Farenheith

import { MyClass } from './my-class';
export function getInstance() {
  return new MyClass(123);
}

Farenheith

import * as classToMock from '../src/my-class';
import { getInstance } from '../src/get-instance';
import { stub } from 'sinon';

describe('getInstance()', () => {
	const mockedInstance = {
		info: 'MyClass instance',
	};

	beforeEach(() => {

Farenheith

import { otherFunction } from './other-function';

export function myFunction() {
  return otherFunction(123);
}

Farenheith

import * as functionToMock from '../src/other-function';
import { myFunction } from '../src/my-function';
import { stub } from 'sinon';

describe('myFunction()', () => {
  beforeEach(() => {
    stub(functionToMock, 'otherFunction').returns('expected result' as any);
  });

  it('should return otherFunction result', () => {

Farenheith

if (process.env.IS_GOODBYE === 'true') {
  console.log('goodbye world!');
} else {
  console.log('hello world');
}

Farenheith

import { stub } from 'sinon';
import { expect } from 'chai';

describe('runnable.ts', () => {
  let target = '../src/runnable.ts';

  beforeEach(() => {
    stub(console, 'log');
  });

Farenheith

import untestableOldFunction = require('untestable-old-function');

export function doSomethingUntestable() {
  return untestableOldFunction(123);
}

Farenheith

import untestableOldFunction = require('untestable-old-function');

export const nowTestableOldFunction = untestableOldFunction as (p: number) => string;

Farenheith

import { expect } from 'chai';
import * as wrapper from '../src/untestable-wrapper';
import untestableOldFunction = require('untestable-old-function');

describe('untestable-wrapper', () => {
  it('should export untestableOldFunction as nowTestableOldFunction', () => {
    expect(wrapper.nowTestableOldFunction).to.be.eq(untestableOldFunction);
  });
});

Farenheith

import { nowTestableOldFunction } from './untestable-wrapper';

export function doSomethingUntestable() {
  return nowTestableOldFunction(123);
}