Add check-version-tracker script

Author: justinfagnani

check-version-tracker.js

@@ -0,0 +1,26 @@
+/**
+ * @license
+ * Copyright (c) 2019 The Polymer Project Authors. All rights reserved.
+ * This code may only be used under the BSD style license found at
+ * http://polymer.github.io/LICENSE.txt
+ * The complete set of authors may be found at
+ * http://polymer.github.io/AUTHORS.txt
+ * The complete set of contributors may be found at
+ * http://polymer.github.io/CONTRIBUTORS.txt
+ * Code distributed by Google as part of the polymer project is also
+ * subject to an additional IP rights grant found at
+ * http://polymer.github.io/PATENTS.txt
+ */
+
+const fs = require('fs');
+const path = require('path');
+
+const version = require(path.join(__dirname, 'package.json')).version;
+const ts = fs.readFileSync(path.join(__dirname, 'src', 'lit-html.ts'));
+if (!ts.includes(version)) {
+  console.log(
+      `\nExpected lit-html.ts to contain current version "${version}"`);
+  console.log(
+      `Don't forget to update the version tracker string before release!`);
+  process.exit(1);
+}

package.json

@@ -28,6 +28,7 @@
     "quicktest": "wct -l chrome -p --npm",
     "format": "clang-format --version; find src test | grep '\\.js$\\|\\.ts$' | xargs clang-format --style=file -i",
     "lint": "tslint --project ./",
+    "prepublishOnly": "node check-version-tracker.js && npm run lint && npm test",
     "prepare": "npm run build",
     "publish-dev": "npm test && VERSION=${npm_package_version%-*}-dev.`git rev-parse --short HEAD` && npm version --no-git-tag-version $VERSION && npm publish --tag dev"
   },