tags.test.js

const request = require("supertest");
const { Tag } = require("../../models/tag");
const Server = require("../../index");

let server;

describe("/api/tags", () => {

  afterEach(async () => {

    await Tag.remove({});
  });

  describe("GET /", () => {
    it("should return all tags", async () => {
      server = Server()
      await Tag.collection.insertMany([
        { name: "tag1" },
        { name: "tag2" },
        { name: "tag3" }
      ]);

      const res = await request(server).get("/api/tags");
      console.log(res.body);
      expect(res.status).toBe(200);
      expect(res.body.length).toBe(3);
      expect(res.body.some(t => t.name === "tag1")).toBeTruthy();
      expect(res.body.some(t => t.name === "tag2")).toBeTruthy();
      expect(res.body.some(t => t.name === "tag3")).toBeTruthy();
    });
    server.close()
  });

See lines 3, 16, 31