Perf tests

perf-tests.js

function performanceTests(...testCases) {
    const NUM_ITERATIONS = 5000000
    let results = []

    console.log(' -- Running tests... ')

    for (let i=0, l=testCases.length; i<l; i+=1) {
        results.push(testCases[i](NUM_ITERATIONS))
    }

    let slowest = results[0]
    let fastest = results[0]

    for (let result of results) {
        if (result.averageTime > slowest.averageTime)
            slowest = result
        if (result.averageTime < fastest.averageTime)
            fastest = result
    }

    console.log(' -- Done running tests. ')
    console.log(`   -- slowest: "${slowest.name}" -- `)
    console.log(`     - total time: ${slowest.totalTime}`)
    console.log(`     - average time: ${slowest.averageTime}`)
    console.log(`   -- fastest: "${fastest.name}" -- `)
    console.log(`     - total time: ${fastest.totalTime}`)
    console.log(`     - average time: ${fastest.averageTime}`)
}

//function testCase(name, setup, preTest, test, postTest, teardown) {
function testCase(name, {setup, preTest, test, postTest, teardown}) {
    return function(iterations) {
        if (!test) throw new Error('Um, you need a test.')

        const o = {}

        let totalTime = 0
        let averageTime
        let startTime
        let endTime

        console.log(`   -- Test "${name}" -- `)

        if (setup) setup(o)

        for (let i=0; i<iterations; i+=1) {
            if (preTest) preTest(o)

            startTime = performance.now()

            test(o)

            endTime = performance.now()
            totalTime += endTime - startTime

            if (postTest) postTest(o)
        }

        if (teardown) teardown(o)

        averageTime = totalTime/iterations

        console.log(`     - total time: ${totalTime}`)
        console.log(`     - average time: ${averageTime}`)

        return {name, totalTime, averageTime}
    }
}

performanceTests(
    testCase('with .has()', {
        setup(o) {
            o.s = new Set
            o.obj = {}
            o.s.add(o.obj)
        },
        test(o) {
            if (!o.s.has(o.obj))
                o.s.add(o.obj)
        },
    }),
    testCase('without .has()', {
        setup(o) {
            o.s = new Set
            o.obj = {}
            o.s.add(o.obj)
        },
        test(o) {
            o.s.add(o.obj)
        },
    })
)

performanceTests(
    testCase('with check', {
        setup(o) {
            o.f = window.f
            o.b = window.b
        },
        test(o) {
            if (o.f === o.b.parentNode) return
            o.f.appendChild(o.b)
        },
    }),
    testCase('without check', {
        setup(o) {
            o.f = window.f
            o.b = window.b
        },
        test(o) {
            o.f.appendChild(o.b)
        },
    })
)

performanceTests(
    testCase('with check', {
        setup() {
            document.body.style.display = 'none'
        },
        test() {
            if (document.body.style.display == 'none')
                document.body.style.display = 'block'
        },
    }),
    testCase('without check', {
        setup() {
            document.body.style.display = 'none'
        },
        test() {
            document.body.style.display = 'block'
        },
    })
)

performanceTests(
    testCase('with check', {
        setup() {
            document.body.style.display = 'none'
        },
        test() {
            if (document.body.style.display == 'none')
                document.body.style.display = 'block'
        },
    }),
    testCase('without check', {
        setup() {
            document.body.style.display = 'none'
        },
        test() {
            document.body.style.display = 'block'
        },
    })
)