Section 2: services

Author: VLamartine

src/app/courses/services/courses.service.spec.ts

@@ -0,0 +1,129 @@
+import { COURSES, findLessonsForCourse } from "./../../../../server/db-data";
+import { TestBed } from "@angular/core/testing";
+import {
+  HttpClientTestingModule,
+  HttpTestingController,
+} from "@angular/common/http/testing";
+import { CoursesService } from "./courses.service";
+import { Course } from "../model/course";
+import { HttpErrorResponse } from "@angular/common/http";
+
+describe("CoursesService", () => {
+  let courseService: CoursesService;
+  let httpTestingController: HttpTestingController;
+
+  beforeEach(() => {
+    TestBed.configureTestingModule({
+      imports: [HttpClientTestingModule],
+      providers: [CoursesService],
+    });
+
+    courseService = TestBed.inject(CoursesService);
+    httpTestingController = TestBed.inject(HttpTestingController);
+  });
+
+  afterEach(() => {
+    httpTestingController.verify();
+  });
+
+  it("should retrieve all courses", () => {
+    courseService.findAllCourses().subscribe({
+      next: (courses) => {
+        expect(courses).toBeTruthy("No courses returned");
+        expect(courses.length).toBe(12, "Incorrect number of courses");
+        const course = courses.find((course) => course.id == 12);
+        expect(course.titles.description).toBe("Angular Testing Course");
+      },
+    });
+
+    const req = httpTestingController.expectOne("/api/courses");
+    expect(req.request.method).toEqual("GET");
+    req.flush({ payload: Object.values(COURSES) });
+  });
+
+  it("sould find a course by id", () => {
+    courseService.findCourseById(12).subscribe({
+      next: (course) => {
+        expect(course).toBeTruthy("No course found");
+        expect(course.id).toBe(12);
+        expect(course.titles.description).toBe("Angular Testing Course");
+      },
+    });
+
+    const req = httpTestingController.expectOne("/api/courses/12");
+    expect(req.request.method).toEqual("GET");
+    req.flush(COURSES[12]);
+  });
+
+  it("should save the course data", () => {
+    const changes: Partial<Course> = {
+      titles: { description: "Testing course" },
+    };
+    courseService.saveCourse(12, changes).subscribe({
+      next: (course) => {
+        expect(course.id).toBe(12);
+      },
+    });
+
+    const req = httpTestingController.expectOne("/api/courses/12");
+    expect(req.request.method).toEqual("PUT");
+    expect(req.request.body.titles.description).toEqual(
+      changes.titles.description
+    );
+
+    req.flush({
+      ...COURSES[12],
+      ...changes,
+    });
+  });
+
+  it("sould give an error if save course fails", () => {
+    const changes: Partial<Course> = {
+      titles: { description: "Testing course" },
+    };
+
+    courseService.saveCourse(12, changes).subscribe({
+      next: () => {
+        fail("The save course should have failed");
+      },
+      error: (error: HttpErrorResponse) => {
+        expect(error.status).toBe(500);
+      },
+    });
+    const req = httpTestingController.expectOne("/api/courses/12");
+    expect(req.request.method).toEqual("PUT");
+    expect(req.request.body.titles.description).toEqual(
+      changes.titles.description
+    );
+
+    req.flush("Save course failed", {
+      status: 500,
+      statusText: "InternalServerError",
+    });
+  });
+
+  it("should find a list of lessons", () => {
+    courseService.findLessons(12).subscribe({
+      next: (lessons) => {
+        expect(lessons).toBeTruthy();
+        expect(lessons.length).toBe(3);
+      },
+    });
+
+    const req = httpTestingController.expectOne(
+      (req) => req.url === "/api/lessons"
+    );
+
+    expect(req.request.method).toEqual("GET");
+
+    expect(req.request.params.get("courseId")).toEqual("12");
+    expect(req.request.params.get("filter")).toEqual("");
+    expect(req.request.params.get("sortOrder")).toEqual("asc");
+    expect(req.request.params.get("pageNumber")).toEqual("0");
+    expect(req.request.params.get("pageSize")).toEqual("3");
+
+    req.flush({
+      payload: findLessonsForCourse(12).slice(0, 3),
+    });
+  });
+});