replace jest with ava

node_modules/ava/lib/fork.js

@@ -0,0 +1,117 @@
+'use strict';
+const childProcess = require('child_process');
+const path = require('path');
+const fs = require('fs');
+const Emittery = require('emittery');
+
+if (fs.realpathSync(__filename) !== __filename) {
+	console.warn('WARNING: `npm link ava` and the `--preserve-symlink` flag are incompatible. We have detected that AVA is linked via `npm link`, and that you are using either an early version of Node 6, or the `--preserve-symlink` flag. This breaks AVA. You should upgrade to Node 6.2.0+, avoid the `--preserve-symlink` flag, or avoid using `npm link ava`.');
+}
+
+// In case the test file imports a different AVA install,
+// the presence of this variable allows it to require this one instead
+const AVA_PATH = path.resolve(__dirname, '..');
+
+const workerPath = require.resolve('./worker/subprocess');
+
+module.exports = (file, options, execArgv = process.execArgv) => {
+	let finished = false;
+
+	const emitter = new Emittery();
+	const emitStateChange = evt => {
+		if (!finished) {
+			emitter.emit('stateChange', Object.assign(evt, {testFile: file}));
+		}
+	};
+
+	options = {
+		file,
+		baseDir: process.cwd(),
+		...options
+	};
+
+	const subprocess = childProcess.fork(workerPath, options.workerArgv, {
+		cwd: options.projectDir,
+		silent: true,
+		env: {NODE_ENV: 'test', ...process.env, ...options.environmentVariables, AVA_PATH},
+		execArgv
+	});
+
+	subprocess.stdout.on('data', chunk => {
+		emitStateChange({type: 'worker-stdout', chunk});
+	});
+
+	subprocess.stderr.on('data', chunk => {
+		emitStateChange({type: 'worker-stderr', chunk});
+	});
+
+	let forcedExit = false;
+	const send = evt => {
+		if (subprocess.connected && !finished && !forcedExit) {
+			subprocess.send({ava: evt}, () => {
+				// Disregard errors.
+			});
+		}
+	};
+
+	const promise = new Promise(resolve => {
+		const finish = () => {
+			finished = true;
+			resolve();
+		};
+
+		subprocess.on('message', message => {
+			if (!message.ava) {
+				return;
+			}
+
+			if (message.ava.type === 'ready-for-options') {
+				send({type: 'options', options});
+				return;
+			}
+
+			if (message.ava.type === 'ping') {
+				send({type: 'pong'});
+			} else {
+				emitStateChange(message.ava);
+			}
+		});
+
+		subprocess.on('error', err => {
+			emitStateChange({type: 'worker-failed', err});
+			finish();
+		});
+
+		subprocess.on('exit', (code, signal) => {
+			if (forcedExit) {
+				emitStateChange({type: 'worker-finished', forcedExit});
+			} else if (code > 0) {
+				emitStateChange({type: 'worker-failed', nonZeroExitCode: code});
+			} else if (code === null && signal) {
+				emitStateChange({type: 'worker-failed', signal});
+			} else {
+				emitStateChange({type: 'worker-finished', forcedExit});
+			}
+
+			finish();
+		});
+	});
+
+	return {
+		exit() {
+			forcedExit = true;
+			subprocess.kill();
+		},
+
+		notifyOfPeerFailure() {
+			send({type: 'peer-failed'});
+		},
+
+		onStateChange(listener) {
+			return emitter.on('stateChange', listener);
+		},
+
+		file,
+		promise
+	};
+};