Jest Sandbox

A Sinon’s sandbox like for Jest Edit

Table of contents

• Setup
• API
• Examples

Setup

yarn add -D @jdes/jest-sandbox

API

spyOn(target: Object, property: string, create: ?boolean): Function

This method works like jest.spyOn with the only difference that
if the property to mocks does not exist and the parameters create is true, it will be created.

  const object = {};
  const spy = sandbox.spyOn(object, "add", true)
    .mockImplmentation((a, b) => a + b);
  expect(object.add(20, 22)).toBe(42);

restoreAllMocks(): void

Calls .mockRestore() on all spies in the sandbox.

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

Examples

import Sandbox from "@jdes/jest-sandbox"
describe("Readme's examples", () => {
  const sandbox = new Sandbox();
  afterEach(() => {
    sandbox.restoreAllMocks();
  });
  test("should calls API", () => {
    const service = {
      callApi: () => Promise.reject()
    };
    const spyLog = sandbox.spyOn(service, "log", true)
      .mockImplementation((log) => log);
    const spyCallApi = sandbox.spyOn(service, "callApi")
      .mockImplementation((path) => {
        service.log(`GET ${path}`);
        return Promise.resolve('Hello');
      });
    return service.callApi('/')
      .then((response) => {
        expect(spyCallApi).toHaveBeenCalled();
        expect(spyLog).toHaveBeenCalledWith('GET /');
        expect(response).toBe("Hello");
      });
  });
});