Log PostCSS warnings in the console.

As of PostCSS 4.1, a single PostCSS process can accumulate warnings from all of the plugins it uses. Presumably, plugin authors want you to see those warnings. So this plugin exists to read the accumulated warnings (or warnings from only the plugins you've specified), format them for human legibility, and print them to the console.

Something like this (using fake plugins) ...

test/forVisual.css
2:3   [reject-colors] no colors allowed
6:1	  [reject-colors] no colors allowed
7:6   [reject-backgrounds] no backgrounds allowed

... except that the plugin uses chalk for helpful coloring & formatting in the console output.

npm install postcss-log-warnings

Add it to your plugin list after any plugins whose warnings you want to log, and pass it an object of options.

For example, using gulp-postcss:

gulp.task('css', function() {
  return gulp.src('./src/*.css')
    .pipe(postcss([
      bemLinter(),
      customProperties(),
      calc(),
      rejectAllColors(),
      logWarnings(myOptions) // <------ ding
    ]))
    .pipe(gulp.dest('./dist'));
});

• plugins (array of strings, default = []): If empty, logWarnings will log every warning, regardless of which plugin registered it. To limit output, name the plugins whose warnings you would like to see. For example, { plugins: ['postcss-bem-linter'] } will only log warnings from the postcss-bem-linter plugin.
• throwError (boolean, default = false): If true, after logWarnings logs your warnings it will exit the process with code 1 if it found any warnings.