gulp-async-replace

A string replace plugin for Gulp 4

Usage

First, install gulp-async-replace as a development dependency:

npm install --save-dev gulp-replace

Then, add it to your gulpfile.js:

Simple string replace

const replace = require('gulp-replace');

gulp.task('templates', function(){
  gulp.src(['file.txt'])
    .pipe(replace('bar', 'foo'))
    .pipe(gulp.dest('build/'));
});

Simple regex replace

const replace = require('gulp-replace');

gulp.task('templates', function(){
  gulp.src(['file.txt'])
    // See https://mdn.io/string.replace#Specifying_a_string_as_a_parameter
    .pipe(replace(/foo(.{3})/g, '$1foo'))
    .pipe(gulp.dest('build/'));
});

String replace with function callback

const replace = require('gulp-replace');

gulp.task('templates', function(){
  gulp.src(['file.txt'])
    .pipe(replace('foo', function(match) {
      // Replaces instances of "foo" with "oof"
      return match.reverse();
    }))
    .pipe(gulp.dest('build/'));
});

String replace with async function callback

const replace = require('gulp-replace');
const fs = require('fs');
const {promisify} = require('util');

const readFile = promisfy(fs.readFile);

gulp.task('templates', function(){
  gulp.src(['file.txt'])
    .pipe(replace('foo', async function(match) {
      const token = await readFile('token.txt', {encoding: 'utf8'});
      // replace foo by a token contained in 'token.txt'
      return token;
    }))
    .pipe(gulp.dest('build/'));
});

Regex replace with function callback

const replace = require('gulp-replace');

gulp.task('templates', function(){
  gulp.src(['file.txt'])
    .pipe(replace(/foo(.{3})/g, function(match, p1, offset, string) {
      // Replace foobaz with barbaz and log a ton of information
      // See https://mdn.io/string.replace#Specifying_a_function_as_a_parameter
      console.log('Found ' + match + ' with param ' + p1 + ' at ' + offset + ' inside of ' + string);
      return 'bar' + p1;
    }))
    .pipe(gulp.dest('build/'));
});

Regex replace with function callback

const replace = require('gulp-replace');
const fs = require('fs');
const {promisify} = require('util');

const readFile = promisfy(fs.readFile);

gulp.task('templates', function(){
  gulp.src(['file.txt'])
    .pipe(replace(/foo(.{3})/g, async function(match, p1, offset, string) {
      console.log('Found ' + match + ' with param ' + p1 + ' at ' + offset + ' inside of ' + string);
      const token = await readFile('token.txt', {encoding: 'utf8'});
      return token;
    }))
    .pipe(gulp.dest('build/'));
});

Function callback with file object

const replace = require('gulp-replace');

gulp.task('templates', function(){
  gulp.src(['file.txt'])
    .pipe(replace('filename', function() {
      // Replaces instances of "filename" with "file.txt"
      // this.file is also available for regex replace
      // See https://github.com/gulpjs/vinyl#instance-properties for details on available properties
      return this.file.relative;
    }))
    .pipe(gulp.dest('build/'));
});

API

gulp-replace can be called with a string or regex.

replace(string, replacement[, options])

string

Type: String

The string to search for.

replacement

Type: String or Function or AsyncFunction

The replacement string or function. If replacement is a function, it will be called once for each match and will be passed the string that is to be replaced.

The value of this.file will be equal to the vinyl instance for the file being processed.

replace(regex, replacement[, options])

regex

Type: RegExp

The regex pattern to search for. See the MDN documentation for RegExp for details.

replacement

Type: String or Function or AsyncFunction

The replacement string or function. See the MDN documentation for String.replace for details on special replacement string patterns and arguments to the replacement function.

The value of this.file will be equal to the vinyl instance for the file being processed.

gulp-replace options

An optional third argument, options, can be passed.

options

Type: Object

options.skipBinary

Type: boolean
Default: true

Skip binary files. This option is true by default. If you want to replace content in binary files, you must explicitly set it to false