Automated Chromedriver updates (#230)

Add an npm script `update-chromedriver` to automate Chromedriver updates

Author: js-kyle

.npmignore

@@ -5,6 +5,7 @@ tmp
 Dockerfile
 test-driver.sh
 testInstall.js
+update.js
 *.tgz
 .vscode
 .editorconfig

README.md

@@ -210,7 +210,7 @@ executed as a callback at the end of your tests
 The NPM package version tracks the version of chromedriver that will be installed,
 with an additional build number that is used for revisions to the installer.
 You can use the package version number to install a specific version, or use the
-setting to a specific version. To always install the latest version of Chromedriver,
+setting to a specific version. If there is a new Chromedriver version available which is not yet available as a version of `node-chromedriver`, the npm command `npm run update-chromedriver` in this repository can be used to make the required updates to this module, please submit the change as a PR. To always install the latest version of Chromedriver,
 use `LATEST` as the version number:
 
 ```shell

package.json

@@ -22,7 +22,8 @@
     "chromedriver": "./bin/chromedriver"
   },
   "scripts": {
-    "install": "node install.js"
+    "install": "node install.js",
+    "update-chromedriver": "node update.js"
   },
   "dependencies": {
     "del": "^4.1.1",

update.js

@@ -0,0 +1,39 @@
+const request = require('request');
+const fs = require('fs');
+const execSync = require('child_process').execSync;
+const CURRENT_VERSION = require('./lib/chromedriver').version;
+
+// fetch the latest chromedriver version
+const getLatest = (cb) => {
+  request('https://chromedriver.storage.googleapis.com/LATEST_RELEASE', (err, response, body) => {
+    if (err) {
+      process.exit(1);
+    }
+    return cb(body);
+  });
+};
+
+/* Provided a new Chromedriver version such as 77.0.3865.40:
+   - update the version inside the ./lib/chromedriver helper file e.g. exports.version = '77.0.3865.40';
+   - bumps package.json version number
+   - add a git tag using the new node-chromedriver version
+   - add a git commit, e.g. Bump version to 77.0.0
+*/
+const writeUpdate = (version) => {
+  const helper = fs.readFileSync('./lib/chromedriver.js', 'utf8');
+  const versionExport = 'exports.version';
+  const regex = new RegExp(`^.*${versionExport}.*$`, 'gm');
+  const updated = helper.replace(regex, `${versionExport} = '${version}';`);
+  fs.writeFileSync('./lib/chromedriver.js', updated, 'utf8');
+  const packageVersion = `${version.slice(0, 2)}.0.0`;
+  execSync(`npm version ${packageVersion} --git-tag-version=false && git add . && git commit -m "Bump version to ${packageVersion}" && git tag ${packageVersion}`);
+};
+
+getLatest((version) => {
+  if (CURRENT_VERSION === version) {
+    console.log('Chromedriver version is up to date.');
+  } else {
+    writeUpdate(version);
+    console.log(`Chromedriver version updated to ${version}`);
+  }
+});