gulp-error

A Gulp plugin that helps testing streams by throwing controlled errors on target files

Usage

This Gulp plugin main goal is to test callback functions when 'error' events are emitted by a stream. Rather than editing files, deleting them, renaming them, you may just use this plugin to throw a controlled error when the targeted vinyl is passed through.

import gulp from 'gulp';
import error from 'gulp-error';

gulp.task('test1', () => {
  // Throws 'Intentional error when processing file src/app.js' if file
  // is in the stream.
  return gulp.src('**/*.js')
    .pipe(error('src/app.js'))
    .pipe(gulp.dest('build'));

gulp.task('test2', () => {
  // Throws same error for first js file (if any) found under test directory.
  return gulp.src('**/*.js')
    .pipe(error('test/**/*.js'))
    .pipe(gulp.dest('build'));

gulp.task('test3', () => {
  // Throws same error for file a.js (if found and if alphabetically ordered
  // stream).
  return gulp.src('**/*.js')
    .pipe(error(['b.js', 'a.js', 'c.js']))
    .pipe(gulp.dest('build'));
});

gulp.task('test4', () => {
  // Throws a reference error with message 'variable x is undefined' on file
  // a.js (if found).
  return gulp.src('**/*.js')
    .pipe(error({
      files: 'a.js',
      ErrorType: ReferenceError,
      message: 'variable x is undefined'
    }))
    .pipe(gulp.dest('build'));
});

Arguments

Files arguments, whether directly or as an option field files, can be one of the following:

• file name string: 'a.js',
• list of file name strings: ['a.js', 'b.js'],
• glob: 'src/*.js',
• list of globs: ['src/*.js', 'test/*.js'],
• list of files and globs: ['a.js', 'src/*.js'].

Unless you recover from the error, an error is thrown only for the first match.

When no file argument is provided, the plugin throws on the first vinyl passed through.

Rather than a direct files argument, you can pass an option object with the following fields (all are optional):

• files: see above,
• ErrorType: a constructor for an error type such as TypeError or ReferenceError,
• message: the error message to be thrown.

License

gulp-error is MIT licensed.