13 KiB
gulp-sourcemaps
Branching
2.X now supports node 0.10+ due to switching out a dependency.
Usage
Write inline source maps
Inline source maps are embedded in the source file.
Example:
var gulp = require('gulp');
var plugin1 = require('gulp-plugin1');
var plugin2 = require('gulp-plugin2');
var sourcemaps = require('gulp-sourcemaps');
gulp.task('javascript', function() {
gulp.src('src/**/*.js')
.pipe(sourcemaps.init())
.pipe(plugin1())
.pipe(plugin2())
.pipe(sourcemaps.write())
.pipe(gulp.dest('dist'));
});
All plugins between sourcemaps.init()
and sourcemaps.write()
need to have support for gulp-sourcemaps
. You can find a list of such plugins in the wiki.
Write external source map files
To write external source map files, pass a path relative to the destination to sourcemaps.write()
.
Example:
var gulp = require('gulp');
var plugin1 = require('gulp-plugin1');
var plugin2 = require('gulp-plugin2');
var sourcemaps = require('gulp-sourcemaps');
gulp.task('javascript', function() {
gulp.src('src/**/*.js')
.pipe(sourcemaps.init())
.pipe(plugin1())
.pipe(plugin2())
.pipe(sourcemaps.write('../maps'))
.pipe(gulp.dest('dist'));
});
Load existing source maps
To load existing source maps, pass the option loadMaps: true
to sourcemaps.init()
.
Example:
var gulp = require('gulp');
var plugin1 = require('gulp-plugin1');
var plugin2 = require('gulp-plugin2');
var sourcemaps = require('gulp-sourcemaps');
gulp.task('javascript', function() {
gulp.src('src/**/*.js')
.pipe(sourcemaps.init({loadMaps: true}))
.pipe(plugin1())
.pipe(plugin2())
.pipe(sourcemaps.write())
.pipe(gulp.dest('dist'));
});
Handle large files
To handle large files, pass the option largeFile: true
to sourcemaps.init()
.
Example:
var gulp = require('gulp');
var plugin1 = require('gulp-plugin1');
var plugin2 = require('gulp-plugin2');
var sourcemaps = require('gulp-sourcemaps');
gulp.task('javascript', function() {
gulp.src('src/**/*.js')
.pipe(sourcemaps.init({largeFile: true}))
.pipe(plugin1())
.pipe(plugin2())
.pipe(sourcemaps.write())
.pipe(gulp.dest('dist'));
});
Handle source files from different directories
Use the base
option on gulp.src
to make sure all files are relative to a common base directory.
Example:
var gulp = require('gulp');
var plugin1 = require('gulp-plugin1');
var plugin2 = require('gulp-plugin2');
var sourcemaps = require('gulp-sourcemaps');
gulp.task('javascript', function() {
gulp.src(['src/test.js', 'src/testdir/test2.js'], { base: 'src' })
.pipe(sourcemaps.init())
.pipe(plugin1())
.pipe(plugin2())
.pipe(sourcemaps.write('../maps'))
.pipe(gulp.dest('dist'));
});
Alter sources
property on sourcemaps
The exported mapSources
method gives full control over the source paths. It takes a function that is called for every source and receives the default source path as a parameter and the original vinyl file.
Example:
gulp.task('javascript', function() {
var stream = gulp.src('src/**/*.js')
.pipe(sourcemaps.init())
.pipe(plugin1())
.pipe(plugin2())
// be careful with the sources returned otherwise contents might not be loaded properly
.pipe(sourcemaps.mapSources(function(sourcePath, file) {
// source paths are prefixed with '../src/'
return '../src/' + sourcePath;
}))
.pipe(sourcemaps.write('../maps')
.pipe(gulp.dest('public/scripts'));
});
Generate Identity Sourcemap
The exported identityMap
method allows you to generate a full valid source map encoding no changes (slower, only for Javascript and CSS) instead of the default empty source map (no mappings, fast). Use this option if you get missing or incorrect mappings, e.g. when debugging.
Example:
gulp.task('javascript', function() {
var stream = gulp.src('src/**/*.js')
.pipe(sourcemaps.init())
// An identity sourcemap will be generated at this step
.pipe(sourcemaps.identityMap())
.pipe(plugin1())
.pipe(plugin2())
.pipe(sourcemaps.write('../maps')
.pipe(gulp.dest('public/scripts'));
});
Init Options
-
loadMaps
Set to true to load existing maps for source files. Supports the following:
- inline source maps
- source map files referenced by a
sourceMappingURL=
comment - source map files with the same name (plus .map) in the same directory
-
identityMap
This option is deprecated. Upgrade to use our
sourcemap.identityMap
API.
Write Options
-
addComment
By default a comment containing / referencing the source map is added. Set this to
false
to disable the comment (e.g. if you want to load the source maps by header).Example:
gulp.task('javascript', function() { var stream = gulp.src('src/**/*.js') .pipe(sourcemaps.init()) .pipe(plugin1()) .pipe(plugin2()) .pipe(sourcemaps.write('../maps', {addComment: false})) .pipe(gulp.dest('dist')); });
-
includeContent
By default the source maps include the source code. Pass
false
to use the original files.Including the content is the recommended way, because it "just works". When setting this to
false
you have to host the source files and set the correctsourceRoot
. -
sourceRoot
Set the location where the source files are hosted (use this when
includeContent
is set tofalse
). This is usually a URL (or an absolute URL path), not a local file system path. By default the source root is '' or in casedestPath
is set, the relative path from the source map to the source base directory (this should work for many dev environments). If a relative path is used (empty string or one starting with a.
