setTimeout(()=>{
    console.log('final final')
}, 3000)

/**
 * Effect: a promise is not returned, nor is a callback called
 * Findings: the outer setTimeout 'final final' runs to the end
 */
exports.emptiness = (event, context, callback) => {
    console.log('i do nothing')
}

/**
 * Effect: old school callback style
 * Findings: callback calls after sleep as expected
 */
exports.nonAsyncCallback = (event, context, callback) => {
    console.time('nonAsyncCallback')
    sleep(2)
    .then(()=>{
        console.timeEnd('nonAsyncCallback')
        callback(null, 'nonAsyncCallbackSuccess')
    })
};

/**
 * Effect: newschool promise style
 * Findings: promise resolves after sleep as expected
 */
exports.asyncStyle = async (event) => {
    console.time('asyncStyle')
    return sleep(2)
    .then(()=>{
        console.timeEnd('asyncStyle')
    })
}

/**
 * Effect: async function + use of callback
 * Findings: first one called back/resolved wins, outer 'final final' setTimeout never finishes
 *           should be fine if they both return the same thing,
 *           could be dodgy if callback has one thing and promise has another
 */
exports.asyncCallbackMadness = async (event, context, callback) => {
    console.time('asyncCallbackMadness')
    await sleep(2)


    console.timeEnd('asyncCallbackMadness')
    setTimeout(()=>{
      callback(null, 'asyncCallbackMadnessCallback')

    }, 0)
    return Promise.resolve('asyncCallbackMadnessPromise')
}

//shared helper
async function sleep(seconds) {
  return new Promise(resolve => setTimeout(resolve, seconds * 1000))
}