index.test.js

const wait = require('./wait');
const process = require('process');
const cp = require('child_process');
const path = require('path');

test('throws invalid number', async() => {
    await expect(wait('foo')).rejects.toThrow('milleseconds not a number');
});

test('wait 500 ms', async() => {
    const start = new Date();
    await wait(500);
    const end = new Date();
    var delta = Math.abs(end - start);
    expect(delta).toBeGreaterThan(450);
});

// shows how the runner will run a javascript action with env / stdout protocol
test('test runs', () => {
    process.env['INPUT_MILLISECONDS'] = 500;
    const ip = path.join(__dirname, 'index.js');
    console.log(cp.execSync(`node ${ip}`, { env: process.env }).toString());
})