Replace External URL testErrorPageRedirect with hermetic test.

Old test was loading http://mock/bad and because this URL did not
exist the load was failing because of DNS resolution error.

New test uses EmbeddedTestServer, which closes the socket to simulate
ERR_INTERNET_DISCONNECTED error.

Bug: 694662
Cq-Include-Trybots: master.tryserver.chromium.mac:ios-simulator-cronet;master.tryserver.chromium.mac:ios-simulator-full-configs
Change-Id: Iaca523e8153a2c4cca0e1f174652ed48f22cabd3
Reviewed-on: https://chromium-review.googlesource.com/1035610
Commit-Queue: Eugene But <eugenebut@chromium.org>
Reviewed-by: Danyao Wang <danyao@chromium.org>
Cr-Commit-Position: refs/heads/master@{#555316}

ios/chrome/browser/ui/external_url_error_page_egtest.mm

@@ -52,31 +52,6 @@ using web::test::HttpServer;
 
 #pragma mark - tests
 
-// Tests whether the error page is displayed if it is behind a redirect.
-- (void)testErrorPageRedirect {
-// TODO(crbug.com/694662): This test relies on external URL because of the bug.
-// Re-enable this test on device once the bug is fixed.
-#if !TARGET_IPHONE_SIMULATOR
-  EARL_GREY_TEST_DISABLED(@"Test disabled on device.");
-#endif
-
-  std::unique_ptr<web::DataResponseProvider> provider(
-      new ErrorPageResponseProvider());
-  web::test::SetUpHttpServer(std::move(provider));
-
-  // Load a URL that redirects to the DNS-failing URL.
-  [ChromeEarlGrey
-      loadURL:ErrorPageResponseProvider::GetRedirectToDnsFailureUrl()];
-
-  // Verify that the redirect occurred before checking for the DNS error.
-  const std::string& redirectedURL =
-      ErrorPageResponseProvider::GetDnsFailureUrl().GetContent();
-  [[EarlGrey selectElementWithMatcher:OmniboxText(redirectedURL)]
-      assertWithMatcher:grey_notNil()];
-
-  [ChromeEarlGrey waitForErrorPage];
-}
-
 // Tests that the error page is not displayed if the bad URL is in a <iframe>
 // tag.
 - (void)testErrorPageInIFrame {

ios/chrome/browser/web/error_page_egtest.mm

@@ -10,6 +10,7 @@
 #include "base/strings/sys_string_conversions.h"
 #import "ios/chrome/test/earl_grey/chrome_earl_grey.h"
 #import "ios/chrome/test/earl_grey/chrome_test_case.h"
+#include "net/test/embedded_test_server/default_handlers.h"
 #include "net/test/embedded_test_server/http_request.h"
 #include "net/test/embedded_test_server/http_response.h"
 
@@ -38,21 +39,26 @@ NSString* GetErrorMessage() {
 - (void)setUp {
   [super setUp];
 
-  // Tests handler which replies with URL query if serverRespondsWithContent set
-  // to YES. Otherwise the handler closes the socket.
+  // Tests handler which replies with URL query for /echo-query path if
+  // serverRespondsWithContent set to YES. Otherwise the handler closes the
+  // socket.
   using net::test_server::HttpRequest;
   using net::test_server::HttpResponse;
   auto handler = ^std::unique_ptr<HttpResponse>(const HttpRequest& request) {
-    if (!self.serverRespondsWithContent) {
-      return std::make_unique<net::test_server::RawHttpResponse>(
-          /*headers=*/"", /*contents=*/"");
+    if (request.GetURL().path() == "/echo-query") {
+      if (!self.serverRespondsWithContent) {
+        return std::make_unique<net::test_server::RawHttpResponse>(
+            /*headers=*/"", /*contents=*/"");
+      }
+      auto response = std::make_unique<net::test_server::BasicHttpResponse>();
+      response->set_content_type("text/html");
+      response->set_content(request.GetURL().query());
+      return std::move(response);
     }
-    auto response = std::make_unique<net::test_server::BasicHttpResponse>();
-    response->set_content_type("text/html");
-    response->set_content(request.GetURL().query());
-    return std::move(response);
+    return nullptr;
   };
   self.testServer->RegisterDefaultHandler(base::BindBlockArc(handler));
+  RegisterDefaultHandlers(self.testServer);
 
