Benchmark.js ^v2.0.0

Benchmark(name, fn [, options={}])

# Ⓢ Ⓣ

The Benchmark constructor.

Note: The Benchmark constructor exposes a handful of lodash methods to make working with arrays, collections, and objects easier. The lodash methods are:
each/forEach, forOwn, has, indexOf, map, and reduce

Arguments

1. name (string): A name to identify the benchmark.
2. fn (Function|string): The test to benchmark.
3. [options={}] (Object): Options object.

Example

// basic usage (the `new` operator is optional)
var bench = new Benchmark(fn);

// or using a name first
var bench = new Benchmark('foo', fn);

// or with options
var bench = new Benchmark('foo', fn, {

  // displayed by `Benchmark#toString` if `name` is not available
  'id': 'xyz',

  // called when the benchmark starts running
  'onStart': onStart,

  // called after each run cycle
  'onCycle': onCycle,

  // called when aborted
  'onAbort': onAbort,

  // called when a test errors
  'onError': onError,

  // called when reset
  'onReset': onReset,

  // called when the benchmark completes running
  'onComplete': onComplete,

  // compiled/called before the test loop
  'setup': setup,

  // compiled/called after the test loop
  'teardown': teardown
});

// or name and options
var bench = new Benchmark('foo', {

  // a flag to indicate the benchmark is deferred
  'defer': true,

  // benchmark test function
  'fn': function(deferred) {
    // call `Deferred#resolve` when the deferred test is finished
    deferred.resolve();
  }
});

// or options only
var bench = new Benchmark({

  // benchmark name
  'name': 'foo',

  // benchmark test as a string
  'fn': '[1,2,3,4].sort()'
});

// a test’s `this` binding is set to the benchmark instance
var bench = new Benchmark('foo', function() {
  'My name is '.concat(this.name); // "My name is foo"
});

Benchmark.version

# Ⓢ Ⓣ

(string): The semantic version number.

Benchmark.filter(array, callback)

# Ⓢ Ⓣ

A generic Array#filter like method.

Arguments

1. array (Array): The array to iterate over.
2. callback (Function|string): The function/alias called per iteration.

Returns

(Array): A new array of values that passed callback filter.

Example

// get odd numbers
Benchmark.filter([1, 2, 3, 4, 5], function(n) {
  return n % 2;
}); // -> [1, 3, 5];

// get fastest benchmarks
Benchmark.filter(benches, 'fastest');

// get slowest benchmarks
Benchmark.filter(benches, 'slowest');

// get benchmarks that completed without erroring
Benchmark.filter(benches, 'successful');

Benchmark.formatNumber(number)

# Ⓢ Ⓣ

Converts a number to a more readable comma-separated string representation.

Arguments

1. number (number): The number to convert.

Returns

(string): The more readable string representation.

Benchmark.invoke(benches, name [, args])

# Ⓢ Ⓣ

Invokes a method on all items in an array.

Arguments

1. benches (Array): Array of benchmarks to iterate over.
2. name (Object|string): The name of the method to invoke OR options object.
3. [args] (…)*: Arguments to invoke the method with.

Returns

(Array): A new array of values returned from each method invoked.

Example

// invoke `reset` on all benchmarks
Benchmark.invoke(benches, 'reset');

// invoke `emit` with arguments
Benchmark.invoke(benches, 'emit', 'complete', listener);

// invoke `run(true)`, treat benchmarks as a queue, and register invoke callbacks
Benchmark.invoke(benches, {

  // invoke the `run` method
  'name': 'run',

  // pass a single argument
  'args': true,

  // treat as queue, removing benchmarks from front of `benches` until empty
  'queued': true,

  // called before any benchmarks have been invoked.
  'onStart': onStart,

  // called between invoking benchmarks
  'onCycle': onCycle,

  // called after all benchmarks have been invoked.
  'onComplete': onComplete
});

Benchmark.join(object [, separator1=',', separator2=': '])

# Ⓢ Ⓣ

Creates a string of joined array values or object key-value pairs.

