espower-source
================================
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Power Assert instrumentor from code to code, with SourceMap.
DESCRIPTION
---------------------------------------
`espower-source` is a source code transformer that applies [espower](https://github.com/power-assert-js/espower) to target code.
`espower` manipulates assertion expression in the form of ECMAScript AST defined in [The ESTree Spec](https://github.com/estree/estree) (formerly known as [Mozilla SpiderMonkey Parser API](https://developer.mozilla.org/en-US/docs/SpiderMonkey/Parser_API)), to instrument power-assert feature into the code. SourceMap information is appended in SourceMap Comment syntax at the end of returned code.
Pull-requests, issue reports and patches are always welcomed. See [power-assert](https://github.com/power-assert-js/power-assert) project for more documentation.
CHANGELOG
---------------------------------------
See [CHANGELOG](https://github.com/power-assert-js/espower-source/blob/master/CHANGELOG.md)
API
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### var modifiedCode = espowerSource(originalCode, [filepath], [options])
| return type |
|:------------|
| `string` |
`espowerSource` function manipulates `originalCode` then returns (transformed) JavaScript code as string. SourceMap information is appended in SourceMap Comment syntax at the end of returned code.
#### originalCode
| type | default value |
|:---------|:--------------|
| `string` | N/A |
Original JavaScript source code that is a source of code transformation. If not specified, then `EspowerError` will be thrown.
#### filepath (optional but recommended)
| type | default value |
|:---------|:--------------|
| `string` | N/A |
Filepath of `originalCode`. espower-source stores filepath information for later reporting. If not specified, `options.path` will be used. If neither filepath nor options.path are not specified, espower-source transforms code as usual but SourceMap will not be generated and attached.
#### options (optional)
| type | default value |
|:---------|:--------------|
| `object` | (return value of `espower.defaultOptions()` but with `destructive` option is `true`) |
Configuration options for `espower` module. If not passed, default options (Same as [espower.defaultOptions()](https://github.com/power-assert-js/espower#var-options--espowerdefaultoptions)) will be used, but `options.destructive` is set to `true`, and if `options.path` is falsy, `options.path` is set to value of `filepath` argument by espower-source module.
#### options.ecmaVersion
| type | default value |
|:---------|:--------------|
| `number` | `2018` |
The ECMAScript version to parse and analyze. Must be either 3, 5, 6 (2015), 2016, 2017, or 2018.
#### options.sourceType
| type | default value |
|:---------|:--------------|
| `string` | `'module'` |
The source type of the code. Must be either `"script"` or `"module"`.
INSTALL
---------------------------------------
### via npm
Install
$ npm install --save-dev espower-source
OUR SUPPORT POLICY
---------------------------------------
We support Node under maintenance. In other words, we stop supporting old Node version when [their maintenance ends](https://github.com/nodejs/LTS).
This means that any other environment is not supported.
NOTE: If espower-source works in any of the unsupported environments, it is purely coincidental and has no bearing on future compatibility. Use at your own risk.
AUTHOR
---------------------------------------
* [Takuto Wada](https://github.com/twada)
CONTRIBUTORS
---------------------------------------
* [azu](https://github.com/azu)
* [James Talmage (jamestalmage)](https://github.com/jamestalmage)
* [Yoshiki Shibukawa (shibukawa)](https://github.com/shibukawa)
* [Yiyu He (dead-horse)](https://github.com/dead-horse)
* [Eward Song (shepherdwind)](https://github.com/shepherdwind)
LICENSE
---------------------------------------
Licensed under the [MIT](https://github.com/power-assert-js/espower-source/blob/master/MIT-LICENSE.txt) license.
[npm-url]: https://npmjs.org/package/espower-source
[npm-image]: https://badge.fury.io/js/espower-source.svg
[travis-url]: https://travis-ci.org/power-assert-js/espower-source
[travis-image]: https://secure.travis-ci.org/power-assert-js/espower-source.svg?branch=master
[depstat-url]: https://gemnasium.com/power-assert-js/espower-source
[depstat-image]: https://gemnasium.com/power-assert-js/espower-source.svg
[license-url]: https://github.com/power-assert-js/espower-source/blob/master/MIT-LICENSE.txt
[license-image]: https://img.shields.io/badge/license-MIT-brightgreen.svg?style=flat