@golevelup/ts-sinon

Sinon Mocking (ts-sinon)

Utilities for making testing NestJS applications easier.

Getting Started

::: code-group

npm install @golevelup/ts-sinon -D

yarn add @golevelup/ts-sinon -D

pnpm add @golevelup/ts-sinon -D

:::

Creating Mocks

• Import the createMock function into your test class.
• Create a variable and set it equal to the createMock function with its generic type input.
• Use the mock, Luke.

Here's an example with NestJS' ExecutionContext:

import { createMock } from '@golevelup/ts-sinon';
import { ExecutionContext } from '@nestjs/common';

describe('Mocked Execution Context', () => {
  it('should have a fully mocked Execution Context', () => {
    const mockExecutionContext = createMock<ExecutionContext>();
    expect(mockExecutionContext.switchToHttp()).toBeDefined();
  });
});

createMock generates all sub-properties as sinon.stub(), so you can chain method calls:

it('should correctly resolve mocked providers', async () => {
  const request = {
    key: 'val',
  };

  mockExecutionContext.switchToHttp.returns(
    createMock<HttpArgumentsHost>({
      getRequest: () => request,
    }),
  );

  const mockResult = mockExecutionContext.switchToHttp().getRequest();
  expect(mockResult).toBe(request);
});

You can also easily provide your own mocks:

const mockExecutionContext = createMock<ExecutionContext>({
  switchToHttp: () => ({
    getRequest: () => ({
      headers: {
        authorization: 'auth',
      },
    }),
    getResponse: sinon.stub().returns({ data: 'res return data' }),
  }),
});

::: warning Note When providing your own mocks, the number of times a parent mock function was called includes the times needed to set your mocks. :::