karma-ava

Run AVA tests with Karma

WARNING: Alpha level software - for evaluation use only

Install

Note: this currently requires a custom build of AVA

$ npm install --save-dev jamestalmage/ava#karma-ava karma karma-ava karma-chrome-launcher

Usage

Create a karma.conf.js, like so:

module.exports = config => {
	config.set({
		frameworks: ['ava'],
		files: [
			'test/*.js'
		],
		browsers: ['Chrome']
	});
};

Then run karma start:

$ node_modules/.bin/karma start

Notes

• Be careful not to include test helpers in the files pattern (future improvements will automatically filter helpers out).

How it works

1. The ava preprocessor (lib/preprocessor.js) bundles up a single test. Instead of returning the bundle result. It stores it at node_modules/.cache/karma-ava/<UNIQUE-HASH>.js. Karma sees a one-liner function call as the result:

   window.__AVA__.addFile(AVA_HASH, TEST_HASH, TEST_PREFIX);
   

   • AVA_HASH is the cache key for the external bundle of AVA common to all tests. It just contains AVA and its dependencies.

   • TEST_HASH is the cache key for the individual test bundle.

   • TEST_PREFIX is a string prefix to put before the test title, something like: "dirname > filename > ".

2. The ava middleware provides two routes:

   • /karma-ava/<CACHE_KEY>.js - returns the the bundle stored for that cache key (could be individual test bundles or the common AVA bundle).

   • /karma-ava/child/:avaHash/:testHash - returns an html page that simply loads two bundles (the common bundle, and the individual test bundle). These pages will be loaded into iframes by the main process.

3. lib/main.js

   • This is loaded in the main window by the framework. It provides the window.__AVA__.addFile() method discussed above, and acts as a test runner for individual iframes. It also communicates test results back to the Karma server in a format it understands.

TODO

• Create opinionated, configuration-free defaults that follow AVA's current style.
• Give the user greater control over what goes in the external/common bundle.
• Automatically ignore test helpers.
• Create a custom Karma reporter that uses AVA's own loggers.
• Honor ava config params from package.json,
• Allow for custom babel configs,
• Use watchify for faster rebuilds and smart, dependency-based rerun behavior.

License

MIT © James Talmage