htmx/test/core/perf.js

describe("Core htmx perf Tests", function() {

    var HTMX_HISTORY_CACHE_NAME = "htmx-history-cache";

    beforeEach(function () {
        this.server = makeServer();
        clearWorkArea();
        localStorage.removeItem(HTMX_HISTORY_CACHE_NAME);
    });
    afterEach(function () {
        this.server.restore();
        clearWorkArea();
        localStorage.removeItem(HTMX_HISTORY_CACHE_NAME);
    });

    function stringRepeat(str, num) {
        num = Number(num);

        var result = '';
        while (true) {
            if (num & 1) { // (1)
                result += str;
            }
            num >>>= 1; // (2)
            if (num <= 0) break;
            str += str;
        }

        return result;
    }


    it("history implementation should be fast", function(){
        // create an entry with a large content string (256k) and see how fast we can write and read it
        // to local storage as a single entry
        var entry = {url: stringRepeat("x", 32), content:stringRepeat("x", 256*1024)}
        var array = [];
        for (var i = 0; i < 10; i++) {
            array.push(entry);
        }
        var start = performance.now();
        var string = JSON.stringify(array);
        localStorage.setItem(HTMX_HISTORY_CACHE_NAME, string);
        var reReadString = localStorage.getItem(HTMX_HISTORY_CACHE_NAME);
        var finalJson = JSON.parse(reReadString);
        var end = performance.now();
        var timeInMs = end - start;
        chai.assert(timeInMs < 300, "Should take less than 300ms on most platforms");
    })

    it("history snapshot cleaning should be fast", function(){
        var size = 5 * 1024 // ~350K in size, about the size of CNN's body tag :p
        if (IsIE11()) {
            // So slow in IE11 it freezes the browser and blocks other tests, pretty annoying
            size = 5 * 100 // Seriously this already takes ~1.5 SECOND to run, more simply makes it crash
        }
        var workArea = getWorkArea();
        var html = "<div class='foo bar'>Yay, really large HTML documents are fun!</div>\n";
        html = stringRepeat(html, size);
        workArea.insertAdjacentHTML("beforeend", html)
        var start = performance.now();
        htmx._("cleanInnerHtmlForHistory")(workArea);
        var end = performance.now();
        var timeInMs = end - start;
        chai.assert(timeInMs < 50, "Should take less than 50ms on most platforms");
    })

})