AVA 4 is nearly done! We’re not expecting major breaking changes, so barring any bugs or other surprises this should be it.

As always with pre-releases though you’re best-off installing an exact version:

npm install -D -E ava@next

The cool new stuff 🆒

Worker threads 🧑‍💼

By default, test files are now run in worker threads! Huge thanks to @dnlup for landing this.

Test files should run a little quicker, since it's easier to spin up a worker thread than a child process. You can use --no-worker-threads on the command line, or workerThreads: false in your AVA configuration, to fall back to using child processes.

Shared workers are no longer experimental 🎊

Shared workers are no longer experimental. This is a powerful feature that loads a program in a worker thread in AVA's main process and then communicate with code running in the test workers. This enables your tests to better utilize shared resources during a test run, as well as providing opportunities to set up these resources before tests start (or clean them up after).

When you use watch mode, shared workers remain loaded across runs.

Improved test selection 🤳

AVA selects test files based on your package.json or ava.config.* configuration files. When used on the CLI you can then provide patterns to select a subset of these files.

You can now pass a folder and AVA will select the test files contained therein. Or you can provide a specific JavaScript file and AVA will run it even if it wasn’t selected by your configuration.

If AVA finds files based on the configuration, but none of those were selected to the CLI arguments, it now prints a warning.

Better monorepo support 🚝

AVA now looks for ava.config.* files in parent directories, until it finds a directory with a .git directory (or file). This lets you specify AVA configuration at the top of your monorepo and still run AVA from within each package.

New snapshot format 📸

@ninevra has worked tirelessly on landing a new snapshot format. It contains all information necessary to regenerate the report file. This allows for snapshots to be updated even if tests or assertions are skipped.

Previously failing test files run first 🏃

AVA now records which test files failed in the previous run. It then prioritizes testing these files when you run AVA again. Thanks @bunysae!

ESM support 🤾

AVA 4 comes with full ES module support. Both ESM and CJS entrypoints are provided so that you can use it no matter how you manage your project.

The ava.config.js file is now treated as CJS or ESM depending on module type configured in the package.json file. ava.config.mjs is now supported.

If you use JavaScript files with non-standard extensions you can configure AVA to import them.

Note that dependency tracking in watch mode does not yet work with ES modules.

Dedicated macro factory with type inference 🏭

test.macro() returns an object that can be used with
test() and hooks. The t.context type is inherited from test. When used with TypeScript this gives much better type inference.

Like with AVA 3, regular functions that also have a title property
that is a string-returning function are supported. However the type checking won’t be as good.

Source maps 🗺

AVA now uses the source map support that’s built in to Node.js itself. This should give better stack traces. However we’re not sure yet what happens if you load a program that automatically modifies stack traces.

Line number selection (where npx ava test.js:5 runs the test at line 5) now uses source maps and so should work better with TypeScript files.

Assertions as type guards 💂

Most assertions now return a boolean indicating whether they passed. If you use AVA with TypeScript, you can use this as a type guard. Thanks @jmarkham828!

(This is not supported for t.snapshot() and the "throws" assertions.)

Breaking changes 💥

AVA 4 requires at least Node.js 12.22, 14.17, 16.4 or 17. Node.js 10 is no longer supported.

If installed globally, AVA will no longer use any locally installed version. Install locally and run with npx ava instead. When running test files from another project that also has AVA installed, those test files will now fail to run (because they'll try and use that other AVA version).

Ecosystem 🏞

• Support for @ava/babel has been removed. We haven’t seen enough contributions to that package to recommend it for AVA 4. We’d be open to reinstating it in the future (just as we’d be open to support any other compilation provider).
• As a consequence, “enhanced assertions” are no longer available.
• AVA 4 requires avajs/[email protected] or newer.
• Support for the esm package has been removed.

Configuration 🗒

• ava.config.js now follows the module type configured in package.json.
• ava.config.* files may be found that are outside your project directory.

