npm package discovery and stats viewer.

Discover Tips

  • General search

    [free text search, go nuts!]

  • Package details

    pkg:[package-name]

  • User packages

    @[username]

Sponsor

Optimize Toolset

I’ve always been into building performant and accessible sites, but lately I’ve been taking it extremely seriously. So much so that I’ve been building a tool to help me optimize and monitor the sites that I build to make sure that I’m making an attempt to offer the best experience to those who visit them. If you’re into performant, accessible and SEO friendly sites, you might like it too! You can check it out at Optimize Toolset.

About

Hi, 👋, I’m Ryan Hefner  and I built this site for me, and you! The goal of this site was to provide an easy way for me to check the stats on my npm packages, both for prioritizing issues and updates, and to give me a little kick in the pants to keep up on stuff.

As I was building it, I realized that I was actually using the tool to build the tool, and figured I might as well put this out there and hopefully others will find it to be a fast and useful way to search and browse npm packages as I have.

If you’re interested in other things I’m working on, follow me on Twitter or check out the open source projects I’ve been publishing on GitHub.

I am also working on a Twitter bot for this site to tweet the most popular, newest, random packages from npm. Please follow that account now and it will start sending out packages soon–ish.

Open Software & Tools

This site wouldn’t be possible without the immense generosity and tireless efforts from the people who make contributions to the world and share their work via open source initiatives. Thank you 🙏

© 2024 – Pkg Stats / Ryan Hefner

rebenchmark

v2.0.0

Published

Benchmark.js runner for Node.js and browsers with BDD interface (like Mocha).

Downloads

7

Readme

rebenchmark

npm

Benchmark.js runner for Node.js and browsers with BDD interface (like Mocha).

Online Playground

Based on @venkatperi's bench-runner.

Table of contents

Getting Started

Install with npm:

npm install rebenchmark -g
mkdir benchmarks
$EDITOR benchmarks/string.js # open with your favorite editor

In your editor:

suite('find in string', () => {
    bench('RegExp#test', () => /o/.test('Hello World!'));
    bench('String#indexOf', () => 'Hello World!'.indexOf('o') > -1);
    bench('String#match', () => !!'Hello World!'.match(/o/));
});

Back in the terminal:

$ rebenchmark

[find in string]
  RegExp#test x 37,304,988 ops/sec ±1.81% (88 runs sampled)
  String#indexOf x 873,212,283 ops/sec ±1.68% (89 runs sampled)
  String#match x 17,030,626 ops/sec ±1.25% (85 runs sampled)

For elder versions of node (< 12), use rebenchmark-cjs command instead.

Suites & Benchmarks

Group benchmarks in a suite:

suite('group-of-tests', () => {
    bench('a-benchmark', ...);
    bench('yet-a-benchmark', ...);
});

Paths

Suites and benchmarks are assigned paths which are useful, for example, for filtering with the grep option. Paths are constructed by concatenating the names of suites and benchmarks leading to the target, separated with a colon :. In the above snippet, benchmark a-benchmark has the path :group-of-tests:a-benchmark.

Nested Suites & Benchmarks

Suites can be nested:

suite('es5 vs es6', () => {
    suite('classes', () => {
        function ES5() { this.foo = 'bar'; }
        ES5.prototype.bar = function () { };

        class ES6 {
            constructor() { this.foo = 'bar'; }
            bar() { }
        }

        bench('es5', () => new ES5());
        bench('es6', () => new ES6());
    });

    suite('arrow functions', () => {
        const es5obj = {
            value: 42,
            fn() { return function () { return es5obj.value; }; }
        };
        const es5fn = es5obj.fn();

        const es6obj = {
            value: 42,
            fn() { return () => this.value; }
        };
        const es6fn = es6obj.fn();

        bench('es5', es5fn);
        bench('es6', es6fn);
    });
});

Output:

$ rebenchmark

[es5 vs es6]
  [arrow functions]
    es5 x 957,326,571 ops/sec ±1.53% (94 runs sampled)
    es6 x 957,566,235 ops/sec ±1.40% (93 runs sampled)
  [classes]
    es5 x 932,924,301 ops/sec ±1.26% (92 runs sampled)
    es6 x 896,497,968 ops/sec ±2.84% (91 runs sampled)
  [generator]
    es5 x 15,930,495 ops/sec ±1.70% (89 runs sampled)
    es6 x 16,374,339 ops/sec ±1.90% (89 runs sampled)

Benchmarking Asynchronous Functions

To defer a benchmark, pass an callback argument to the benchmark function. The callback must be called to end the benchmark.

suite('deferred', () => {
    bench('timeout', (done) => setTimeout(done, 100));
});

Output:

[deferred]
  timeout x 9.72 ops/sec ±0.41% (49 runs sampled)

