lepu-test-platform-web/node_modules/postcss-message-helpers/README.md

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# postcss-message-helpers [![Build Status](https://travis-ci.org/MoOx/postcss-message-helpers.png)](https://travis-ci.org/MoOx/postcss-message-helpers)
> [PostCSS](https://github.com/postcss/postcss) helpers to throw or output GNU style messages.
This modules offers you some function to throw or just output messages with [GNU style](https://www.gnu.org/prep/standards/html_node/Errors.html): `sourcefile:lineno:column: message`
## Installation
```console
$ npm install postcss-message-helpers
```
```js
var messageHelpers = require("postcss-message-helpers")
```
## Usage
### `var fnValue = messageHelpers.try(fn, source)`
Execute `fn` an return the value.
If an exception is thrown during the process, the exception will be catched, enhanced from source & re-throw.
### `var sourceMessage = messageHelpers.message(message, source)`
Returns a message like `sourcefile:lineno:column: message`.
`source` should be a postcss source object from a node.
### `var source = messageHelpers.source(source)`
Returns `sourcefile:lineno:column` for a given `source` postcss object.
### Example
```js
// dependencies
var fs = require("fs")
var postcss = require("postcss")
var messageHelpers = require("postcss-message-helpers")
// css to be processed
var css = fs.readFileSync("input.css", "utf8")
// process css
var output = postcss()
.use(function(styles) {
styles.eachDecl(function transformDecl(decl) {
// will catch, adjust error stack, line, column & message (gnu style) then re-throw
messageHelpers.try(function IwillThrow() {
if (decl.value.indexOf("error(") > -1) {
throw new Error("error detected: " + decl.value)
}
}, decl.source)
// will output a gnu style warning
if (decl.value.indexOf("warning(") > -1) {
console.warning(messageHelpers.message("warning: " + decl.value, decl.source))
}
})
})
.process(css)
.css
```
Checkout [tests](test) for more examples.
---
## Contributing
Work on a branch, install dev-dependencies, respect coding style & run tests before submitting a bug fix or a feature.
$ git clone https://github.com/MoOx/postcss-message-helpers.git
$ git checkout -b patch-1
$ npm install
$ npm test
## [Changelog](CHANGELOG.md)
## [License](LICENSE)