Tests and assertions 🥼

• By default test files execute in worker threads, not child processes.
• test.meta.file and test.meta.snapshotDirectory are now file URL strings.
• Whitespace in test titles is now normalized. This could result in two tests being treated as having the same title, even though they are different in code. Thanks @KillyMXI!
• test() and t.try() no longer take an array of test implementations. Use a loop instead.
• The t.throws() and t.throwAsync() assertions can no longer be called with a null value for the expectations argument.
• test.cb() and t.end() have been removed. Use async functions and util.promisify() instead.
• t.teardown() now executes in last-in-first-out order.

Snapshots 📸

• Snapshots recorded using earlier AVA versions are no longer recognized. Run npx ava -u to rebuild your snapshots after upgrading.
• Snapshots no longer recognize React elements, instead we want to provide this functionality through a plugin interface
• t.snapshot() no longer works in hooks.
• t.snapshot() no longer takes an options argument allowing you to customize the snapshot ID.

TypeScript 🪛

• The instanceOf expectation of t.throws() and t.throwsAsync() assertions must now be an Error constructor.
• You’re expected to use test.macro() when declaring macros.
• Implementation arguments now default to unknown.
• Types have been renamed. Meta replaces MetaInterface, other types with Interface suffixes now use the Fn suffix. There may be some other changes too. 4b4b2f63f184056b4038dfc692f99421038d3ec1
• t.throws() and t.throwsAsync() return undefined when the assertion fails. The type definition now matches this behavior.
• Our TypeScript definitions are now tested against TypeScript 4.4

Other changes 🤓

• We’ve removed the non-verbose reporter because it proved too hard to maintain two subtly different reporter outputs. We’d really like to rewrite the reporter.
• AVA's configuration files may now export promises or asynchronous factory methods.
• The --config argument may now point to a file that is not alongside the package.json file.
• When you use t.timeout(), AVA itself won’t time out until your test does. Thanks @OhYash!
• Multi-line snapshot labels now render correctly in Markdown. Thanks @KillyMXI!
• The reporters now clean up .test and .spec extensions from file names, as well as test- prefixes.
• Watch mode is better at detecting changes to snapshots and not rerunning tests.

New Contributors

• @Fem-Fem made their first contribution in https://github.com/avajs/ava/pull/2750
• @OhYash made their first contribution in https://github.com/avajs/ava/pull/2758
• @KillyMXI made their first contribution in https://github.com/avajs/ava/pull/2773
• @mcecode made their first contribution in https://github.com/avajs/ava/pull/2794
• @duncanfinney made their first contribution in https://github.com/avajs/ava/pull/2820
• @asaid-0 made their first contribution in https://github.com/avajs/ava/pull/2788
• @bompus made their first contribution in https://github.com/avajs/ava/pull/2843
• @StefanoA1 made their first contribution in https://github.com/avajs/ava/pull/2849
• @live627 made their first contribution in https://github.com/avajs/ava/pull/2851
• @alessandroasm made their first contribution in https://github.com/avajs/ava/pull/2863
• @eltociear made their first contribution in https://github.com/avajs/ava/pull/2870
• @hamidbae made their first contribution in https://github.com/avajs/ava/pull/2878

Full changelog since Alpha 2: https://github.com/avajs/ava/compare/v4.0.0-alpha.2...v4.0.0-rc.1

This is the second (pre)release of AVA 4 🎊 Please read the release notes for Alpha 1.

Breaking changes 💥

• Shared workers are available only in worker threads, not child processes. Thanks @dnlup! bdf2cf07
• If installed globally, AVA will no longer use any locally installed version. Install locally and run with npx ava instead 1ee1e826
• When running test files from another project that also has AVA installed, those test files will now fail to run (because they'll try and use that other AVA version) cc4e6229

Other changes 🤓

• Remove --preserve-symlink and npm link detection eef1a555
• Correctly resolve ESLint plugin helper worker path 000c42e6
• Time out ESLint config resolution after 10 seconds 3aac5e8f
• Explicit and separate CJS and ESM entrypoints 5e084445

https://github.com/avajs/ava/compare/v4.0.0-alpha.1...v4.0.0-alpha.2

This is the first (pre)release of AVA 4 🎊 There's some great new features, some cleanup of old interfaces, and some other smaller-but-still-breaking changes.

