code-server/test/unit/browser/pages/login.test.ts

import { JSDOM } from "jsdom"
import { LocationLike } from "../../util.test"

describe("login", () => {
  describe("there is an element with id 'base'", () => {
    beforeEach(() => {
      const dom = new JSDOM()
      global.document = dom.window.document

      const location: LocationLike = {
        pathname: "/healthz",
        origin: "http://localhost:8080",
      }

      global.location = location as Location
    })
    afterEach(() => {
      // Reset the global.document
      global.document = undefined as any as Document
      global.location = undefined as any as Location
    })
    it("should set the value to options.base", () => {
      // Mock getElementById
      const spy = jest.spyOn(document, "getElementById")
      // Create a fake element and set the attribute
      const mockElement = document.createElement("input")
      mockElement.setAttribute("id", "base")
      const expected = {
        base: "./hello-world",
        csStaticBase: "./static/development/Users/jp/Dev/code-server",
        logLevel: 2,
        disableTelemetry: false,
        disableUpdateCheck: false,
      }
      mockElement.setAttribute("data-settings", JSON.stringify(expected))
      document.body.appendChild(mockElement)
      spy.mockImplementation(() => mockElement)
      // Load file
      require("../../../../src/browser/pages/login")

      const el: HTMLInputElement | null = document.querySelector("input#base")
      expect(el?.value).toBe("/hello-world")
    })
  })
  describe("there is not an element with id 'base'", () => {
    let spy: jest.SpyInstance

    beforeAll(() => {
      // This is important because we're manually requiring the file
      // If you don't call this before all tests
      // the module registry from other tests may cause side effects.
      jest.resetModuleRegistry()
    })

    beforeEach(() => {
      const dom = new JSDOM()
      global.document = dom.window.document
      spy = jest.spyOn(document, "getElementById")

      const location: LocationLike = {
        pathname: "/healthz",
        origin: "http://localhost:8080",
      }

      global.location = location as Location
    })

    afterEach(() => {
      spy.mockClear()
      jest.resetModules()
      // Reset the global.document
      global.document = undefined as any as Document
      global.location = undefined as any as Location
    })

    afterAll(() => {
      jest.restoreAllMocks()
    })

    it("should do nothing", () => {
      spy.mockImplementation(() => null)
      // Load file
      require("../../../../src/browser/pages/login")

      // It's called once by getOptions in the top of the file
      // and then another to get the base element
      expect(spy).toHaveBeenCalledTimes(2)
    })
  })
})