Sinon Mocking (ts-sinon)

Utilities for making testing NestJS applications easier.

Getting Started

::: code-group

``bash [npm]
npm install @golevelup/ts-sinon -D
`

`bash [yarn]
yarn add @golevelup/ts-sinon -D
`

`bash [pnpm]
pnpm add @golevelup/ts-sinon -D
`

:::

$3

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

Here's an example with NestJS' ExecutionContext:

`ts
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();
expect(mockExecutionContext.switchToHttp()).toBeDefined();
});
});
`

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

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

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

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

You can also easily provide your own mocks:

`ts
const mockExecutionContext = createMock({
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.
:::