Fix PageGotoTests (#2238)

* Fix PageGotoTests' flakyness.

See puppeteer/puppeteer#8717

* Fix PageGotoTests.ShouldWorkWhenNavigatingTo404 when executed in headful mode.

See puppeteer/puppeteer#9577

Author: leonardo-fernandes

lib/PuppeteerSharp.Tests/NavigationTests/PageGotoTests.cs

@@ -294,6 +294,36 @@ public async Task ShouldWorkWhenNavigatingTo404()
             Assert.Equal(HttpStatusCode.NotFound, response.Status);
         }
 
+        [PuppeteerTest("navigation.spec.ts", "Page.goto", "should not throw an error for a 404 response with an empty body")]
+        [PuppeteerFact]
+        public async Task ShouldNotThrowAnErrorForA404ResponseWithAnEmptyBody()
+        {
+            Server.SetRoute("/404-error", context =>
+            {
+                context.Response.StatusCode = 404;
+                return Task.CompletedTask;
+            });
+
+            var response = await Page.GoToAsync(TestConstants.ServerUrl + "/404-error");
+            Assert.False(response.Ok);
+            Assert.Equal(HttpStatusCode.NotFound, response.Status);
+        }
+
+        [PuppeteerTest("navigation.spec.ts", "Page.goto", "should not throw an error for a 500 response with an empty body")]
+        [PuppeteerFact]
+        public async Task ShouldNotThrowAnErrorForA500ResponseWithAnEmptyBody()
+        {
+            Server.SetRoute("/500-error", context =>
+            {
+                context.Response.StatusCode = 500;
+                return Task.CompletedTask;
+            });
+
+            var response = await Page.GoToAsync(TestConstants.ServerUrl + "/500-error");
+            Assert.False(response.Ok);
+            Assert.Equal(HttpStatusCode.InternalServerError, response.Status);
+        }
+
         [PuppeteerTest("navigation.spec.ts", "Page.goto", "should return last response in redirect chain")]
         [PuppeteerFact]
         public async Task ShouldReturnLastResponseInRedirectChain()

lib/PuppeteerSharp/FrameManager.cs

@@ -193,7 +193,7 @@ private async Task NavigateAsync(CDPSession client, string url, string referrer,
 
             _ensureNewDocumentNavigation = !string.IsNullOrEmpty(response.LoaderId);
 
-            if (!string.IsNullOrEmpty(response.ErrorText))
+            if (!string.IsNullOrEmpty(response.ErrorText) && response.ErrorText != "net::ERR_HTTP_RESPONSE_CODE_FAILURE")
             {
                 throw new NavigationException(response.ErrorText, url);
             }