   GREYAssertTrue(self.testServer->Start(), @"Test server failed to start.");
 }
@@ -61,7 +67,7 @@ NSString* GetErrorMessage() {
 - (void)testReload {
   // No response leads to ERR_INTERNET_DISCONNECTED error.
   self.serverRespondsWithContent = NO;
-  [ChromeEarlGrey loadURL:self.testServer->GetURL("/?foo")];
+  [ChromeEarlGrey loadURL:self.testServer->GetURL("/echo-query?foo")];
   [ChromeEarlGrey waitForStaticHTMLViewContainingText:GetErrorMessage()];
 
   // Reload the page, which should load without errors.
@@ -70,4 +76,13 @@ NSString* GetErrorMessage() {
   [ChromeEarlGrey waitForWebViewContainingText:"foo"];
 }
 
+// Loads the URL which redirects to unresponsive server.
+- (void)testRedirectToFailingURL {
+  // No response leads to ERR_INTERNET_DISCONNECTED error.
+  self.serverRespondsWithContent = NO;
+  [ChromeEarlGrey
+      loadURL:self.testServer->GetURL("/server-redirect?echo-query")];
+  [ChromeEarlGrey waitForStaticHTMLViewContainingText:GetErrorMessage()];
+}
+
 @end

ios/web/public/test/http_server/error_page_response_provider.h

@@ -12,8 +12,6 @@
 #include "url/gurl.h"
 
 // A HtmlResponseProvider that supports the following additional URLs:
-// - GetRedirectToDnsFailureUrl - the response is a redirect to
-//   |GetDnsFailureUrl|.
 // - GetDnsFailureUrl - triggers a DNS error.
 class ErrorPageResponseProvider : public HtmlResponseProvider {
  public:
@@ -23,15 +21,6 @@ class ErrorPageResponseProvider : public HtmlResponseProvider {
       : HtmlResponseProvider(responses) {}
   // Returns a URL that causes a DNS failure.
   static GURL GetDnsFailureUrl();
-  // Returns a URL that redirects to a bad URL.
-  static GURL GetRedirectToDnsFailureUrl();
-
-  // HtmlResponseProvider implementation.
-  bool CanHandleRequest(const Request& request) override;
-  void GetResponseHeadersAndBody(
-      const Request& request,
-      scoped_refptr<net::HttpResponseHeaders>* headers,
-      std::string* response_body) override;
 };
 
 #endif  // IOS_WEB_PUBLIC_TEST_HTTP_SERVER_ERROR_PAGE_RESPONSE_PROVIDER_H_

ios/web/public/test/http_server/error_page_response_provider.mm

@@ -4,10 +4,6 @@
 
 #import "ios/web/public/test/http_server/error_page_response_provider.h"
 
-#include "base/logging.h"
-#import "ios/web/public/test/http_server/http_server.h"
-#include "net/http/http_status_code.h"
-
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."
 #endif
@@ -16,30 +12,3 @@
 GURL ErrorPageResponseProvider::GetDnsFailureUrl() {
   return GURL("http://mock/bad");
 }
-
-// static
-GURL ErrorPageResponseProvider::GetRedirectToDnsFailureUrl() {
-  return web::test::HttpServer::MakeUrl("http://mock/redirect");
-}
-
-// Returns true for |RedirectToDnsFailureUrl|.
-bool ErrorPageResponseProvider::CanHandleRequest(const Request& request) {
-  return (HtmlResponseProvider::CanHandleRequest(request) ||
-          request.url ==
-              ErrorPageResponseProvider::GetRedirectToDnsFailureUrl());
-}
-
-void ErrorPageResponseProvider::GetResponseHeadersAndBody(
-    const Request& request,
-    scoped_refptr<net::HttpResponseHeaders>* headers,
-    std::string* response_body) {
-  if (HtmlResponseProvider::CanHandleRequest(request)) {
-    HtmlResponseProvider::GetResponseHeadersAndBody(request, headers,
-                                                    response_body);
-  } else if (request.url == GetRedirectToDnsFailureUrl()) {
-    *headers = web::ResponseProvider::GetRedirectResponseHeaders(
-        ErrorPageResponseProvider::GetDnsFailureUrl().spec(), net::HTTP_FOUND);
-  } else {
-    NOTREACHED();
-  }
-}