You can install the latest AVA 4 prerelease using:

npm install -D -E ava@next

The cool new stuff

Worker threads 🧑‍💼

By default, test files are now run in worker threads! Huge thanks to @dnlup for landing this. 0e5cc7dc2b1512d0abe9bfba57b26888eedea0cf

Test files should run a little quicker, since it's easier to spin up a worker thread than a child process. You can use --no-worker-threads on the command line, or workerThreads: false in your AVA configuration, to fall back to using child processes.

New snapshot format 📸

@ninevra has worked tirelessly on landing a new snapshot format. It contains all information necessary to regenerate the report file. This allows for snapshots to be updated even if tests or assertions are skipped. 14ec281dd6d71d46cf2b755e7451262dab6cbc64

Asynchronous config loading & ESM support 🤾

AVA's configuration files may now export promises or asynchronous factory methods. The ava.config.js file is now treated as CJS or ESM depending on module type configured in the package.json file. ava.config.mjs is now supported. f7cb1c7b038eba017bd77fc93d9921b1db962174 c7b782098dbaeaacfd671c12ffc5100bfb7be75d

Previously failing test files run first 🏃

AVA now records which test files failed in the previous run. It then prioritizes testing these files when you run AVA again. Thanks @bunysae! d7426720ad55ba387d86aaae3a3af06a8020c761

Assertions as type guards 💂

Most assertions now return a boolean indicating whether they passed. If you use AVA with TypeScript, you can use this as a type guard. Thanks @jmarkham828! 72a4e2fd4c931b13354ad9d10149c383b4ca48b3 5eea60836402ff0ca052cf1d017deabdf8a6fb36

(This is not supported for t.snapshot() and the "throws" assertions.)

The breaking changes 💥

• AVA 4 requires Node.js 12.20, 14.15 or 15. Node.js 10 is no longer supported 5dd22c96324f527260840e26fce8100d9a37a309
• By default test files execute in worker threads, not child processes 0e5cc7dc2b1512d0abe9bfba57b26888eedea0cf
• ava.config.js now follows the module type configured in package.json f7cb1c7b038eba017bd77fc93d9921b1db962174 c7b782098dbaeaacfd671c12ffc5100bfb7be75d
• Snapshots recorded using earlier AVA versions are no longer recognized. Run npx ava -u to rebuild your snapshots after upgrading 14ec281dd6d71d46cf2b755e7451262dab6cbc64
• Snapshots no longer recognize React elements, instead we want to provide this functionality through a plugin interface 26999c4cca86b2f50343af2cb14834144c722297
• t.snapshot() no longer works in hooks bcb750c1551cca380a0003ebc8f66987a6b16d6c
• t.snapshot() no longer takes an options argument allowing you to customize the snapshot ID d8b1e89e6e8b88e1582cf02f4cf088c87c2e058f
• test.cb() and t.end() have been removed. Use async functions and util.promisify() instead.
• The t.throws() and t.throwAsync() assertions can no longer be called with a null value for the expectations argument 7f64f5c834e8fab29f4778705ee05b2a81867879
• t.teardown() now executes in last-in-first-out order dc4483f440fe8736ff71226fd8b18c0e2cc86f51
• Support for the esm package has been removed 2011b92b638df42b4d050a19e9b37cbb19659970
• Our TypeScript definitions are now tested against TypeScript 4.2 6429581eb57232839895b6d727b32ae0dc4e12af 9cedc9770d5ac2a75c88f7f3b81c263c88989332
• A whole host of experimental features have become default, and can no longer be opted into.

