Add option to choose which browser to use (chrome or firefox)

Fixes #1

Author: bramus

README.md

@@ -41,6 +41,27 @@ This will run the benchmark served by `http://localhost:3000/benchmarks/example/
 
 Note: You can also run benchmarks directly in a browser. To do so, visit its URL and invoke `window.startTest().then(console.table);` on the Console.
 
+### Choosing which browser to run the benchmarks in
+
+To select which browser to test things in, use the `--browser` option.
+
+```bash
+npm run benchmark example -- --browser=firefox
+```
+
+Supported options:
+
+- `chrome` = Use Chrome
+- `firefox`= Use Firefox
+
+The default used browser is `chrome`.
+
+A note will be printed on screen to show which version you are using. For example:
+
+```
+ℹ️ Running benchmark using browser firefox (firefox/129.0a1)
+```
+
 ## Creating a benchmark
 
 Benchmarks are HTML pages stored in a subfolder in `./src/benchmarks/`. The page **MUST** expose a `window.startTest` method which returns a promise. When the test logic is done, it **MUST** resolve that promise.

cli/index.js

@@ -5,24 +5,54 @@
 
 import puppeteer from 'puppeteer';
 
-if (!process.argv[2]) {
-	console.error('❌ Missing test argument');
+const args = process.argv.slice(2);
+const flags = args.filter(a => a.startsWith('--'));
+const params = args.filter(a => !a.startsWith('--'));
+
+// Determine which page to use
+if (!params.length) {
+	console.error('❌ Missing benchmark argument.');
 	process.exit(1);
 }
-
 const pageUrl = `http://localhost:3000/benchmarks/${process.argv[2]}`.trim();
 
+// Determine which browser to use
+const supportedBrowsers = ['chrome', 'firefox'];
+let requestedBrowser = flags.filter(f => f.startsWith('--browser=')).reduce((p, c) => `${p}${c}`, '');
+if (requestedBrowser) {
+	requestedBrowser = requestedBrowser.replace('--browser=', '');
+
+	if (!supportedBrowsers.includes(requestedBrowser)) {
+		console.error(`❌ Invalid browser. Only accepted values are ${supportedBrowsers.join(', ')}`);
+		process.exit(1);
+	}
+} else {
+	requestedBrowser = supportedBrowsers[0];
+}
+
+const puppeteerOptions = {
+	'chrome': {
+		headless: 'new',
+		args: [
+			"--flag-switches-begin",
+			"--enable-experimental-web-platform-features",
+			"--flag-switches-end",
+		],
+	},
+	'firefox': {
+
+	},
+};
+
 const browser = await puppeteer.launch({
-	headless: 'new',
-	product: 'chrome',
+	product: requestedBrowser,
 	protocol: 'webDriverBiDi',
-	args:[
-		"--flag-switches-begin",
-		"--enable-experimental-web-platform-features",
-		"--flag-switches-end",
-	],
+	...puppeteerOptions[requestedBrowser],
 });
 
+const browserVersion = await browser.version();
+console.info(`ℹ️ Running benchmark using browser ${requestedBrowser} (${browserVersion})`);
+
 const page = await browser.newPage();
 
 // Pipe Console output and errors to CLI
@@ -34,13 +64,14 @@ page.on('console', (message) => {
 
 // Catch server not running
 page.on('requestfailed', (request) => {
-	console.error(`❌ ${request.failure().errorText} ${request.url()}`);
 
 	switch (request.failure().errorText) {
 		case 'net::ERR_CONNECTION_REFUSED':
-			console.info('ℹ️ Please start the webserver first by running `npm run start`');
+			console.error(`❌ Could not connect to server`);
+			console.info('ℹ️ Please start the webserver first by running `npm run start` in parallel');
 			break;
 		default:
+			console.error(`❌ ${request.failure().errorText} ${request.url()}`);
 			break;
 	}
 	process.exit(1);