Arguments

1. object (Array|Object): The object to operate on.
2. [separator1=','] (string): The separator used between key-value pairs.
3. [separator2=': '] (string): The separator used between keys and values.

Returns

(string): The joined result.

Benchmark.runInContext([context=root])

# Ⓢ Ⓣ

Create a new Benchmark function using the given context object.

Arguments

1. [context=root] (Object): The context object.

Returns

(Function): Returns a new Benchmark function.

Benchmark.prototype.aborted

# Ⓢ Ⓣ

(boolean): A flag to indicate if the benchmark is aborted.

Benchmark.prototype.compiled

# Ⓢ Ⓣ

(Function, string): The compiled test function.

Benchmark.prototype.count

# Ⓢ Ⓣ

(number): The number of times a test was executed.

Benchmark.prototype.cycles

# Ⓢ Ⓣ

(number): The number of cycles performed while benchmarking.

Benchmark.prototype.error

# Ⓢ Ⓣ

(Object): The error object if the test failed.

Benchmark.prototype.fn

# Ⓢ Ⓣ

(Function, string): The test to benchmark.

Benchmark.prototype.hz

# Ⓢ Ⓣ

(number): The number of executions per second.

Benchmark.prototype.running

# Ⓢ Ⓣ

(boolean): A flag to indicate if the benchmark is running.

Benchmark.prototype.setup

# Ⓢ Ⓣ

(Function, string): Compiled into the test and executed immediately before the test loop.

Example

// basic usage
var bench = Benchmark({
  'setup': function() {
    var c = this.count,
        element = document.getElementById('container');
    while (c--) {
      element.appendChild(document.createElement('div'));
    }
  },
  'fn': function() {
    element.removeChild(element.lastChild);
  }
});

// compiles to something like:
var c = this.count,
    element = document.getElementById('container');
while (c--) {
  element.appendChild(document.createElement('div'));
}
var start = new Date;
while (count--) {
  element.removeChild(element.lastChild);
}
var end = new Date - start;

// or using strings
var bench = Benchmark({
  'setup': '\
    var a = 0;\n\
    (function() {\n\
      (function() {\n\
        (function() {',
  'fn': 'a += 1;',
  'teardown': '\
         }())\n\
       }())\n\
     }())'
});

// compiles to something like:
var a = 0;
(function() {
  (function() {
    (function() {
      var start = new Date;
      while (count--) {
        a += 1;
      }
      var end = new Date - start;
    }())
  }())
}())

Benchmark.prototype.teardown

# Ⓢ Ⓣ

(Function, string): Compiled into the test and executed immediately after the test loop.

Benchmark.prototype.abort()

# Ⓢ Ⓣ

Aborts the benchmark without recording times.

Returns

(Object): The benchmark instance.

Benchmark.prototype.clone(options)

# Ⓢ Ⓣ

Creates a new benchmark using the same test and options.

Arguments

1. options (Object): Options object to overwrite cloned options.

Returns

(Object): The new benchmark instance.

Example

var bizarro = bench.clone({
  'name': 'doppelganger'
});

Benchmark.prototype.compare(other)

# Ⓢ Ⓣ

Determines if a benchmark is faster than another.

Arguments

1. other (Object): The benchmark to compare.

Returns

(number): Returns -1 if slower, 1 if faster, and 0 if indeterminate.

Benchmark.Suite.prototype.emit(type [, args])

# Ⓢ Ⓣ

Executes all registered listeners of the specified event type.

Arguments

1. type (Object|string): The event type or object.
2. [args] (…)*: Arguments to invoke the listener with.

Returns

()*: Returns the return value of the last listener executed.

Benchmark.Suite.prototype.listeners(type)

# Ⓢ Ⓣ

Returns an array of event listeners for a given type that can be manipulated to add or remove listeners.

Arguments

1. type (string): The event type.

Returns

(Array): The listeners array.

Benchmark.Suite.prototype.off([type, listener])

# Ⓢ Ⓣ

Unregisters a listener for the specified event type(s), or unregisters all listeners for the specified event type(s), or unregisters all listeners for all event types.

