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06-configuration.md

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Configuration

Translations: Français

All of the CLI options can be configured in the ava section of either your package.json file, or an ava.config.* file. This allows you to modify the default behavior of the ava command, so you don't have to repeatedly type the same options on the command prompt.

To ignore files, prefix the pattern with an ! (exclamation mark).

package.json:

{
	"ava": {
		"files": [
			"test/**/*",
			"!test/exclude-files-in-this-directory",
			"!**/exclude-files-with-this-name.*"
		],
		"match": [
			"*oo",
			"!foo"
		],
		"concurrency": 5,
		"failFast": true,
		"failWithoutAssertions": false,
		"environmentVariables": {
			"MY_ENVIRONMENT_VARIABLE": "some value"
		},
		"verbose": true,
		"require": [
			"./my-helper-module.js"
		],
		"nodeArguments": [
			"--trace-deprecation",
			"--napi-modules"
		]
	}
}

Arguments passed to the CLI will always take precedence over the CLI options configured in package.json.

Options

  • files: an array of glob patterns to select test files. Files with an underscore prefix are ignored. By default only selects files with cjs, mjs & js extensions, even if the pattern matches other files. Specify extensions to allow other file extensions
  • ignoredByWatcher: an array of glob patterns to match files that, even if changed, are ignored by the watcher. See the watch mode recipe for details
  • match: not typically useful in the package.json configuration, but equivalent to specifying --match on the CLI
  • cache: cache compiled files under node_modules/.cache/ava. If false, files are cached in a temporary directory instead
  • concurrency: max number of test files running at the same time (default: CPU cores)
  • workerThreads: use worker threads to run tests (requires AVA 4, enabled by default). If false, tests will run in child processes (how AVA 3 behaves)
  • failFast: stop running further tests once a test fails
  • failWithoutAssertions: if false, does not fail a test if it doesn't run assertions
  • environmentVariables: specifies environment variables to be made available to the tests. The environment variables defined here override the ones from process.env
  • tap: if true, enables the TAP reporter
  • verbose: if true, enables verbose output
  • snapshotDir: specifies a fixed location for storing snapshot files. Use this if your snapshots are ending up in the wrong location
  • extensions: extensions of test files. Setting this overrides the default ["cjs", "mjs", "js"] value, so make sure to include those extensions in the list. Experimentally you can configure how files are loaded
  • require: extra modules to require before tests are run. Modules are required in the worker processes
  • timeout: Timeouts in AVA behave differently than in other test frameworks. AVA resets a timer after each test, forcing tests to quit if no new test results were received within the specified timeout. This can be used to handle stalled tests. See our timeout documentation for more options.
  • nodeArguments: Configure Node.js arguments used to launch worker processes.

Note that providing files on the CLI overrides the files option.

Provide the babel option (and install @ava/babel as an additional dependency) to enable Babel compilation.

Provide the typescript option (and install @ava/typescript as an additional dependency) to enable (rudimentary) TypeScript support.

Using ava.config.* files

Rather than specifying the configuration in the package.json file you can use ava.config.js or ava.config.cjs files.

To use these files:

  1. They must be in the same directory as your package.json
  2. Your package.json must not contain an ava property (or, if it does, it must be an empty object)
  3. You must not both have an ava.config.js and an ava.config.cjs file

AVA 3 recognizes ava.config.mjs files but refuses to load them. This is changing in AVA 4, see below.

ava.config.js

In AVA 3, for ava.config.js files you must use export default. You cannot use "module scope". You cannot import dependencies.

This is changing in AVA 4, see below.

The default export can either be a plain object or a factory function which returns a plain object:

export default {
	require: ['./_my-test-helper']
};
export default function factory() {
	return {
		require: ['./_my-test-helper']
	};
};

The factory function is called with an object containing a projectDir property, which you could use to change the returned configuration:

export default ({projectDir}) => {
	if (projectDir === '/Users/username/projects/my-project') {
		return {
			// Config A
		};
	}

	return {
		// Config B
	};
};

Note that the final configuration must not be a promise. This is changing in AVA 4, see below.

ava.config.cjs

For ava.config.cjs files you must assign module.exports. "Module scope" is available. You can require() dependencies.

The module export can either be a plain object or a factory function which returns a plain object:

module.exports = {
	require: ['./_my-test-helper']
};
module.exports = () => {
	return {
		require: ['./_my-test-helper']
	};
};

The factory function is called with an object containing a projectDir property, which you could use to change the returned configuration:

module.exports = ({projectDir}) => {
	if (projectDir === '/Users/username/projects/my-project') {
		return {
			// Config A
		};
	}

	return {
		// Config B
	};
};

Note that the final configuration must not be a promise. This is changing in AVA 4, see below.

Alternative configuration files

The CLI lets you specify a specific configuration file, using the --config flag. This file must have either a .js or .cjs extension and is processed like an ava.config.js or ava.config.cjs file would be.

AVA 4 also supports .mjs extensions, see below.

When the --config flag is set, the provided file will override all configuration from the package.json and ava.config.js or ava.config.cjs files. The configuration is not merged.

The configuration file must be in the same directory as the package.json file.

You can use this to customize configuration for a specific test run. For instance, you may want to run unit tests separately from integration tests:

ava.config.cjs:

module.exports = {
	files: ['unit-tests/**/*']
};

integration-tests.config.cjs:

const baseConfig = require('./ava.config.cjs');

module.exports = {
	...baseConfig,
	files: ['integration-tests/**/*']
};

You can now run your unit tests through npx ava and the integration tests through npx ava --config integration-tests.config.cjs.

Next generation configuration

AVA 4 will add full support for ESM configuration files as well as allowing you to have asynchronous factory functions. 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.

Object printing depth

By default, AVA prints nested objects to a depth of 3. However, when debugging tests with deeply nested objects, it can be useful to print with more detail. This can be done by setting util.inspect.defaultOptions.depth to the desired depth, before the test is executed:

const util = require('util');

const test = require('ava');

util.inspect.defaultOptions.depth = 5;  // Increase AVA's printing depth

test('My test', t => {
	t.deepEqual(someDeeplyNestedObject, theExpectedValue);
});

AVA has a minimum depth of 3.

Experiments

From time to time, AVA will implement experimental features. These may change or be removed at any time, not just when there's a new major version. You can opt in to such a feature by enabling it in the nonSemVerExperiments configuration.

ava.config.js:

export default {
	nonSemVerExperiments: {
		feature: true
	}
};

Configuring module formats

Node.js can only load non-standard extension as ES Modules when using experimental loaders. To use this you'll also have to configure AVA to import() your test file.

This is an experimental feature in AVA 3. You can opt in to it by enabling the configurableModuleFormat experiment. Afterwards, you'll be able to specify per-extension module formats using an object form.

This feature is available by default in AVA 4.

As with the array form, you need to explicitly list js, cjs, and mjs extensions. These must be set using the true value; other extensions are configurable using either 'commonjs' or 'module':

ava.config.js:

export default {
	nonSemVerExperiments: {
		configurableModuleFormat: true
	},
	extensions: {
		js: true,
		ts: 'module'
	}
};

Node arguments

The nodeArguments configuration may be used to specify additional arguments for launching worker processes. These are combined with --node-arguments passed on the CLI and any arguments passed to the node binary when starting AVA.