chore(tests): better sentry tests with real package instead of a mock

ui/__mocks__/@sentry/browser.js

@@ -1,10 +0,0 @@
-const init = jest.fn();
-const MockScope = {
-  setExtra: jest.fn()
-};
-const configureScope = jest.fn().mockImplementation(fn => {
-  fn(MockScope);
-});
-const captureException = jest.fn();
-
-export { init, configureScope, captureException, MockScope };

ui/src/AppBoot.js

@@ -19,7 +19,7 @@ const SetupSentry = settingsElement => {
     }
 
     try {
-      return Sentry.init({
+      Sentry.init({
         dsn: settingsElement.dataset.sentryDsn,
         release: version
       });
@@ -27,7 +27,6 @@ const SetupSentry = settingsElement => {
       console.error("Sentry config failed: " + err);
     }
   }
-  return null;
 };
 
 const ParseDefaultFilters = settingsElement => {

ui/src/AppBoot.test.js

@@ -2,10 +2,14 @@ import * as Sentry from "@sentry/browser";
 
 import { SettingsElement, SetupSentry, ParseDefaultFilters } from "./AppBoot";
 
-beforeEach(() => {
-  Sentry.init.mockReset();
+afterEach(() => {
+  // reset sentry state before each mock, that's the only way to revert
+  // Sentry.init() that I found
+  global.__SENTRY__ = {};
 });
 
+const FakeDSN = "https://81a9ef37a6ed4fdb80e9ea2310d1ed28@127.0.0.1/1234123";
+
 const MockSettings = (version, SentryDsn, defaultFilters) => {
   return jest.spyOn(document, "getElementById").mockImplementation(() => {
     const filtersBase64 = btoa(JSON.stringify(defaultFilters));
@@ -50,30 +54,30 @@ describe("SettingsElement()", () => {
 
 describe("SetupSentry()", () => {
   it("does nothing when Sentry DSN is missing", () => {
+    const sentrySpy = jest.spyOn(Sentry, "init");
     SentryClient("");
-    expect(Sentry.init).not.toHaveBeenCalled();
+    expect(sentrySpy).not.toHaveBeenCalled();
   });
 
   it("configures Sentry when DSN is present", () => {
-    SentryClient("https://key@example.com/mock");
-    expect(Sentry.init).toHaveBeenCalledWith({
-      dsn: "https://key@example.com/mock",
+    const sentrySpy = jest.spyOn(Sentry, "init");
+    SentryClient(FakeDSN);
+    expect(sentrySpy).toHaveBeenCalledWith({
+      dsn: FakeDSN,
       release: "unknown" // default version
     });
   });
 
   it("passes release option when version attr is present", () => {
-    SentryClient("https://key@example.com/mock", "ver1");
-    expect(Sentry.init).toHaveBeenCalledWith({
-      dsn: "https://key@example.com/mock",
+    const sentrySpy = jest.spyOn(Sentry, "init");
+    SentryClient(FakeDSN, "ver1");
+    expect(sentrySpy).toHaveBeenCalledWith({
+      dsn: FakeDSN,
       release: "ver1"
     });
   });
 
   it("logs an error when invalid DSN is passed to Sentry", () => {
-    Sentry.init = jest.fn().mockImplementation(() => {
-      throw new Error("Fake error");
-    });
     const consoleSpy = jest
       .spyOn(console, "error")
       .mockImplementation(() => {});

ui/src/ErrorBoundary.test.js

@@ -8,13 +8,12 @@ import * as Sentry from "@sentry/browser";
 
 import { ErrorBoundary } from "./ErrorBoundary";
 
-beforeAll(() => {
+beforeEach(() => {
   jest.useFakeTimers();
 });
 
 afterEach(() => {
   jest.clearAllTimers();
-  jest.clearAllMocks();
 });
 
 const FailingComponent = () => {
@@ -42,11 +41,15 @@ describe("<ErrorBoundary />", () => {
   });
 
   it("componentDidCatch should report to sentry", () => {
+    const sentrySpy = jest.spyOn(Sentry, "captureException");
     MountedFailingComponent();
-    expect(Sentry.captureException).toHaveBeenCalled();
+    expect(sentrySpy).toHaveBeenCalled();
   });
 
   it("componentDidCatch passes scope to sentry", () => {
+    const sentrySpy = jest.spyOn(Sentry, "configureScope");
+    Sentry.init({ dsn: "https://foobar@localhost/123456" });
+
     const tree = mount(
       <ErrorBoundary>
         <div />
@@ -54,7 +57,7 @@ describe("<ErrorBoundary />", () => {
     );
     const instance = tree.instance();
     instance.componentDidCatch("foo", { foo: "bar" });
-    expect(Sentry.MockScope.setExtra).toHaveBeenCalledWith("foo", "bar");
+    expect(sentrySpy).toHaveBeenCalled();
   });
 
   it("calls window.location.reload after 60s", () => {