empower

Power Assert feature enhancer for assert function/object.

DESCRIPTION

empower is a core module of power-assert family. empower enhances standard assert function or any assert-like object to work with power-assert feature added code instrumented by espower.

empower works with standard assert function (best fit with Mocha), and also supports assert-like objects/functions provided by various testing frameworks such as QUnit, buster.js, and nodeunit.

Pull-requests, issue reports and patches are always welcomed. See power-assert project for more documentation.

CHANGELOG

See CHANGELOG

API

var enhancedAssert = empower(originalAssert, formatter, [options])

empower function takes function or object(originalAssert) and formatter function created by power-assert-formatter then returns PowerAssert feature added function/object base on originalAssert. If destructive option is falsy, originalAssert will be unchanged. If destructive option is truthy, originalAssert will be manipulated directly and returned enhancedAssert will be the same instance of originalAssert.

originalAssert

originalAssert is an instance of standard assert function or any assert-like object. see SUPPORTED ASSERTION LIBRARIES and ASSERTION LIBRARIES KNOWN TO WORK section. Be careful that originalAssert will be manipulated directly if destructive option is truthy.

formatter

formatter function created by power-assert-formatter.

options

Configuration options. If not passed, default options will be used.

options.destructive

If truthy, modify originalAssert destructively.

If false, empower mimics originalAssert as new object/function, so originalAssert will not be changed. If true, originalAssert will be manipulated directly and returned enhancedAssert will be the same instance of originalAssert.

options.modifyMessageOnRethrow

If truthy, modify message property of AssertionError on rethrow.

options.saveContextOnRethrow

If truthy, add powerAssertContext property to AssertionError on rethrow.

modifyMessageOnRethrow option and saveContextOnRethrow option makes behavior matrix as below.

options.patterns

[
    'assert(value, [message])',
    'assert.ok(value, [message])',
    'assert.equal(actual, expected, [message])',
    'assert.notEqual(actual, expected, [message])',
    'assert.strictEqual(actual, expected, [message])',
    'assert.notStrictEqual(actual, expected, [message])',
    'assert.deepEqual(actual, expected, [message])',
    'assert.notDeepEqual(actual, expected, [message])',
    'assert.deepStrictEqual(actual, expected, [message])',
    'assert.notDeepStrictEqual(actual, expected, [message])'
]

Target patterns for power assert feature instrumentation.

Pattern detection is done by escallmatch. Any arguments enclosed in bracket (for example, [message]) means optional parameters. Without bracket means mandatory parameters.

var options = empower.defaultOptions();

Returns default options object for empower function. In other words, returns

{
    destructive: false,
    modifyMessageOnRethrow: false,
    saveContextOnRethrow: false,
    patterns: [
        'assert(value, [message])',
        'assert.ok(value, [message])',
        'assert.equal(actual, expected, [message])',
        'assert.notEqual(actual, expected, [message])',
        'assert.strictEqual(actual, expected, [message])',
        'assert.notStrictEqual(actual, expected, [message])',
        'assert.deepEqual(actual, expected, [message])',
        'assert.notDeepEqual(actual, expected, [message])',
        'assert.deepStrictEqual(actual, expected, [message])',
        'assert.notDeepStrictEqual(actual, expected, [message])'
    ]
}

SUPPORTED ASSERTION LIBRARIES

• Node assert API
• Jxck/assert

ASSERTION LIBRARIES KNOWN TO WORK

• QUnit.assert
• nodeunit
• buster-assertions

INSTALL

via npm

Install

$ npm install --save-dev empower

use empower npm module on browser

empower function is exported

<script type="text/javascript" src="./path/to/node_modules/empower/build/empower.js"></script>

via bower

Install

$ bower install --save-dev empower

Then load (empower function is exported)

<script type="text/javascript" src="./path/to/bower_components/empower/build/empower.js"></script>

OUR SUPPORT POLICY

We support Node under maintenance. In other words, we stop supporting old Node version when their maintenance ends.

We also support "modern enough" browsers such as Chrome, Firefox, Safari, Edge etc.

Any other environments are not supported officially (means that we do not test against them on CI service). empower is known to work with old browsers, and trying to keep them working though.

AUTHOR

• Takuto Wada

CONTRIBUTORS

• James Talmage (jamestalmage)

LICENSE

Licensed under the MIT license.