gulp-preprocess 
Gulp plugin to preprocess HTML, JavaScript, and other files based on custom context or environment configuration
Information
| Package | gulp-preprocess |
| Node Version | >= 18 |
| Gulp Version | >= 4 |
Usage
Install
npm install gulp-preprocess --save-dev
Examples
Gulpfile
var preprocess = require("gulp-preprocess");
gulp.task("html", function () {
gulp
.src("./app/*.html")
.pipe(preprocess({ context: { NODE_ENV: "production", DEBUG: true } })) // To set environment variables in-line
.pipe(gulp.dest("./dist/"));
});
gulp.task("scripts", function () {
gulp.src(["./app/*.js"]).pipe(preprocess()).pipe(gulp.dest("./dist/"));
});
Example HTML File
<head>
<title>Your App</title>
<!-- @if NODE_ENV='production' -->
<script src="some/production/lib/like/analytics.js"></script>
<!-- @endif -->
</head>
<body>
<!-- @ifdef DEBUG -->
<h1>Debugging mode - <!-- @echo RELEASE_TAG --> </h1>
<!-- @endif -->
<p>
<!-- @include welcome_message.txt -->
</p>
</body>
Example JavaScript File
var configValue = "/* @echo FOO */" || "default value";
// @ifdef DEBUG
someDebuggingCall();
// @endif
CoffeeScript files are also supported.
More Examples
gulp-preprocess uses preprocess. More examples can be found in its README.
API
preprocess(options)
options.context
Type: Object
Default: {}
Context for directives used in your preprocessed files. The default context consists of the current user environment variables. Custom context is merged with process.env.
options.includeBase
Type: String
Base directory for included files. By default, the path to included files is relative to the file currently being processed.
options.extension
Type: String
Override the file extension. This determines what regular expressions are used for comments. You may wish to do this if you are using a custom extension or need to force a particular comment syntax (for example, to allow HTML-style comments in .php files).
LICENSE
The MIT License (MIT)
Copyright (c) 2014 Jason Sandmeyer
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
