karma-bench

A Karma plugin to run Benchmark.js v2

Based on karma-benchmark plugin, but it don't break tests functions context

Installation

npm install karma-bench --save-dev

Karma Configuration

Reporting results on the command line

To see jsPerf style results on the command line, install karma-benchmark-reporter:

npm install karma-benchmark-reporter --save-dev

Then, in karma.conf.js, add benchmark to the list of reporters:

module.exports = function(config) {
    config.set({
        // Other Karma config here...
        frameworks: ['bench'],
        reporters: ['benchmark']
    });
};

Run Karma:

karma start

Then, you'll then see output that looks like:

Chrome 51.0.2704 (Mac OS X 10.11.5)  Array iteration: util.each at 19356910 ops/sec
Chrome 51.0.2704 (Mac OS X 10.11.5)  Array iteration: Array.forEach at 2567531 ops/sec
Chrome 51.0.2704 (Mac OS X 10.11.5)  Array search: util.contains at 12635982 ops/sec
Chrome 51.0.2704 (Mac OS X 10.11.5)  Array search: Array.indexOf at 5828437 ops/sec
Chrome 51.0.2704 (Mac OS X 10.11.5)
  Array iteration: util.each at 19356910 ops/sec (7.54x faster than Array.forEach)
  Array search: util.contains at 12635982 ops/sec (2.17x faster than Array.indexOf)

Timeouts

As large suites of Benchmarks take a long time to run, you may need to increase Karma's timeout from it's default of 60000.

captureTimeout: 60000

Writing Benchmarks

Suites and benchmarks are defined using a wrapper for Benchmark.js in the form of the suite and benchmark globals.

Typical

In this example, a suite is defined that pits _.each against the native Array.forEach method:

suite('Array iteration', function() {
    benchmark('_.each', function() {
        _.each([1, 2, 3], function(el) {
            return el;
        });
    });
 
    benchmark('native forEach', function() {
        [1, 2, 3].forEach(function(el) {
            return el;
        });
    });
});

Suite options

Suite options are the same as in Benchmark.js.

See the Benchmark.js Suite constructor API docs for a full list of options.

suite('Array iteration', function() {
    benchmark('_.each', {
        fn: function () {
            _.each(this.list, function(number) {
                return number;
            });
        },
        setup: function() {
            this.list = [5, 4, 3];
        },
        teardown: function() {
            this.list = null;
        }
    });
}, {
    onCycle: function(event) {
        var suite = this;
        var benchmark = event.target;
        console.log('Cycle completed for ' + suite.name + ': ' + benchmark.name);
    }
});

Benchmark options

Benchmark options are the same as in Benchmark.js.

See the Benchmark.js Benchmark constructor API docs for a full list of options.