06-configuration.md

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.js 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.*"
		],
		"helpers": [
			"**/helpers/**/*"
		],
		"sources": [
			"src/**/*"
		],
		"match": [
			"*oo",
			"!foo"
		],
		"cache": true,
		"concurrency": 5,
		"failFast": true,
		"failWithoutAssertions": false,
		"environmentVariables": {
			"MY_ENVIRONMENT_VARIABLE": "some value"
		},
		"tap": true,
		"verbose": true,
		"compileEnhancements": false,
		"require": [
			"@babel/register"
		],
		"babel": {
			"extensions": ["js", "jsx"],
			"testOptions": {
				"babelrc": false
			}
		}
	}
}

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 js extensions, even if the pattern matches other files. Specify extensions and babel.extensions to allow other file extensions
• helpers: an array of glob patterns to select helper files. Files matched here are never considered as tests. By default only selects files with js extensions, even if the pattern matches other files. Specify extensions and babel.extensions to allow other file extensions
• sources: an array of glob patterns to match files that, when changed, cause tests to be re-run (when in watch mode). 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 test and helper files under node_modules/.cache/ava. If false, files are cached in a temporary directory instead
• 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
• compileEnhancements: if false, disables power-assert — which otherwise helps provide more descriptive error messages — and detection of improper use of the t.throws() assertion
• extensions: extensions of test files that are not precompiled using AVA's Babel presets. Note that files are still compiled to enable power-assert and other features, so you may also need to set compileEnhancements to false if your files are not valid JavaScript. Setting this overrides the default "js" value, so make sure to include that extension in the list, as long as it's not included in babel.extensions
• require: extra modules to require before tests are run. Modules are required in the worker processes
• babel: test file specific Babel options. See our Babel recipe for more details
• babel.extensions: extensions of test files that will be precompiled using AVA's Babel presets. Setting this overrides the default "js" value, so make sure to include that extension in the list
• 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.

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

Using ava.config.js

To use an ava.config.js file:

1. It 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 use export default, though require() is available to load non-ES modules

The config file must have a default export, using ES modules. It can either be a plain object or a factory function which returns a plain object:

export default {
	require: ['esm']
};

export default function factory() {
	return {
		require: ['esm']
	};
};

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.

Alternative configuration files

The CLI lets you specify a specific configuration file, using the --config flag. This file is processed just like an ava.config.js file would be. When the --config flag is set, the provided file will override all configuration from the package.json and ava.config.js 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.js:

export default {
	files: ['unit-tests/**/*']
};

integration-tests.config.js:

import baseConfig from './ava.config.js';

export default {
	...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.js.

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:

import util from 'util';

import test from '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
	}
};

You can opt in to the new t.try() assertion by specifying tryAssertion:

ava.config.js:

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