Dynamically Generating Benchmarks

Use javascript to generate benchmarks or suites dynamically:

suite('buffer allocation', () => {
    for (let size = minSize; size <= maxSize; size *= 2) {
        bench(size, () => Buffer.allocUnsafe(size));
    }
})

The above code will produce a suite with multiple benchmarks:

[buffer allocation]
  1024 x 2,958,389 ops/sec ±2.85% (81 runs sampled)
  2048 x 1,138,591 ops/sec ±2.42% (52 runs sampled)
  4096 x 462,223 ops/sec ±2.48% (54 runs sampled)
  8192 x 324,956 ops/sec ±1.56% (44 runs sampled)
  16384 x 199,686 ops/sec ±0.94% (80 runs sampled)

Exclusive & Inclusive Benchmarks

The exclusivity feature allows you to run only the specified suite or benchmark by appending .only() to the function. Here’s an example of executing only a particular suite:

suite('es5 vs es6', () => {
    suite.only('arrow functions', () => {
        const es5obj = {
            value: 42,
            fn() { return function () { return es5obj.value; }; }
        };
        const es5fn = es5obj.fn();

        const es6obj = {
            value: 42,
            fn() { return () => this.value; }
        };
        const es6fn = es6obj.fn();

        bench('es5', es5fn);
        bench('es6', es6fn);
    });

    suite('classes', () => {
        function ES5() { this.foo = 'bar'; }

        ES5.prototype.bar = function () { };

        class ES6 {
            constructor() { this.foo = 'bar'; }

            bar() { }
        }

        bench('es5', () => new ES5());
        bench('es6', () => new ES6());
    });
});

Only arrow functions suite will be run.

The inclusitiy feature is the inverse of .only(). By appending .skip(), you may tell runner to ignore test case(s). Here’s an example of skipping an individual test:

suite('es5 vs es6', () => {
    suite.skip('arrow functions', () => {
        const es5obj = {
            value: 42,
            fn() { return function () { return es5obj.value; }; }
        };
        const es5fn = es5obj.fn();

        const es6obj = {
            value: 42,
            fn() { return () => this.value; }
        };
        const es6fn = es6obj.fn();

        bench('es5', es5fn);
        bench('es6', es6fn);
    });

    suite('classes', () => {
        function ES5() { this.foo = 'bar'; }

        ES5.prototype.bar = function () { };

        class ES6 {
            constructor() { this.foo = 'bar'; }

            bar() { }
        }

        bench('es5', () => new ES5());
        bench('es6', () => new ES6());
    });
});

arrow functions suite will be skipped.

Usage

CLI

rebenchmark [options] <benchmarks..>

Options:
  --include, -i           File pattern(s) to include                     [array]
  --exclude, -x           File pattern(s) to exclude                     [array]
  --grep, -g              Run only tests matching pattern(s)             [array]
  --dry, -d               Do a dry run without executing benchmarks    [boolean]
  --reporter, -R          Specify which reporter to use
                                                   [string] [default: "console"]
  --reporter-options, -O  Reporter-specific options (<k1=v1[,k2=v2,..]>) [array]
  --platform, -p          Print platform information                   [boolean]
  --delay                 The delay between test cycles (secs)          [number]
  --init-count            The default number of times to execute a test on a
                          benchmark’s first cycle                       [number]
  --max-time              The maximum time a benchmark is allowed to run before
                          finishing (secs)                              [number]
  --min-samples           The minimum sample size required to perform
                          statistical analysis                          [number]
  --min-time              The time needed to reduce the percent uncertainty of
                          measurement to 1% (secs)                      [number]
  --config, -c            Path to JSON config file
  --help, -h              Show help                                    [boolean]
  --version, -v           Show version number                          [boolean]

By default, rebenchmark looks for *.js files under the benchmarks/ subdirectory only. To configure where rebenchmark looks for tests, you may pass your own glob:

rebenchmark 'benches/**/*.{js,mjs}'

-i, --include=<regex>

Run benchmarks files with paths match the given regex, e.g.:

rebenchmark -i string

-x, --exclude=<regex>

Skip benchmarks files with paths match the given regex, e.g.:

rebenchmark -x deferred

-g, --grep=<regex>

The --grep option will trigger runner to only run tests whose paths match the given regex.

In the snippet below:

  • rebenchmark -g es5 will match only :compare:classes:es5 and :compare:arrow functions:es5
  • rebenchmark -g arrow will match :compare:arrow functions:es5 and :compare:arrow functions:es6
suite('compare', () => {
    suite('classes', () => {
        bench('es5', () => new ES5());
        bench('es6', () => new ES6());
    });

    suite('arrow functions', () => {
        bench('es5', es5fn);
        bench('es6', es6fn);
    });
});

-d, --dry

Enables dry-run mode which cycles through the suites and benchmarks selected by other settings such as grep without actually executing the benchmark code. This mode can be useful to verify the selection by a particular grep filter.

