Wait for a Page event before collecting events

example/simple.js

@@ -0,0 +1,17 @@
+const puppeteer = require('puppeteer');
+const PuppeteerHar = require('../');
+
+(async () => {
+    const browser = await puppeteer.launch();
+    const page = await browser.newPage();
+
+    const har = new PuppeteerHar(page);
+    await har.start();
+
+    await page.goto('http://www.yahoo.com');
+
+    const harResult = await har.stop();
+    console.log(JSON.stringify(harResult, null, 2));
+
+    await browser.close();
+})();

lib/PuppeteerHar.js

@@ -6,15 +6,16 @@ const { harFromMessages } = require('chrome-har');
 const observe = [
     'Page.loadEventFired',
     'Page.domContentEventFired',
-    'Page.frameStartedLoading',
     'Page.frameAttached',
+    'Page.frameStartedLoading',
+    'Page.frameScheduledNavigation',
     'Network.requestWillBeSent',
     'Network.requestServedFromCache',
-    'Network.dataReceived',
     'Network.responseReceived',
-    'Network.resourceChangedPriority',
+    'Network.dataReceived',
     'Network.loadingFinished',
     'Network.loadingFailed',
+    'Network.resourceChangedPriority'
 ];
 
 class PuppeteerHar {
@@ -24,7 +25,6 @@ class PuppeteerHar {
      */
     constructor(page) {
         this.page = page;
-        this.mainFrame = this.page.mainFrame();
         this.events = [];
     }
 
@@ -37,9 +37,24 @@ class PuppeteerHar {
         this.client = await this.page.target().createCDPSession();
         await this.client.send('Page.enable');
         await this.client.send('Network.enable');
+        let haveSeenPageEvent = false;
+        let holdUntilPageEvent = [];
         observe.forEach(async method => {
             await this.client.on(method, params => {
-                this.events.push({ method, params });
+                // these are the methods that chrome-har adds a page entry for
+                if (method === 'Page.frameStartedLoading' || method === 'Page.frameScheduledNavigation') {
+                    haveSeenPageEvent = true;
+                }
+
+                if (!haveSeenPageEvent) {
+                    holdUntilPageEvent.push({ method, params })
+                } else {
+                    this.events.push({ method, params });
+                    if (holdUntilPageEvent.length > 0) {
+                        this.events = this.events.concat(holdUntilPageEvent);
+                        holdUntilPageEvent = []
+                    }
+                }
             });
         });
     }