Other changes 🗒

Our TypeScript recipe has been updated with ts-node and ESM instructions. Thanks @mesqueeb! a0791529c18394d92224232cf9d1696426ada505

We'd also like to thank @kiancross, @papb and @JerryGreen.

https://github.com/avajs/ava/compare/v3.15.0...v4.0.0-alpha.1

Automatic snapshot file removal

When you stop using snapshots in a test file, the next time you run ava --update-snapshots we'll remove the left-over snapshot files. Thanks @ninevra! 4f093ab

TAP improvements

@tymfear has been on a roll improving our TAP reporter. t.log() output is now compliant with the spec 99ab93a. Tests that did not run due to timeouts are now reported 98595dae58209a9062d0238c7a3dd7078a9962d1.

Next-generation configuration

AVA 4 will add full support for ESM configuration files as well as allowing you to have asynchronous factory functions a2f2614cc1e34fb9a7aa204b37b3b25559f203d9. If you're using Node.js 12 or later you can opt-in to these features in AVA 3 by enabling the nextGenConfig experiment. Say in an ava.config.mjs file:

export default {
	nonSemVerExperiments: {
		nextGenConfig: true
	},
	files: ['unit-tests/**/*]
};

This also allows you to pass an .mjs file using the --config argument.

With this experiment enabled, AVA will no longer have special treatment for ava.config.js files. Instead AVA follows Node.js' behavior, so if you've set "type": "module" you must use ESM, and otherwise you must use CommonJS.

You mustn't have an ava.config.mjs file next to an ava.config.js or ava.config.cjs file.

See https://github.com/avajs/ava/compare/v3.14.0...v3.15.0 for all changes.

Snapshot ordering

With this release, snapshot files are now ordered based on test declaration, not completion. This makes it easier to compare the human-readable reports to your test file, and also stops the .snap from changing when the reports themselves don't. You'll want to rebuild snapshots after upgrading to this release to isolate any changes. Thanks @ninevra! e66b54ce61d8bb16bbcd15b7fb90893d02e5a65c

Shared workers

We’ve been working on making AVA more extensible. One major step on this path is our new shared worker support: run code in the main process, communicate with test workers and influence execution. Find out more in our shared workers recipe.

See https://github.com/avajs/ava/compare/v3.13.0...v3.14.0 for all changes.

• t.passed can now be used in tests and teardown functions. Thanks @tymfear! 900dc6d46a1f8728dddfab1e42caef1fa8a51c85
• In AVA 4, you'll no longer be able to pass null as the expectation for t.throws() & t.throwsAsync(). You can opt in to this early by enabling the disableNullExpectations experiment. Thanks @JSimoni42! f328a6933af7aca221b08f694bb14b03701eca68
• The Enzyme recipe has been updated. Thanks @jonathansamines! db5d2c369178b78dfbd899d002a141a05655ccdc
• The TypeScript recipe has been updated. Thanks @SephReed! a3379fad3893468309a43b4b56d290f94933f082

See https://github.com/avajs/ava/compare/v3.12.1...v3.13.0 for all changes.

Configure how AVA loads test files

Normally, AVA loads all files as CommonJS, except for mjs files and if you've configured "type": "module" in your package.json.

As an experiment, you can now configure how AVA loads other file extensions. This is useful if you want to use Node.js' experimental loaders feature. Read more in our documentation. Thank you @macarie for working on this! 5c9dbb96ad0beb7521e5051390478493250ba6b0

Comparison bugfix

There was a bug in our comparison library which meant that negative-index properties on lists were not compared. This was fixed in a patch release, which will definitely be installed when you install AVA 3.12. Your tests may have been passing, even though they should have been failing. They'll fail now. Snapshots may also be different, causing tests to fail.

All changes

See https://github.com/avajs/ava/compare/v3.11.1...v3.12.1 for all changes.

Thank you @AnthumChris for making sure our ESM example used ESM syntax (20bc7810536b3b968db5461ff4093bb5ae912050).

This release fixes corrupted output of the default reporter when test or program code writes to standard out. 5ddc9fda100205a5ca315a86e27a01be443b88b1

Also, thanks to @jonathansamines we've taken another step to using AVA to test AVA. 1150991ba1921cbf888438d46350894484356078

See https://github.com/avajs/ava/compare/v3.11.0...v3.11.1 for all changes.