-R, --reporter=<name|url>

The --reporter option allows you to specify the reporter that will be used. Could be the name of one of the predefined printers (see reporters section), or the url of the module with default exported class that will be used as reporter.

-O, --reporter-options=<k1=v1[,k2=v2,..]>

Reporter-specific options, e.g.:

rebenchmark -O indent=4,results,format=full

--delay, --init-count, --max-time, --min-samples, --min-time

These options are passed directly to benchmark.js.

-c, --config=<path>

You can save frequently used sets of options to the JSON file and use it when starting the runner:

rebenchmark -c rebenchmark.config.json

rebenchmark.config.json:

{
    "benchmarks": [
        "benches/**/*.js"
    ],
    "platform": true,
    "reporter": "console",
    "reporterOptions": {
        "indent": 4,
        "results": "true",
        "format": "full"
    }
}

Node.js

import { suite, bench, run, resetOptions, reporters } from 'rebenchmark';

resetOptions({
    reporter: new reporters.ConsoleReporter({ indent: 4 }),
    platform: true,
    filter: 'fastest'
});

suite('find in string', () => {
    bench('RegExp#test', () => /o/.test('Hello World!'));
    bench('String#indexOf', () => 'Hello World!'.indexOf('o') > -1);
    bench('String#match', () => !!'Hello World!'.match(/o/));
});

run().then(() => {
    console.log('All done!');
});

Browsers

Automatic setup:

<!DOCTYPE html>
<html>

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Rebenchmark</title>
    <!-- Benchmark.js dependencies are not included, therefore must be provided manually -->
    <script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.15/lodash.min.js"></script>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/platform/1.3.5/platform.min.js"></script>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/benchmark/2.1.4/benchmark.min.js"></script>
</head>

<body>
    <!-- The output is printed to the element with the identifier 'rebenchmark', if any, and duplicated to the console -->
    <pre id="rebenchmark"></pre>

    <!-- Options can be passed using data-attributes -->
    <script src="https://unpkg.com/rebenchmark/stage/browser/rebenchmark.min.js" data-platform="true"></script>
    <!-- Include this script to automatic setup -->
    <script src="https://unpkg.com/rebenchmark/stage/browser/rebenchmark-autosetup.min.js"></script>
    <!-- Suites can be specified with files -->
    <script src="benchmarks/es5_vs_es6.js"></script>
    <!-- Or be the inline scripts -->
    <script>
        suite('find in string', () => {
            bench('RegExp#test', () => /o/.test('Hello World!'));
            bench('String#indexOf', () => 'Hello World!'.indexOf('o') > -1);
            bench('String#match', () => !!'Hello World!'.match(/o/));
        });
    </script>
</body>

</html>

Manual setup:

<!DOCTYPE html>
<html>

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Rebenchmark</title>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.15/lodash.min.js"></script>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/platform/1.3.5/platform.min.js"></script>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/benchmark/2.1.4/benchmark.min.js"></script>
</head>

<body>
    <pre id="rebenchmark"></pre>

    <!-- To disable automatic setup, set "data-no-auto-setup" to "true" -->
    <script src="https://unpkg.com/rebenchmark/stage/browser/rebenchmark.min.js"></script>
    <script>
        rebenchmark.setup({
            reporter: new rebenchmark.reporters.HTMLReporter({
                root: document.querySelector('#rebenchmark'),
                results: true
            }),
            platform: true
        });
    </script>
    <script src="benchmarks/es5_vs_es6.js"></script>
    <script>
        suite('find in string', () => {
            bench('RegExp#test', () => /o/.test('Hello World!'));
            bench('String#indexOf', () => 'Hello World!'.indexOf('o') > -1);
            bench('String#match', () => !!'Hello World!'.match(/o/));
        });
    </script>
    <script>
        rebenchmark.run().then(() => {
            console.log('All done!');
        });
    </script>
</body>

</html>

Legacy browsers support

At the moment, the main entry point is compiling using ES6+. If you need support for older browsers, use rebenchmark-legacy.js or rebenchmark-legacy.min.js, e.g.:

<script src="https://unpkg.com/rebenchmark/stage/browser/rebenchmark-legacy.min.js"></script>

TypeScript

You can write and run benchmarks with TypeScript.

