babel-plugin-espower

babel-plugin-espower
================================

Babel plugin for power-assert.

[![Build Status][travis-image]][travis-url]
[![NPM version][npm-image]][npm-url]
[![Dependency Status][depstat-image]][depstat-url]
[![License][license-image]][license-url]

DESCRIPTION
---------------------------------------

babel-plugin-espower is a Babel plugin for power-assert.

power-assert provides descriptive assertion messages for your tests, like this.

``
1) ES6 demo Destructuring and TemplateLiteral:

AssertionError: # test/demo_test.js:7

assert(${ alice.name } and ${ bob.name } === bob and alice)
| | | | | | |
| | | | | | "bob and alice"
| | | | "bob" false
| | "alice" Object{name:"bob"}
| Object{name:"alice"}
"alice and bob"

--- [string] bob and alice
+++ [string] ${ alice.name } and ${ bob.name }
@@ -1,13 +1,13 @@
-bob and alice
+alice and bob
`

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


FYI: There's a babel preset for all power-assert plugins


INSTALL
---------------------------------------

`
$ npm install --save-dev babel-plugin-espower
`


CAUTION
---------------------------------------

Babel7 is incompatible with Babel6. Babel6 is incompatible with Babel5.

For Babel6, you need to use the 2.x release of babel-plugin-espower.

`
$ npm install --save-dev babel-plugin-espower@2
`

For Babel5 or lower, you need to use the 1.x release of babel-plugin-espower.

`
$ npm install --save-dev babel-plugin-espower@1
`


HOW TO USE
---------------------------------------

$3

`javascript
{
"presets": [
...
],
"plugins": [
"babel-plugin-espower"
]
}
`

`
$ babel /path/to/test/some_test.js > /path/to/build/some_test.js
`

For example, with @babel/register module and .babelrc above, you can run mocha without code generation steps.

`
$ $(npm bin)/mocha --require @babel/register test/some_test.js
`

$3

`javascript
var babel = require('@babel/core');
var jsCode = fs.readFileSync('/path/to/test/some_test.js');
var transformed = babel.transform(jsCode, {
presets: [...],
plugins: ['babel-plugin-espower']
});
console.log(transformed.code);
`

$3

`javascript
require('@babel/register')({
presets: [...],
plugins: ['babel-plugin-espower']
});
`

For example, with babel_hook.js above, you can run mocha without code generation steps.

`
$ $(npm bin)/mocha --require ./babel_hook /path/to/test/demo_test.js
`

$3

`javascript
var fs = require('fs');
var browserify = require('browserify');
var babelify = require('babelify');
var glob = require('glob'),
browserify({ entries: glob.sync('./test/*_test.js'), debug: true })
.transform(babelify.configure({
presets: [...],
plugins: ['babel-plugin-espower']
}))
.bundle()
.on('error', function (err) { console.log('Error : ' + err.message); })
.pipe(fs.createWriteStream('all_test.js'));
`

`
$ $(npm bin)/browserify -d -e ./test/*_test.js -t [ babelify --presets ... --plugins babel-plugin-espower ]
`

$3

`javascript
var source = require('vinyl-source-stream');
var browserify = require('browserify');
var glob = require('glob'),
gulp.task('build_test', function() {
var files = glob.sync('./test/*_test.js');
var b = browserify({entries: files, debug: true});
b.transform(babelify.configure({
presets: [...],
plugins: ['babel-plugin-espower']
}));
return b.bundle()
.pipe(source('all_test.js'))
.pipe(gulp.dest('./build'));
});
`

$3

`javascript
module.exports = function(config) {
config.set({
frameworks: ['mocha', 'browserify'],
files: [
"test/*/.js"
],
preprocessors: {
"test/*/.js": "browserify"
},
browserify: {
debug: true,
transform: [
[
'babelify', {
presets: [...],
plugins: ['babel-plugin-espower']
}
]
]
},
// ...
`


EXAMPLE
---------------------------------------


For given test file test/demo_test.js below,

`javascript
import assert from 'power-assert';

describe('ES6 demo', () => {

it('Destructuring and TemplateLiteral', () => {
let [alice, bob] = [ { name: 'alice' }, { name: 'bob' } ];
assert(${alice.name} and ${bob.name} === bob and alice);
});

it('ArrowFunctionExpression and SpreadElement', () => {
let seven = 7, ary = [4, 5];
assert(seven === ((v, i) => v + i)(...[...ary]));
});

it('Enhanced Object Literals', () => {
let name = 'bobby';
assert.deepEqual({
name,
[ ${name}'s greet ]: Hello, I'm ${name}
}, null);
});

});
`

prepare babel_hook.js to transform tests.

`javascript
{
"presets": [
...
],
"plugins": [
"babel-plugin-espower"
]
}
`

Run mocha with --require @babel/register option. You will see the power-assert output appears.