New t.like() assertion

Thanks to @futpib we now have a t.like() assertion 19c4f35fbae740268dedeeb4d450f813f2d5e85e:

In the following example, the map property of value must be deeply equal to that of selector. However nested.qux is ignored, because it's not in selector.

t.like({
	map: new Map([['foo', 'bar']]),
	nested: {
		baz: 'thud',
		qux: 'quux'
	}
}, {
	map: new Map([['foo', 'bar']]),
	nested: {
		baz: 'thud',
	}
})

Read more in the t.like() assertion documentation.

This assertion was previously introduced as an experiment.

VSCode 1.47 debugging improvements

You can now debug tests using the new JavaScript Debug Terminal in VSCode 1.47. We've updated our debugging recipe accordingly. Thank you @connor4312 for the documentation updates and your work on VSCode! bc39bcc3ff92cb2979564ec2e69dc72be6509f78

All changes

See https://github.com/avajs/ava/compare/v3.10.1...v3.11.0 for all changes.

It's time for another AVA release 🎉

Restricting when you can update snapshots

When executing a subset of tests, through --match or or .only() or .skip(), you can no longer also update snapshots. This prevents you from accidentally deleting snapshots. Thank you @bunysae for putting this together. f72fab40160a413f4d7ab0208979fe3e721198ea

If you are skipping a test that you can't immediately fix, but you still need to update snapshots, use .failing() instead.

Support for message strings in t.timeout() calls

Thanks to @jonathansamines you can now provide a message string when using t.timeout(). This can be useful if your test depends on some other setup that may not have been completed: ca8ea45587ebefa5584d6a7aa50adf90840701cf

test('foo', t => {
	t.timeout(100, 'make sure database has started');
	// Write your assertions here
});

t.try() does not work in hooks

t.try() has never worked in hooks, but thanks to @okyantoro it now fails properly instead of crashing. d01db61ee5e9785d9f80ad5683cac21db4b96509

t.snapshot() does not really work in hooks either

t.snapshot() sort of works in hooks, but we'll be removing this in AVA 4. You can opt in to this behavior by enabling the disableSnapshotsInHooks experiment. Again thank you @okyantoro d01db61ee5e9785d9f80ad5683cac21db4b96509.

Fixed TypeScript definition for t.like()

The experimental t.like() assertion should now work better with TypeScript.

All changes

See https://github.com/avajs/ava/compare/v3.9.0...v3.10.1 for all changes.

New experiments!

Thanks to @futpib we now have an experimental t.like() assertion 19c4f35fbae740268dedeeb4d450f813f2d5e85e:

In the following example, the map property of value must be deeply equal to that of selector. However nested.qux is ignored, because it's not in selector.

t.like({
	map: new Map([['foo', 'bar']]),
	nested: {
		baz: 'thud',
		qux: 'quux'
	}
}, {
	map: new Map([['foo', 'bar']]),
	nested: {
		baz: 'thud',
	}
})

Read more in the t.like() assertion documentation and let us know what you think.

@yjpa7145 has contributed an experiment to reverse the order in which t.teardown() functions are run, so that the last registered function is called first 952a0177758c5601a72c2b050fc0308e7fa774c7. This will be the behavior in AVA 4.

To enable both these experiments update your AVA configuration:

package.json:

{
	"ava": {
		"nonSemVerExperiments": {
			"likeAssertion": true,
			"reverseTeardowns": true
		}
	}
}

ava.config.js:

export default {
	nonSemVerExperiments: {
		likeAssertion: true,
		reverseTeardowns: true
	}
}

Reporter changes

@Michael55555 has helped us combine our reporter code into a single file b3866b6b06c98862a19f6cb27ec28b643e2f00c7. We've also made some other tweaks and improvements baaf99a792eed586678a0cf88864f3f0aa16bd7a. Let us know if anything seems amiss.