), it is interpreted as a path relative to the destination. The plugin rewrites it to a path relative to each source map.Example:
gulp.task('javascript', function() { var stream = gulp.src('src/**/*.js') .pipe(sourcemaps.init()) .pipe(plugin1()) .pipe(plugin2()) .pipe(sourcemaps.write({includeContent: false, sourceRoot: '/src'})) .pipe(gulp.dest('dist')); });
Example (using a function):
gulp.task('javascript', function() { var stream = gulp.src('src/**/*.js') .pipe(sourcemaps.init()) .pipe(plugin1()) .pipe(plugin2()) .pipe(sourcemaps.write({ includeContent: false, sourceRoot: function(file) { return '/src'; } })) .pipe(gulp.dest('dist')); });
Example (relative path):
gulp.task('javascript', function() { var stream = gulp.src('src/**/*.js') .pipe(sourcemaps.init()) .pipe(plugin1()) .pipe(plugin2()) .pipe(sourcemaps.write('.', {includeContent: false, sourceRoot: '../src'})) .pipe(gulp.dest('dist')); });
In this case for a file written to
dist/subdir/example.js
, the source map is written todist/subdir/example.js.map
and the sourceRoot will be../../src
(resulting in the full source path../../src/subdir/example.js
). -
destPath
Set the destination path (the same you pass to
gulp.dest()
). If the source map destination path is not a sub path of the destination path, this is needed to get the correct path in thefile
property of the source map. In addition, it allows to automatically set a relativesourceRoot
if none is set explicitly. -
sourceMappingURLPrefix
Specify a prefix to be prepended onto the source map URL when writing external source maps. Relative paths will have their leading dots stripped.
Example:
gulp.task('javascript', function() { var stream = gulp.src('src/**/*.js') .pipe(sourcemaps.init()) .pipe(plugin1()) .pipe(plugin2()) .pipe(sourcemaps.write('../maps', { sourceMappingURLPrefix: 'https://asset-host.example.com/assets' })) .pipe(gulp.dest('public/scripts')); });
This will result in a source mapping URL comment like
sourceMappingURL=https://asset-host.example.com/assets/maps/helloworld.js.map
. -
sourceMappingURL
If you need full control over the source map URL you can pass a function to this option. The output of the function must be the full URL to the source map (in function of the output file).
Example:
gulp.task('javascript', function() { var stream = gulp.src('src/**/*.js') .pipe(sourcemaps.init()) .pipe(plugin1()) .pipe(plugin2()) .pipe(sourcemaps.write('../maps', { sourceMappingURL: function(file) { return 'https://asset-host.example.com/' + file.relative + '.map'; } })) .pipe(gulp.dest('public/scripts')); });
This will result in a source mapping URL comment like
sourceMappingURL=https://asset-host.example.com/helloworld.js.map
. -
mapFile
This option allows to rename the map file. It takes a function that is called for every map and receives the default map path as a parameter.
Example:
gulp.task('javascript', function() { var stream = gulp.src('src/**/*.js') .pipe(sourcemaps.init()) .pipe(plugin1()) .pipe(plugin2()) .pipe(sourcemaps.write('../maps', { mapFile: function(mapFilePath) { // source map files are named *.map instead of *.js.map return mapFilePath.replace('.js.map', '.map'); } })) .pipe(gulp.dest('public/scripts')); });
-
mapSources
This option is deprecated. Upgrade to use our
sourcemap.mapSources
API. -
charset
Sets the charset for inline source maps. Default:
utf8
-
clone
Clones the original file for creation of the map file. Could be important if file history is important. See file.clone() for possible options. Default:
{deep:false, contents:false}
Plugin developers only:
-
How to add source map support to plugins
- Generate a source map for the transformation the plugin is applying
- Important: Make sure the paths in the generated source map (
file
andsources
) are relative tofile.base
(e.g. usefile.relative
). - Apply this source map to the vinyl
file
. E.g. by using vinyl-sourcemaps-apply. This combines the source map of this plugin with the source maps coming from plugins further up the chain. - Add your plugin to the wiki page
Example:
var through = require('through2'); var applySourceMap = require('vinyl-sourcemaps-apply'); var myTransform = require('myTransform'); module.exports = function(options) { function transform(file, encoding, callback) { // generate source maps if plugin source-map present if (file.sourceMap) { options.makeSourceMaps = true; } // do normal plugin logic var result = myTransform(file.contents, options); file.contents = new Buffer(result.code); // apply source map to the chain if (file.sourceMap) { applySourceMap(file, result.map); } this.push(file); callback(); } return through.obj(transform); };
-
Verify sourcemaps are working
See example below or refer to test/write.js
Example:
var stream = plugin(); var init = sourcemaps.init(); var write = sourcemaps.write(); init.pipe(stream).pipe(write); write.on('data', function (file) { assert(...); cb(); }); init.write(new gutil.File(...)); init.end();
Debugging
All debugging output relies on visionmedia/debug. Follow the directions to set the
environment variable $DEBUG
.
For a few examples of debug you could use:
DEBUG='gulp-sourcemaps:*' #everything
DEBUG='gulp-sourcemaps:init' #init/index.js
DEBUG='gulp-sourcemaps:init:*' #init/index.internals.js
DEBUG='gulp-sourcemaps:write:' #write/index.js
DEBUG='gulp-sourcemaps:write:*' #write/index.internals.js
DEBUG='gulp-sourcemaps:write:,gulp-sourcemaps:init:**' #write/index.internals.js and init/index.internals.js