`
$ $(npm bin)/mocha --require @babel/register test/demo_test.js

ES6 demo
1) Destructuring and TemplateLiteral
2) ArrowFunctionExpression and SpreadElement
3) Enhanced Object Literals


0 passing
3 failing

1) ES6 demo Destructuring and TemplateLiteral:

AssertionError: # test/demo_test.js:7

assert(${ alice.name } and ${ bob.name } === bob and alice)
| | | | | | |
| | | | | | "bob and alice"
| | | | "bob" false
| | "alice" Object{name:"bob"}
| Object{name:"alice"}
"alice and bob"

--- [string] bob and alice
+++ [string] ${ alice.name } and ${ bob.name }
@@ -1,13 +1,13 @@
-bob and alice
+alice and bob

at Context. (test/demo_test.js:19:28)

2) ES6 demo ArrowFunctionExpression and SpreadElement:

AssertionError: # test/demo_test.js:12

assert(seven === ((v, i) => v + i)(...[...ary]))
| | | | |
| | | | [4,5]
| | 9 [4,5]
7 false

[number] ((v, i) => v + i)(...[...ary])
=> 9
[number] seven
=> 7

at Context. (test/demo_test.js:29:28)

3) ES6 demo Enhanced Object Literals:
AssertionError: # test/demo_test.js:17

assert.deepEqual({name,[${ name }'s greet]: Hello, I'm ${ name }}, null)
| | | | |
| | | | "bobby"
| | "bobby" "Hello, I'm bobby"
| "bobby's greet"
Object{name:"bobby","bobby's greet":"Hello, I'm bobby"}

at Context. (test/demo_test.js:40:29)
`


CUSTOMIZE
---------------------------------------

$3

You can customize configs such as assertion patterns via .babelrc

`javascript
{
"presets": [
...
],
"plugins": [
["babel-plugin-espower", {
"embedAst": true,
"patterns": [
"assert.isNull(object, [message])",
"assert.same(actual, expected, [message])",
"assert.near(actual, expected, delta, [message])"
]
}]
]
}
`

or via Require Hook.

`javascript
require('@babel/register')({
presets: [...],
plugins: [
['babel-plugin-espower', {
embedAst: true,
patterns: [
'assert.isNull(object, [message])',
'assert.same(actual, expected, [message])',
'assert.near(actual, expected, delta, [message])'
]
}]
]
});
`

or via Babel API,

`javascript
var babel = require('@babel/core');
var jsCode = fs.readFileSync('/path/to/test/some_test.js');
var transformed = babel.transform(jsCode, {
presets: [...],
plugins: [
['babel-plugin-espower', {
embedAst: true,
patterns: [
'assert.isNull(object, [message])',
'assert.same(actual, expected, [message])',
'assert.near(actual, expected, delta, [message])'
]
}]
]
});
console.log(transformed.code);
`

#### options

| type | default value |
|:---------|:--------------------|
| object | objects shown below |

Configuration options for babel-plugin-espower. If not passed, default options will be used (return value of defaultOptions() with default embedAst, visitorKeys, astWhiteList, path, sourceRoot and sourceMap. visitorKeys is value of babel.types.VISITOR_KEYS. astWhiteList is value of babel.types.BUILDER_KEYS. path is filename passed to babel. sourceRoot is be return value of process.cwd(), sourceMap is babel's internal SourceMap object).

`javascript
{
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])'
],
embedAst: true,
visitorKeys: babel.types.VISITOR_KEYS,
astWhiteList: babel.types.BUILDER_KEYS,
sourceRoot: process.cwd(),
path: file.opts.filename,
sourceMap: file.inputMap ? file.inputMap.toObject() : false
}
`

#### options.embedAst

If you want to use non-ECMASCript-standard features such as JSX tags in your assert(), you should set embedAst option to true.

`js
assert(shallow().is('.foo'));
``

CHANGELOG
---------------------------------------
See CHANGELOG

AUTHOR
---------------------------------------
* Takuto Wada

CONTRIBUTORS
---------------------------------------
* James Talmage (jamestalmage)

OUR SUPPORT POLICY
---------------------------------------

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

This means that any other environment is not supported.

NOTE: If babel-plugin-espower works in any of the unsupported environments, it is purely coincidental and has no bearing on future compatibility. Use at your own risk.

LICENSE
---------------------------------------
Licensed under the MIT license.

[npm-url]: https://npmjs.org/package/babel-plugin-espower
[npm-image]: https://badge.fury.io/js/babel-plugin-espower.svg

[travis-url]: https://travis-ci.org/power-assert-js/babel-plugin-espower
[travis-image]: https://secure.travis-ci.org/power-assert-js/babel-plugin-espower.svg?branch=master

[depstat-url]: https://gemnasium.com/power-assert-js/babel-plugin-espower
[depstat-image]: https://gemnasium.com/power-assert-js/babel-plugin-espower.svg

[license-url]: https://github.com/power-assert-js/babel-plugin-espower/blob/master/LICENSE
[license-image]: https://img.shields.io/badge/license-MIT-brightgreen.svg