config_service: Handled errors in the front page

appengine/config_service/ui/test/config-ui/front-page_test.html

Index: appengine/config_service/ui/test/config-ui/front-page_test.html
diff --git a/appengine/config_service/ui/test/config-ui/front-page_test.html b/appengine/config_service/ui/test/config-ui/front-page_test.html
index 6c7f1e8d3b42006b43920b46449ed2fe989e0c19..8b54a18e7542b93836c2a4cf39efae2ee0510d6d 100644
--- a/appengine/config_service/ui/test/config-ui/front-page_test.html
+++ b/appengine/config_service/ui/test/config-ui/front-page_test.html
@@ -143,6 +143,103 @@
           }.bind(front_page));
         });
       });
+
+      suite('Front page handles ajax errors correctly', function() {
+        var ajax;
+        var request;
+        var server500;
+        var server403;
+        var server400;
+        var responseHeaders = {
+          json: { 'Content-Type': 'application/json' }
+        };
+        var front_page;
+        setup(function() {
+          server500 = sinon.fakeServer.create();

[Sergey Berezin, 2017/07/26 23:09:13]

Suggestion: instead of using setup(), how about creating a separate helper
function within the suite which creates and returns a new fake server based on
the desired return code and the error message.
Then each test calls this helper to get its local copy of the test server. This
way, you only write the boilerplate once, and there is no need to .restore() it
at the end.

+          var param500 = {
+            error: {
+              code: 500,
+              message: "Internal Server Error."
+            }
+          }
+          server500.respondWith(
+            'GET',
+            /\/_ah\/api\/config\/v1\/config-sets\?include_last_import_attempt=true/, 
+            [
+              500,
+              responseHeaders.json,
+              JSON.stringify(param500)
+            ]
+          );
+
+          server403 = sinon.fakeServer.create();
+          var param403 = {
+            error: {
+              code: 403,
+              message: "The request returned with a status of 403."
+            }
+          }
+          server403.respondWith(
+            'GET',
+            /\/_ah\/api\/config\/v1\/config-sets\?include_last_import_attempt=true/, 
+            [
+              403,
+              responseHeaders.json,
+              JSON.stringify(param403)
+            ]
+          );
+
+          server400 = sinon.fakeServer.create();
+          var param400 = {
+            error: {
+              code: 400,
+              message: "This error represents all errors that are not forbidden or internal server errors."
+            }
+          }
+          server400.respondWith(
+            'GET',
+            /\/_ah\/api\/config\/v1\/config-sets\?include_last_import_attempt=true/, 
+            [
+              400,
+              responseHeaders.json,
+              JSON.stringify(param400)
+            ]
+          );
+          front_page = fixture('front-pageTestFixture');
+          ajax = Polymer.dom(front_page.root).querySelector('iron-ajax');
+        });
+
+        teardown(function() {
+          server500.restore();
+          server403.restore();
+          server400.restore();
+        });
+
+        test('front page handles 500 error', function() {
+          request = ajax.generateRequest();
+          server500.respond();
+          front_page.addEventListener('fetchError', function() {
+            expect(front_page.errorMessage).to.be
+                .equal("Internal server error. Please refresh or try again later.");
+          })
+        });
+
+        test('front page handles 403 error', function() {
+          request = ajax.generateRequest();
+          server403.respond();
+          front_page.addEventListener('fetchError', function() {
+            expect(front_page.errorMessage).to.be.equal("Access denied.");
+          })
+        });
+
+        test('front page handles error that is not 403 or 500', function() {
+          request = ajax.generateRequest();
+          server400.respond();
+          front_page.addEventListener('fetchError', function() {
+            expect(front_page.errorMessage).to.be.equal("Error occured. Please try again later.");
+          })
+        });
+      });
     </script>
   </body>
 </html>