PostCSS helpers to throw or output GNU style messages

Usage no npm install needed!

<script type="module">
  import postcssMessageHelpers from '';


postcss-message-helpers Build Status

PostCSS helpers to throw or output GNU style messages.

This modules offers you some function to throw or just output messages with GNU style: sourcefile:lineno:column: message


$ npm install postcss-message-helpers
var messageHelpers = require("postcss-message-helpers")


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.


// 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))

Checkout tests for more examples.


Work on a branch, install dev-dependencies, respect coding style & run tests before submitting a bug fix or a feature.

$ git clone
$ git checkout -b patch-1
$ npm install
$ npm test