fe-middleware/test/imageService.test.ts

import { afterEach, describe, expect, it, jest, spyOn } from "bun:test";
import app from "src/app";
import * as botApiService from "src/services/botApiService";
import * as gelbooruApiService from "src/services/gelbooruApiService";
import * as imageService from "src/services/imageService";
import Image from "src/types/Image";
import request from "supertest";

afterEach(() => {
  jest.restoreAllMocks();
})

describe("the service is thread-safe", () => {
  it("should not crash when multiple processes call the get() method simultaneously", async () => {
    const NUM_OF_REQUESTS = 110;

    const getFn = spyOn(imageService, "get");

    const promises = Array(NUM_OF_REQUESTS).fill(null)
      .map(_ => request(app).get("/image"));
    const responses = await Promise.all(promises);

    expect(getFn).toHaveBeenCalledTimes(NUM_OF_REQUESTS);
    responses.forEach(res => expect(res.status).toBe(200));
  })
})

describe("endpoint gets a non repeated image", () => {
  it("should return an image that is not in the response of the /images endpoint of the bot API", async () => {
    const REPEATED_URL =
      "https://fastly.picsum.photos/id/1/10/20.jpg?hmac=gY6PvUXFacKfYpBpTTVcNLxumpyMmoCamM-J5DOPwNc";
    const UNIQUE_URL =
      "https://fastly.picsum.photos/id/2/10/20.jpg?hmac=zy6lz21CuRIstr9ETx9h5AuoH50s_L2uIEct3dROpY8";

    const gelbooruApiServiceGet = spyOn(gelbooruApiService, "get");
    gelbooruApiServiceGet.mockImplementationOnce(async () => ({ posts: [{ url: UNIQUE_URL, tags: [] }] }));
    gelbooruApiServiceGet.mockImplementation(async () => ({ posts: [{ url: REPEATED_URL, tags: [] }] }));
    spyOn(botApiService, "getAll").mockImplementation(async () => ({
      images: [
        {
          _id: "0",
          url: REPEATED_URL,
          status: "consumed",
          tags: ["pokemon", "computer"],
          __v: 0,
        },
      ],
    }));

    const image: Image = await imageService.get();

    expect(image.url).not.toBe(REPEATED_URL);
  });
});