/// <reference types="rebenchmark" />
suite('forLoop', () => {
    function forEach<T>(array: ArrayLike<T>, callbackfn: (value: T, index: number, array: ArrayLike<T>) => void, thisArg?: any) {
        for (let i = 0; i < array.length; i++)
            callbackfn.call(thisArg, array[i], i, array);
    }

    [
        ['empty array', []],
        ['small array', new Array(10).fill(1)],
        ['medium array', new Array(100).fill(1)],
        ['large array', new Array(10000).fill(1)]
    ].forEach(([title, array]: [string, number[]]) => {
        suite(title, () => {
            bench('conventional for', () => {
                let sum = 0;
                for (let i = 0; i < array.length; i++) {
                    const value = array[i];
                    sum += value;
                    sum += i;
                    sum += value;
                }
                return sum;
            });

            bench('for of', () => {
                let sum = 0;
                let i = 0;
                for (const value of array) {
                    sum += value;
                    sum += i;
                    sum += value;
                    i++;
                }
                return sum;
            });

            bench('forEach', () => {
                let sum = 0;
                array.forEach((value, i) => {
                    sum += value;
                    sum += i;
                    sum += value
                });
                return sum;
            });

            bench('self-made forEach', () => {
                let sum = 0;
                forEach(array, (value, i) => {
                    sum += value;
                    sum += i;
                    sum += value
                });
                return sum;
            });
        });
    });
});

If you don't like triple-slash directives, you can specify types with types compiler option:

{
    "compilerOptions": {
        "types": [
            "rebenchmark"
        ]
    }
}

To run benchmarks, install ts-node, then use following commands.

With ESM modules:

node --loader ts-node/esm ./node_modules/rebenchmark/module/node/entry.js -- ./benchmarks/*.ts

With CJS modules:

node --require ts-node/register ./node_modules/rebenchmark/commonjs/node/entry.js -- ./benchmarks/*.ts

It is handy to save this command in the package.json's script section, e.g.

{
    "scripts": {
        "ts-bench": "node --loader ts-node/esm ./node_modules/rebenchmark/module/node/entry.js"
    }
}

Hooks

Hooks must be synchronous since they are called by benchmark.js which does not support async hooks at this time. Also, setup and teardown are compiled into the test function. Including either may place restrictions on the scoping/availability of variables in the test function (see benchmark.js docs for more information).

suite('hooks', () => {
    before(() => {
        // runs before all tests in this suite
    });

    after(() => {
        // runs after all tests in this suite
    });

    beforeEach(() => {
        // runs before each benchmark test function in this suite
    });

    afterEach(() => {
        // runs after each benchmark test function in this suite
    });

    bench('name', {
        setup() {
            // setup is compiled into the test function and runs before each cycle of the test
        }
    })

    bench('name', {
        teardown() {
            // teardown is compiled into the test function and runs after each cycle of the test
        }
    }, testFn)

    // benchmarks here...
});

Reporters

console

The default reporter. Pretty prints results via console.log.

Options:

  • indent - number of spaces used to insert white space into the output for readability purposes
  • results - print benchmark results (boolean).

You can specify format option when results option is set, choices: full, short (default).

Examples:

rebenchmark -O results
[find in string]
  RegExp#test x 39,657,648 ops/sec ±2.77% (83 runs sampled)
  String#indexOf x 916,877,868 ops/sec ±1.76% (90 runs sampled)
  String#match x 21,233,309 ops/sec ±2.18% (89 runs sampled)
┌────────────────┬────────────────┐
│    (bench)     │ find in string │
├────────────────┼────────────────┤
│  RegExp#test   │   96% slower   │
│ String#indexOf │    fastest     │
│  String#match  │   98% slower   │
└────────────────┴────────────────┘

rebenchmark -O results,format=full
[find in string]
  RegExp#test x 38,496,031 ops/sec ±4.35% (85 runs sampled)
  String#indexOf x 890,481,584 ops/sec ±1.74% (89 runs sampled)
  String#match x 19,204,268 ops/sec ±2.12% (83 runs sampled)
┌────────────────┬─────────────────────┐
│                │                     │
│    (bench)     │   find in string    │
│                │                     │
├────────────────┼─────────────────────┤
│                │ 38,496,031 ops/sec  │
│  RegExp#test   │       ±4.35%        │
│                │     96% slower      │
├────────────────┼─────────────────────┤
│                │ 890,481,584 ops/sec │
│ String#indexOf │       ±1.74%        │
│                │       fastest       │
├────────────────┼─────────────────────┤
│                │ 19,204,268 ops/sec  │
│  String#match  │       ±2.12%        │
│                │     98% slower      │
└────────────────┴─────────────────────┘

json

Outputs a single large JSON object when the tests have completed.

Options:

  • indent - number of spaces used to insert white space into the output for readability purposes.

html

Prints results into HTML element. Intended for use only on browsers.

Options:

  • root - CSS-selector or HTML-element by itself where to print results
  • echo - whether to duplicate output to console (true by default)

And all options inherited from console reporter.

null

Discards all output.