add setupBrowserTransport tests

Author: Lms24

packages/browser/src/transports/setup.ts

@@ -46,6 +46,7 @@ export function setupBrowserTransport(options: BrowserOptions): { transport: Tra
   if (options.transport) {
     return { transport: new options.transport(transportOptions) };
   }
+
   if (supportsFetch()) {
     const requestOptions: RequestInit = { ...transportOptions.fetchParameters };
     const newTransport = makeNewFetchTransport({ requestOptions, url });

packages/browser/test/unit/transports/setup.test.ts

@@ -0,0 +1,87 @@
+import { NoopTransport } from '@sentry/core';
+import { FetchTransport, setupBrowserTransport, XHRTransport } from '../../../src/transports';
+import { SimpleTransport } from '../mocks/simpletransport';
+
+const DSN = 'https://username@domain/123';
+
+let fetchSupported = true;
+let getNativeFetchImplCalled = false;
+
+jest.mock('@sentry/utils', () => {
+  const original = jest.requireActual('@sentry/utils');
+  return {
+    ...original,
+    supportsFetch(): boolean {
+      return fetchSupported;
+    },
+    getGlobalObject(): any {
+      return {
+        fetch: () => {},
+      };
+    },
+  };
+});
+
+jest.mock('@sentry/browser/src/transports/utils', () => {
+  const original = jest.requireActual('@sentry/browser/src/transports/utils');
+  return {
+    ...original,
+    getNativeFetchImplementation() {
+      getNativeFetchImplCalled = true;
+      return {
+        fetch: () => {},
+      };
+    },
+  };
+});
+
+describe('setupBrowserTransport', () => {
+  beforeEach(() => {
+    getNativeFetchImplCalled = false;
+  });
+
+  it('returns NoopTransport if no dsn is passed', () => {
+    const { transport, newTransport } = setupBrowserTransport({});
+
+    expect(transport).toBeDefined();
+    expect(transport).toBeInstanceOf(NoopTransport);
+    expect(newTransport).toBeUndefined();
+  });
+
+  it('returns the instantiated transport passed via the options', () => {
+    const options = { dsn: DSN, transport: SimpleTransport };
+    const { transport, newTransport } = setupBrowserTransport(options);
+
+    expect(transport).toBeDefined();
+    expect(transport).toBeInstanceOf(SimpleTransport);
+    expect(newTransport).toBeUndefined();
+  });
+
+  it('returns fetchTransports if fetch is supported', () => {
+    const options = { dsn: DSN };
+    const { transport, newTransport } = setupBrowserTransport(options);
+
+    expect(transport).toBeDefined();
+    expect(transport).toBeInstanceOf(FetchTransport);
+    expect(newTransport).toBeDefined();
+    // This is a weird way of testing that `newTransport` is using fetch but it works.
+    // Given that the new transports are functions, we cannot test their instance.
+    // Totally open for suggestions how to test this better here
+    expect(getNativeFetchImplCalled).toBe(true);
+  });
+
+  it('returns xhrTransports if fetch is not supported', () => {
+    fetchSupported = false;
+
+    const options = { dsn: DSN };
+    const { transport, newTransport } = setupBrowserTransport(options);
+
+    expect(transport).toBeDefined();
+    expect(transport).toBeInstanceOf(XHRTransport);
+    expect(newTransport).toBeDefined();
+    // This is a weird way of testing that `newTransport` is using fetch but it works.
+    // Given that the new transports are functions, we cannot test their instance.
+    // Totally open for suggestions how to test this better here
+    expect(getNativeFetchImplCalled).toBe(false);
+  });
+});