introduce build/lib/electron

build/lib/electron.js

+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+'use strict';
+
+const fs = require('fs');
+const path = require('path');
+const root = path.dirname(path.dirname(__dirname));
+
+function getElectronVersion() {
+	const yarnrc = fs.readFileSync(path.join(root, '.yarnrc'), 'utf8');
+	const target = /^target "(.*)"$/m.exec(yarnrc)[1];
+
+	return target;
+}
+
+module.exports.getElectronVersion = getElectronVersion;
+
+// returns 0 if the right version of electron is in .build/electron
+if (require.main === module) {
+	const version = getElectronVersion();
+	console.log(version);
+
+	const versionFile = path.join(root, '.build', 'electron', 'version');
+	const isUpToDate = fs.existsSync(versionFile) && fs.readFileSync(versionFile, 'utf8') === `v${version}`;
+	process.exit(isUpToDate ? 0 : 1);
+}