Arguments

1. [type] (string): The event type.
2. [listener] (Function): The function to unregister.

Returns

(Object): The benchmark instance.

Example

// unregister a listener for an event type
bench.off('cycle', listener);

// unregister a listener for multiple event types
bench.off('start cycle', listener);

// unregister all listeners for an event type
bench.off('cycle');

// unregister all listeners for multiple event types
bench.off('start cycle complete');

// unregister all listeners for all event types
bench.off();

Benchmark.Suite.prototype.on(type, listener)

# Ⓢ Ⓣ

Registers a listener for the specified event type(s).

Arguments

1. type (string): The event type.
2. listener (Function): The function to register.

Returns

(Object): The benchmark instance.

Example

// register a listener for an event type
bench.on('cycle', listener);

// register a listener for multiple event types
bench.on('start cycle', listener);

Benchmark.prototype.reset()

# Ⓢ Ⓣ

Reset properties and abort if running.

Returns

(Object): The benchmark instance.

Benchmark.prototype.run([options={}])

# Ⓢ Ⓣ

Runs the benchmark.

Arguments

1. [options={}] (Object): Options object.

Returns

(Object): The benchmark instance.

Example

// basic usage
bench.run();

// or with options
bench.run({ 'async': true });

Benchmark.prototype.toString()

# Ⓢ Ⓣ

Displays relevant benchmark information when coerced to a string.

Returns

(string): A string representation of the benchmark instance.

Benchmark.options

# Ⓢ Ⓣ

(Object): The default options copied by benchmark instances.

Benchmark.options.async

# Ⓢ Ⓣ

(boolean): A flag to indicate that benchmark cycles will execute asynchronously by default.

Benchmark.options.defer

# Ⓢ Ⓣ

(boolean): A flag to indicate that the benchmark clock is deferred.

Benchmark.options.delay

# Ⓢ Ⓣ

(number): The delay between test cycles (secs).

Benchmark.options.id

# Ⓢ Ⓣ

(string): Displayed by Benchmark#toString when a name is not available (auto-generated if absent).

Benchmark.options.initCount

# Ⓢ Ⓣ

(number): The default number of times to execute a test on a benchmark’s first cycle.

Benchmark.options.maxTime

# Ⓢ Ⓣ

(number): The maximum time a benchmark is allowed to run before finishing (secs).

Note: Cycle delays aren't counted toward the maximum time.

Benchmark.options.minSamples

# Ⓢ Ⓣ

(number): The minimum sample size required to perform statistical analysis.

Benchmark.options.minTime

# Ⓢ Ⓣ

(number): The time needed to reduce the percent uncertainty of measurement to 1% (secs).

Benchmark.options.name

# Ⓢ Ⓣ

(string): The name of the benchmark.

Benchmark.options.onAbort

# Ⓢ Ⓣ

An event listener called when the benchmark is aborted.

Benchmark.options.onComplete

# Ⓢ Ⓣ

An event listener called when the benchmark completes running.

Benchmark.options.onCycle

# Ⓢ Ⓣ

An event listener called after each run cycle.

Benchmark.options.onError

# Ⓢ Ⓣ

An event listener called when a test errors.

Benchmark.options.onReset

# Ⓢ Ⓣ

An event listener called when the benchmark is reset.

Benchmark.options.onStart

# Ⓢ Ⓣ

An event listener called when the benchmark starts running.

Benchmark.platform

# Ⓢ Ⓣ

(Object): Platform object with properties describing things like browser name, version, and operating system. See platform.js.

Benchmark.support

# Ⓢ Ⓣ

(Object): An object used to flag environments/features.

Benchmark.support.browser

# Ⓢ Ⓣ

(boolean): Detect if running in a browser environment.

Benchmark.support.decompilation

# Ⓢ Ⓣ

(boolean): Detect if function decompilation is support.

Benchmark.support.timeout

# Ⓢ Ⓣ

(boolean): Detect if the Timers API exists.

Benchmark.prototype.stats

# Ⓢ Ⓣ

(Object): An object of stats including mean, margin or error, and standard deviation.

