fix: page.goto should support pages with self requests (#1391) (#1781)

This patch fixes `page.goto` for websites that re-request document URL with javascript.

Fixes #1391.

lib/Page.js

@@ -494,7 +494,10 @@ class Page extends EventEmitter {
 
     const requests = new Map();
     const eventListeners = [
-      helper.addEventListener(this._networkManager, NetworkManager.Events.Request, request => requests.set(request.url(), request))
+      helper.addEventListener(this._networkManager, NetworkManager.Events.Request, request => {
+        if (!requests.get(request.url()))
+          requests.set(request.url(), request);
+      })
     ];
 
     const mainFrame = this._frameManager.mainFrame();

test/assets/self-request.html

@@ -0,0 +1,5 @@
+<script>
+var req = new XMLHttpRequest();
+req.open('GET', '/self-request.html');
+req.send(null);
+</script>

test/test.js

@@ -1193,6 +1193,11 @@ describe('Page', function() {
       expect(requests.length).toBe(1);
       expect(requests[0].url()).toBe(server.EMPTY_PAGE);
     });
+    it('should work with self requesting page', async({page, server}) => {
+      const response = await page.goto(server.PREFIX + '/self-request.html');
+      expect(response.status()).toBe(200);
+      expect(response.url()).toContain('self-request.html');
+    });
   });
 
   describe('Page.waitForNavigation', function() {