Improved diffs

@bunysae made it so that missing or extraneous objects in diffs are printed with extra depth https://github.com/concordancejs/concordance/pull/62.

Farewell Node.js 13

Node.js 13 has reached end-of-life. Per our support statement we have removed it from our test matrix and supported version list.

All changes

See https://github.com/avajs/ava/compare/v3.8.2...v3.9.0 for all changes. Thank you @paulrobertlloyd and @Autre31415 for contributing documentation improvements.

• Fix bad dependency fd92b4a3
• Use configured depth limit for diffs in assertion failures, thanks @bunysae! a5385a41

https://github.com/avajs/ava/compare/v3.8.1...v3.8.2

Node.js 14 support

Great news, this is a feature heavy release!

First off, though, AVA now officially supports Node.js 14. Thank you @zackschuster! 2e7c76b85cb65a04605fed843ee2f571afc66c37

Run tests at specific line numbers

AVA can now run tests at specific line numbers! 🎉

Given the following test file:

test.js

1: test('unicorn', t => {
2:   t.pass();
3: });
4:
5: test('rainbow', t => {
6:  t.fail();
7: });

Running npx ava test.js:2 for would run the unicorn test. In fact you could use any line number between 1 and 3.

This feature is only available from the command line. It won't work if you use tools like ts-node/register or @babel/register, and it does not currently work with @ava/babel and @ava/typescript. See https://github.com/avajs/ava/issues/2473.

Thank you @ulken for your hard work and patience to get this shipped. 1222ce9538e4890c20af695e558e3ee490f5a41b

Test-specific teardown functions

Sometimes tests have side-effects you want to clean up. @ulken has implemented t.teardown() which lets you register teardown functions within your test. They'll run once your test has finished, even if it failed: 75cbc3b2a53d3b8530266b10bed71b838bc11fec

test('read file', t => {
	fs.writeFileSync('file.txt', '👋');
	t.teardown(() => fs.unlinkSync('file.txt');

	// Run assertions
});

Node.js internal in stack traces

Thanks to @bunysae, stack traces now include Node.js internals. Previously we removed them because we wanted you to focus on your own code, but quite often they do provide context. Now they're displayed, but somewhat dimmed. 9a9351ddbee9c6c76601210c5dd8f5b0d81cc3b0

Watch mode with the default reporter

Watch mode with the default reporter once again accepts key input. Thanks @pcdevil! 59c227d9c5261117d99e8e84693b9c89c3438a92

ICYMI

• afterEach() and afterEach.always() hooks can now determine whether the test passed. Thank you @bunysae for contributing this! 8f312c0

   test('passes', t => t.pass());
   
   test.afterEach(t => {
   	if (t.passed) {
   		// Do something because the test passed
   	} else {
   		// Do something because the test failed
   	}
   });
  

• If you've ever wanted to save some files along with AVA's snapshots, you can now determine the directory path by accessing test.meta.snapshotDirectory. Thank you @ulken! cb5f9f7

All changes

See https://github.com/avajs/ava/compare/v3.7.1...v3.8.1 for all changes.

• Support parallel runs that do not need to run test files, courtesy of @micaelmbagira 26c8326b

https://github.com/avajs/ava/compare/v3.7.0...v3.7.1

If you've ever wanted to save some files along with AVA's snapshots, you can now determine the directory path by accessing test.meta.snapshotDirectory. Thank you @ulken ! cb5f9f70879ee549837c31e577e01f87970164ed

See https://github.com/avajs/ava/compare/v3.6.0...v3.7.0 for all changes.

afterEach() and afterEach.always() hooks can now determine whether the test passed. Thank you @bunysae for contributing this! 8f312c0f2c978ba39baae0f701015d79af18cbde:

test('passes', t => t.pass());

test.afterEach(t => {
	if (t.passed) {
		// Do something because the test passed
	} else {
		// Do something because the test failed
	}
});

@mbiesiad has diligently translated our documentation to Polish. Thank you @kekuu for reviewing.

