Simple test for example-stream.ts

example-stream.spec.ts

import { expect } from 'chai';
import { stub } from 'sinon';
import * as zlib from 'zlib';
import { streamExample } from '../src/stream-example';

describe.only('streamExample()', () => {
	beforeEach(() => {
		stub(zlib, 'createGzip').returns('createGZip result' as any);
	});

	it('should pipe the given stream to a gzip writer', async () => {
		const stream = {
			pipe: stub().returns('piped stream' as any),
		};

		const result = streamExample(stream as any);

		expect(zlib.createGzip).to.have.been.calledOnceWithExactly();
		expect(stream.pipe).to.have.been.calledOnceWithExactly('createGZip result');
		expect(result).to.be.eq('piped stream');
	});
})