11 KiB
empower-core
Power Assert feature enhancer for assert function/object.
DESCRIPTION
empower-core
is a core module of power-assert family. empower-core
enhances standard assert
function or any assert-like object to work with power-assert feature added code instrumented by espower.
empower-core
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 = empowerCore(originalAssert, [options])
return type |
---|
function or object |
empower-core
function takes function or object(originalAssert
) then returns PowerAssert feature added function/object based 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
type | default value |
---|---|
function or object |
N/A |
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.
options
type | default value |
---|---|
object |
(return value of empowerCore.defaultOptions() ) |
Configuration options. If not passed, default options will be used.
options.destructive
type | default value |
---|---|
boolean |
false |
If truthy, modify originalAssert
destructively.
If false
, empower-core 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.bindReceiver
type | default value |
---|---|
boolean |
true |
bindReceiver
defaults to true
, meaning assertion methods have their this
value bound to the original assertion. Setting bindReceiver
to false causes the this
reference to be passed through from the actual invocation.
options.onError
options.onSuccess
type | default value |
---|---|
function |
(function defined in empowerCore.defaultOptions() ) |
Both methods are called with a single event
argument, it will have the following properties:
-
event.enhanced
-true
for methods matchingpatterns
.false
for methods matchingwrapOnlyPatterns
. -
event.originalMessage
- The actual value the user provided for optionalmessage
parameter. This will beundefined
if the user did not provide a value, even if the underlying assertion provides a default message. -
event.defaultMessage
- If you use objects instead of strings to specify patterns (see below), thedefaultMessage
metadata will be copied directly on the event object. -
event.matcherSpec
- This contains the complete parsed matcher spec as supplied, as well as any additional metadata you may have supplied (see patterns section below for details on how to supply additional metadata). -
event.args
- An array of the actual arguments passed to the assertion. -
event.assertionThrew
- Whether or not the underlying assertion threw an error. This will always betrue
in anonError
callback, and alwaysfalse
in anonSuccess
callback. -
event.error
- Only present ifevent.assertionThrew === true
. Contains the error thrown by the underlying assertion method. -
event.returnValue
- Only present ifevent.assertionThrew === false
. Contains the value return value returned by the underlying assertion method. -
event.powerAssertContext
- Only present for methods that matchpatterns
, and only in code that has been enhanced with the power-assert transform. It contains the information necessary for power-assert renderers to generate their output. Implementors ofonError
should usually attach it to the error objectfunction onError (errorEvent) { var e = errorEvent.error; if (errorEvent.powerAssertContext && /^AssertionError/.test(e.name)) { e.powerAssertContext = errorEvent.powerAssertContext; } throw e; }
options.modifyMessageBeforeAssert
type | default value |
---|---|
function |
N/A |
TBD
options.patterns
type | default value |
---|---|
Array of string or objects |
objects shown below |
[
'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 call-signature. Any arguments enclosed in bracket (for example, [message]
) means optional parameters. Without bracket means mandatory parameters.
Instead of a string, you may alternatively specify an object with a pattern
property, and any other arbitrary data.
Currently only defaultMessage
is formally recommended, but you can attach any data here and it will be passed to the onSuccess
and onError
handlers.
[
{
pattern: 'assert.fail([message])',
defaultMessage:'assert.fail() was called!!'
},
...
]
options.wrapOnlyPatterns
type | default value |
---|---|
Array of string |
empty array |
Methods matching these patterns will not be instrumented by the code transform, but they will be wrapped at runtime and trigger events in the onSuccess
and onError
callbacks. Note that "wrap only" events will never have a powerAssertContext
property.
Similar to the options.patterns
, you may supply objects with a pattern
member, and the additional metadata will be passed to the assertion listeners.
var options = empowerCore.defaultOptions();
Returns default options object for empowerCore
function. In other words, returns
{
destructive: false,
onError: onError,
onSuccess: onSuccess,
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])'
]
}
with sensible default for onError
and onSuccess
function onError (errorEvent) {
var e = errorEvent.error;
if (errorEvent.powerAssertContext && e.name === 'AssertionError') {
e.powerAssertContext = errorEvent.powerAssertContext;
}
throw e;
}
function onSuccess(successEvent) {
return successEvent.returnValue;
}
SUPPORTED ASSERTION LIBRARIES
ASSERTION LIBRARIES KNOWN TO WORK
INSTALL
via npm
Install
$ npm install --save-dev empower-core
use empower-core npm module on browser
empowerCore
function is exported
<script type="text/javascript" src="./path/to/node_modules/empower-core/build/empower-core.js"></script>
via bower
Install
$ bower install --save-dev empower-core
Then load (empowerCore
function is exported)
<script type="text/javascript" src="./path/to/bower_components/empower-core/build/empower-core.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-core is known to work with old browsers, and trying to keep them working though.
AUTHOR
CONTRIBUTORS
LICENSE
Licensed under the MIT license.