha init (@boneskull)
• #4341: Fix weirdness when using delay option in browser (@craigtaub)

:lock: Security Fixes

• #4378, #4333: Update javascript-serialize (@martinoppitz, @wnghdcjfe)
• #4354: Update yargs-unparser (@martinoppitz)

:book: Documentation & Website

• #4173: Document how to use --enable-source-maps with Mocha (@bcoe)
• #4343: Clean up some API docs (@craigtaub)
• #4318: Sponsor images are now self-hosted (@Munter)

:nut_and_bolt: Other

• #4293: Use Rollup and Babel in build pipeline; add source map to published files (@Munter)

8.0.1 / 2020-06-10

The obligatory patch after a major.

:bug: Fixes

• #4328: Fix --parallel when combined with --watch (@boneskull)

8.0.0 / 2020-06-10

In this major release, Mocha adds the ability to run tests in parallel. Better late than never! Please note the breaking changes detailed below.

Let's welcome @giltayar and @nicojs to the maintenance team!

:boom: Breaking Changes

• #4164: Mocha v8.0.0 now requires Node.js v10.12.0 or newer. Mocha no longer supports the Node.js v8.x line ("Carbon"), which entered End-of-Life at the end of 2019 (@UlisesGascon)

• #4175: Having been deprecated with a warning since v7.0.0, mocha.opts is no longer supported (@juergba)

  :sparkles: WORKAROUND: Replace mocha.opts with a configuration file.

• #4260: Remove enableTimeout() (this.enableTimeout()) from the context object (@craigtaub)

  :sparkles: WORKAROUND: Replace usage of this.enableTimeout(false) in your tests with this.timeout(0).

• #4315: The spec option no longer supports a comma-delimited list of files (@juergba)

  :sparkles: WORKAROUND: Use an array instead (e.g., "spec": "foo.js,bar.js" becomes "spec": ["foo.js", "bar.js"]).

• #4309: Drop support for Node.js v13.x line, which is now End-of-Life (@juergba)

• #4282: --forbid-only will throw an error even if exclusive tests are avoided via --grep or other means (@arvidOtt)

• #4223: The context object's skip() (this.skip()) in a "before all" (before()) hook will no longer execute subsequent sibling hooks, in addition to hooks in child suites (@juergba)

• #4178: Remove previously soft-deprecated APIs (@wnghdcjfe):

  • Mocha.prototype.ignoreLeaks()
  • Mocha.prototype.useColors()
  • Mocha.prototype.useInlineDiffs()
  • Mocha.prototype.hideDiff()

:tada: Enhancements

• #4245: Add ability to run tests in parallel for Node.js (see docs) (@boneskull)

  :exclamation: See also #4244; Root Hook Plugins (docs) -- root hooks must be defined via Root Hook Plugins to work in parallel mode

• #4304: --require now works with ES modules (@JacobLey)

• #4299: In some circumstances, Mocha can run ES modules under Node.js v10 -- use at your own risk! (@giltayar)

:book: Documentation

• #4246: Add documentation for parallel mode and Root Hook plugins (@boneskull)

:nut_and_bolt: Other

• #4200: Drop mkdirp and replace it with fs.mkdirSync (@HyunSangHan)

:bug: Fixes

(All bug fixes in Mocha v8.0.0 are also breaking changes, and are listed above)