Benchmark.prototype.stats.deviation

# Ⓢ Ⓣ

(number): The sample standard deviation.

Benchmark.prototype.stats.mean

# Ⓢ Ⓣ

(number): The sample arithmetic mean (secs).

Benchmark.prototype.stats.moe

# Ⓢ Ⓣ

(number): The margin of error.

Benchmark.prototype.stats.rme

# Ⓢ Ⓣ

(number): The relative margin of error (expressed as a percentage of the mean).

Benchmark.prototype.stats.sample

# Ⓢ Ⓣ

(Array): The array of sampled periods.

Benchmark.prototype.stats.sem

# Ⓢ Ⓣ

(number): The standard error of the mean.

Benchmark.prototype.stats.variance

# Ⓢ Ⓣ

(number): The sample variance.

Benchmark.prototype.times

# Ⓢ Ⓣ

(Object): An object of timing data including cycle, elapsed, period, start, and stop.

Benchmark.prototype.times.cycle

# Ⓢ Ⓣ

(number): The time taken to complete the last cycle (secs).

Benchmark.prototype.times.elapsed

# Ⓢ Ⓣ

(number): The time taken to complete the benchmark (secs).

Benchmark.prototype.times.period

# Ⓢ Ⓣ

(number): The time taken to execute the test once (secs).

Benchmark.prototype.times.timeStamp

# Ⓢ Ⓣ

(number): A timestamp of when the benchmark started (ms).

Benchmark.Deferred(clone)

# Ⓢ Ⓣ

The Deferred constructor.

Arguments

1. clone (Object): The cloned benchmark instance.

Benchmark.Deferred.prototype.benchmark

# Ⓢ Ⓣ

(Object): The deferred benchmark instance.

Benchmark.Deferred.prototype.cycles

# Ⓢ Ⓣ

(number): The number of deferred cycles performed while benchmarking.

Benchmark.Deferred.prototype.elapsed

# Ⓢ Ⓣ

(number): The time taken to complete the deferred benchmark (secs).

Benchmark.Deferred.prototype.timeStamp

# Ⓢ Ⓣ

(number): A timestamp of when the deferred benchmark started (ms).

Benchmark.Event(type)

# Ⓢ Ⓣ

The Event constructor.

Arguments

1. type (Object|string): The event type.

Benchmark.Event.prototype.aborted

# Ⓢ Ⓣ

(boolean): A flag to indicate if the emitters listener iteration is aborted.

Benchmark.Event.prototype.cancelled

# Ⓢ Ⓣ

(boolean): A flag to indicate if the default action is cancelled.

Benchmark.Event.prototype.currentTarget

# Ⓢ Ⓣ

(Object): The object whose listeners are currently being processed.

Benchmark.Event.prototype.result

# Ⓢ Ⓣ

(Mixed): The return value of the last executed listener.

Benchmark.Event.prototype.target

# Ⓢ Ⓣ

(Object): The object to which the event was originally emitted.

Benchmark.Event.prototype.timeStamp

# Ⓢ Ⓣ

(number): A timestamp of when the event was created (ms).

Benchmark.Event.prototype.type

# Ⓢ Ⓣ

(string): The event type.

Benchmark.Suite(name [, options={}])

# Ⓢ Ⓣ

The Suite constructor.

Note: Each Suite instance has a handful of wrapped lodash methods to make working with Suites easier. The wrapped lodash methods are:
each/forEach, indexOf, map, and reduce

Arguments

1. name (string): A name to identify the suite.
2. [options={}] (Object): Options object.

Example

// basic usage (the `new` operator is optional)
var suite = new Benchmark.Suite;

// or using a name first
var suite = new Benchmark.Suite('foo');

// or with options
var suite = new Benchmark.Suite('foo', {

  // called when the suite starts running
  'onStart': onStart,

  // called between running benchmarks
  'onCycle': onCycle,

  // called when aborted
  'onAbort': onAbort,

  // called when a test errors
  'onError': onError,

  // called when reset
  'onReset': onReset,

  // called when the suite completes running
  'onComplete': onComplete
});

Benchmark.Suite.prototype.aborted

# Ⓢ Ⓣ

(boolean): A flag to indicate if the suite is aborted.

