test: add test for get note interceptor

Signed-off-by: Tilman Vatteroth <git@tilmanvatteroth.de>

backend/src/api/utils/get-note.interceptor.spec.ts

@@ -0,0 +1,85 @@
+/*
+ * SPDX-FileCopyrightText: 2023 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+import { CallHandler, ExecutionContext } from '@nestjs/common';
+import { HttpArgumentsHost } from '@nestjs/common/interfaces/features/arguments-host.interface';
+import { Observable } from 'rxjs';
+import { Mock } from 'ts-mockery';
+
+import { Note } from '../../notes/note.entity';
+import { NotesService } from '../../notes/notes.service';
+import { GetNoteInterceptor } from './get-note.interceptor';
+import { CompleteRequest } from './request.type';
+
+describe('get note interceptor', () => {
+  const mockNote = Mock.of<Note>({});
+  const mockNoteId = 'noteIdOrAlias';
+  const mockObservable = Mock.of<Observable<unknown>>({});
+  const nextCallHandler = Mock.of<CallHandler>({
+    handle: () => mockObservable,
+  });
+
+  let notesService: NotesService;
+  let noteFetchSpy: jest.SpyInstance;
+
+  beforeEach(() => {
+    notesService = Mock.of<NotesService>({
+      getNoteByIdOrAlias: (id) =>
+        id === mockNoteId ? Promise.resolve(mockNote) : Promise.reject(),
+    });
+    noteFetchSpy = jest.spyOn(notesService, 'getNoteByIdOrAlias');
+  });
+
+  function mockExecutionContext(request: CompleteRequest) {
+    return Mock.of<ExecutionContext>({
+      switchToHttp: () =>
+        Mock.of<HttpArgumentsHost>({
+          getRequest: () => request,
+        }),
+    });
+  }
+
+  it('extracts the note from the request headers', async () => {
+    const request = Mock.of<CompleteRequest>({
+      params: {},
+      headers: { ['hedgedoc-note']: mockNoteId },
+    });
+    const context = mockExecutionContext(request);
+    const sut: GetNoteInterceptor = new GetNoteInterceptor(notesService);
+    const result = await sut.intercept(context, nextCallHandler);
+
+    expect(result).toBe(mockObservable);
+    expect(request.note).toBe(mockNote);
+    expect(noteFetchSpy).toHaveBeenCalledTimes(1);
+  });
+
+  it('extracts the note from the request parameters', async () => {
+    const request = Mock.of<CompleteRequest>({
+      params: { noteIdOrAlias: mockNoteId },
+    });
+    const context = mockExecutionContext(request);
+    const sut: GetNoteInterceptor = new GetNoteInterceptor(notesService);
+    const result = await sut.intercept(context, nextCallHandler);
+
+    expect(result).toBe(mockObservable);
+    expect(request.note).toBe(mockNote);
+    expect(noteFetchSpy).toHaveBeenCalledTimes(1);
+  });
+
+  it('works if no note id is in the request', async () => {
+    const request = Mock.of<CompleteRequest>({
+      params: {},
+      headers: {},
+    });
+
+    const context = mockExecutionContext(request);
+    const sut: GetNoteInterceptor = new GetNoteInterceptor(notesService);
+    const result = await sut.intercept(context, nextCallHandler);
+
+    expect(result).toBe(mockObservable);
+    expect(request.note).toBe(undefined);
+    expect(noteFetchSpy).toHaveBeenCalledTimes(0);
+  });
+});