doc(troubleshooting): add note about lack of node 8 support (#623)

docs/troubleshooting.md

@@ -12,6 +12,7 @@
   * [Running Playwright in Docker](#running-playwright-in-docker)
     - [Tips](#tips)
 - [Code Transpilation Issues](#code-transpilation-issues)
+- [ReferenceError: URL is not defined](#referenceerror-url-is-not-defined)
 <!-- GEN:stop -->
 ## Chromium
 
@@ -288,6 +289,10 @@ await page.evaluate(`(async() => {
 })()`);
 ```
 
+## ReferenceError: URL is not defined
+
+Playwright requires node 10 or higher. Node 8 is not supported, and will cause you to recieve this error.
+
 # Please file an issue
 
 Playwright is a new project, and we are watching the issues very closely. As we solve common issues, this document will grow to include the common answers.

utils/doclint/check_public_api/JSBuilder.js

@@ -30,7 +30,7 @@ function checkSources(sources, externalDependencies) {
   const classEvents = new Map();
   const eventsSources = sources.filter(source => source.name().startsWith('events.ts'));
   for (const eventsSource of eventsSources) {
-    const {Events} = require(eventsSource.filePath().endsWith('.js') ? eventsSource.filePath() : eventsSource.filePath().replace('/src/', '/lib/').replace('.ts', '.js'));
+    const {Events} = require(eventsSource.filePath().endsWith('.js') ? eventsSource.filePath() : eventsSource.filePath().replace(/\bsrc\b/, 'lib').replace('.ts', '.js'));
     for (const [className, events] of Object.entries(Events))
       classEvents.set(className, Array.from(Object.values(events)).filter(e => typeof e === 'string').map(e => Documentation.Member.createEvent(e)));
   }