Benchmark.Suite.prototype.length

# Ⓢ Ⓣ

(number): The number of benchmarks in the suite.

Benchmark.Suite.prototype.running

# Ⓢ Ⓣ

(boolean): A flag to indicate if the suite is running.

Benchmark.Suite.prototype.abort()

# Ⓢ Ⓣ

Aborts all benchmarks in the suite.

Returns

(Object): The suite instance.

Benchmark.Suite.prototype.add(name, fn [, options={}])

# Ⓢ Ⓣ

Adds a test to the benchmark suite.

Arguments

1. name (string): A name to identify the benchmark.
2. fn (Function|string): The test to benchmark.
3. [options={}] (Object): Options object.

Returns

(Object): The benchmark instance.

Example

// basic usage
suite.add(fn);

// or using a name first
suite.add('foo', fn);

// or with options
suite.add('foo', fn, {
  'onCycle': onCycle,
  'onComplete': onComplete
});

// or name and options
suite.add('foo', {
  'fn': fn,
  'onCycle': onCycle,
  'onComplete': onComplete
});

// or options only
suite.add({
  'name': 'foo',
  'fn': fn,
  'onCycle': onCycle,
  'onComplete': onComplete
});

Benchmark.Suite.prototype.clone(options)

# Ⓢ Ⓣ

Creates a new suite with cloned benchmarks.

Arguments

1. options (Object): Options object to overwrite cloned options.

Returns

(Object): The new suite instance.

Benchmark.Suite.prototype.emit(type [, args])

# Ⓢ Ⓣ

Executes all registered listeners of the specified event type.

Arguments

1. type (Object|string): The event type or object.
2. [args] (…)*: Arguments to invoke the listener with.

Returns

()*: Returns the return value of the last listener executed.

Benchmark.Suite.prototype.filter(callback)

# Ⓢ Ⓣ

An Array#filter like method.

Arguments

1. callback (Function|string): The function/alias called per iteration.

Returns

(Object): A new suite of benchmarks that passed callback filter.

Benchmark.Suite.prototype.listeners(type)

# Ⓢ Ⓣ

Returns an array of event listeners for a given type that can be manipulated to add or remove listeners.

Arguments

1. type (string): The event type.

Returns

(Array): The listeners array.

Benchmark.Suite.prototype.off([type, listener])

# Ⓢ Ⓣ

Unregisters a listener for the specified event type(s), or unregisters all listeners for the specified event type(s), or unregisters all listeners for all event types.

Arguments

1. [type] (string): The event type.
2. [listener] (Function): The function to unregister.

Returns

(Object): The benchmark instance.

Example

// unregister a listener for an event type
bench.off('cycle', listener);

// unregister a listener for multiple event types
bench.off('start cycle', listener);

// unregister all listeners for an event type
bench.off('cycle');

// unregister all listeners for multiple event types
bench.off('start cycle complete');

// unregister all listeners for all event types
bench.off();

Benchmark.Suite.prototype.on(type, listener)

# Ⓢ Ⓣ

Registers a listener for the specified event type(s).

Arguments

1. type (string): The event type.
2. listener (Function): The function to register.

Returns

(Object): The benchmark instance.

Example

// register a listener for an event type
bench.on('cycle', listener);

// register a listener for multiple event types
bench.on('start cycle', listener);

Benchmark.Suite.prototype.reset()

# Ⓢ Ⓣ

Resets all benchmarks in the suite.

Returns

(Object): The suite instance.

Benchmark.Suite.prototype.run([options={}])

# Ⓢ Ⓣ

Runs the suite.

Arguments

1. [options={}] (Object): Options object.

Returns

(Object): The suite instance.

Example

// basic usage
suite.run();

// or with options
suite.run({ 'async': true, 'queued': true });

Benchmark.Suite.options

# Ⓢ Ⓣ

(Object): The default options copied by suite instances.

Benchmark.Suite.options.name

# Ⓢ Ⓣ

(string): The name of the suite.