Also thank you @timgates42 for fixing a typo in our documentation. ede4f322b4fa6263c8ae14ec04282ab06bb0afd4

See https://github.com/avajs/ava/compare/v3.5.0...v3.6.0 for all changes.

When using ava debug, you can now specify the address or hostname the inspector is available through by using the --host option. Thanks to @DYefimov for contributing this! 13d66519

See https://github.com/avajs/ava/compare/v3.4.0...v3.5.0 for all changes. Spoiler alert: it's just this one 😉

Introducing the t.try() assertion

The new t.try() allows you to try assertions without causing the test to fail:

test('do the thing', async t => {
  const attempt = () => t.try(async tt => {
    const result = await getResult()
    // getResult() can be flaky and sometimes throws :(
    tt.is(result, 'expected')
  })
  
  const firstAttempt = await attempt()
  if (firstAttempt.passed) return firstAttempt.commit()
  
  t.log('Retrying (just once)')
  firstAttempt.discard()
  const secondAttempt = await attempt()
  secondAttempt.commit()
})

You can use any test implementation with t.try(), including (arrays of) macros. You can decide what to do with attempts. You can even run attempts concurrently, so long as they don't use snapshot assertions.

This is great building block for handling all kinds of advanced test scenarios. We can't wait to see what you'll do with it! Find out more in the assertion documentation.

This feature was previously behind an experimental flag. That flag has now been removed. If you have enabled the flag you'll have to update your AVA config. Also note that as of this release, attempt titles are always prefixed with the title of the parent test 7ee3a0e5940a105dec447851c777ea44555e8220.

Once again, thank you @qlonik for contributing this new assertion.

In case you missed it: ESM support

As of the 3.3.0 release, AVA can load ESM test files! Check our updated ES Modules recipe for details.

Our ESM support is still incomplete. Progress is tracked in the ESM support project. Join us, won't you?

Other changes

• The t.throws() and t.throwsAsync() assertions can now be called with undefined as the second argument. Previously, if you wanted to set an assertion message but did not want to provide any expectations for the thrown error you had to pass null. That's still allowed, of course. d0e21612390d50f084f7062b051164624ef391ff @stavalfi
• ava.config.js files once again work with our @ava/typescript package f4d4edd3379e51ac733b184e20dd0228be24245a
• Our TypeScript definition no longer references @types/node 7a1dacf369a5857309effa42fc1638d7b8fe4ead
• We've improved the error message shown when test.cb() is used with asynchronous functions or observables f5a8c2b2df757886247492ce3372f1e18da36ab7 @toddkcarlson
• The Vue recipe has been updated to use jsdom-global instead of browser-env 3f9c616b44c7374404d75af63f393750160c6b84 @Scrum
• @fisker optimized how we detect ESM support 8831f54d760bbcadf8924ef6b10899a6b786c3b5

See https://github.com/avajs/ava/compare/v3.3.0...v3.4.0 for all changes.

AVA can now load ESM test files! 🎉Thank you @arlac77 for making this happen. Check our updated ES Modules recipe for details.

Our ESM support is still incomplete. Progress is tracked in the ESM support project. Join us, won't you?

Other changes

See https://github.com/avajs/ava/compare/v3.2.0...v3.3.0 for all changes.

This release improves the integration with the new @ava/typescript package, which allows AVA to load pre-compiled TypeScript files.

First, install the new @ava/typescript package:

npm install --save-dev @ava/typescript@^1.1

Now let's assume your TypeScript files are in a src directory, output to a build directory. Configure AVA like so:

ava.config.js file:

export default {
  typescript: {
    rewritePaths: {
      'src/': 'build/'
    }
  }
}

Compile your TypeScript files and run your tests! Or, to run a specific test file, run npx ava src/test.ts.

For more examples see the @ava/typescript package.

As exciting as this is, it's still early days. We need your help improving our TypeScript support. Check out the open issues.

Other changes

See https://github.com/avajs/ava/compare/v3.1.0...v3.2.0 for all changes.