JarCastingWebpack Assets Manifest
This webpack plugin will generate a JSON file that matches the original filename with the hashed version.
Installation
npm install webpack-assets-manifest --save-dev
New in version 5
- Compatible with webpack 5 only (5.1+ required).
- Supports finding asset modules.
- Updated options schema to prevent additional properties. This helps with catching typos in option names.
-
⚠️ Updated default value of theoutputoption to beassets-manifest.json. This is to prevent confusion when working with Web app manifests or WebExtension manifests.
New in version 4
-
Requires Node 10+.
-
Compatible with webpack 4 only (4.40+ required).
-
Added options:
enabled,entrypointsUseAssets,contextRelativeKeys. -
Updated
writeToDiskoption to default toauto. -
Use lock files for various operations.
-
donehook is now anAsyncSeriesHook. -
⚠️ The structure of theentrypointsdata has been updated to includepreloadandprefetchassets. Assets for an entrypoint are now included in anassetsproperty under the entrypoint.Example:
{ "entrypoints": { "main": { "assets": { "css": [ "main.css" ], "js": [ "main.js" ] }, "prefetch": { "js": [ "prefetch.js" ] }, "preload": { "js": [ "preload.js" ] } } } }
Usage
In your webpack config, require the plugin then add an instance to the plugins array.
const path = require('path');
const WebpackAssetsManifest = require('webpack-assets-manifest');
module.exports = {
entry: {
// Your entry points
},
output: {
path: path.join( __dirname, 'dist' ),
filename: '[name]-[hash].js',
chunkFilename: '[id]-[chunkhash].js',
},
module: {
// Your loader rules go here.
},
plugins: [
new WebpackAssetsManifest({
// Options go here
}),
],
};
Sample output
{
"main.js": "main-9c68d5e8de1b810a80e4.js",
"main.css": "main-9c68d5e8de1b810a80e4.css",
"images/logo.svg": "images/logo-b111da4f34cefce092b965ebc1078ee3.svg"
}
Options (read the schema)
enabled
Type: boolean
Default: true
Is the plugin enabled?
output
Type: string
Default: assets-manifest.json
This is where to save the manifest file relative to your webpack output.path.
assets
Type: object
Default: {}
Data is stored in this object.
Sharing data
You can share data between instances by passing in your own object in the assets option.
This is useful in multi-compiler mode.
const data = Object.create(null);
const manifest1 = new WebpackAssetsManifest({
assets: data,
});
const manifest2 = new WebpackAssetsManifest({
assets: data,
});
contextRelativeKeys
Type: boolean
Default: false
Keys are relative to the compiler context.
space
Type: int
Default: 2
Number of spaces to use for pretty printing.
replacer
Type: null, function, or array
Default: null
You'll probably want to use the transform hook instead.
fileExtRegex
Type: regex
Default: /\.\w{2,4}\.(?:map|gz)$|\.\w+$/i
This is the regular expression used to find file extensions. You'll probably never need to change this.
writeToDisk
Type: boolean, string
Default: 'auto'
Write the manifest to disk using fs.
webpack-dev-server to process your assets during development, you should set writeToDisk: true and provide an absolute path in output so the manifest file is actually written to disk and not kept only in memory.
sortManifest
Type: boolean, function
Default: true
The manifest is sorted alphabetically by default. You can turn off sorting by setting sortManifest: false.
If you want more control over how the manifest is sorted, you can provide your own comparison function. See the sorted example.
new WebpackAssetsManifest({
sortManifest(a, b) {
// Return -1, 0, or 1
}
});
merge
Type: boolean, string
Default: false
If the output file already exists and you'd like to add to it, use merge: true. The default behavior is to use the existing keys/values without modification.
new WebpackAssetsManifest({
output: '/path/to/manifest.json',
merge: true
});
If you need to customize during merge, use merge: 'customize'.
If you want to know if customize was called when merging with an existing manifest, you can check manifest.isMerging.
new WebpackAssetsManifest({
merge: 'customize',
customize(entry, original, manifest, asset) {
if ( manifest.isMerging ) {
// Do something
}
},
}),
publicPath
Type: string, function, boolean,
Default: null
When using publicPath: true, your webpack config output.publicPath will be used as the value prefix.
const manifest = new WebpackAssetsManifest({
publicPath: true,
});
When using a string, it will be the value prefix. One common use is to prefix your CDN URL.
const manifest = new WebpackAssetsManifest({
publicPath: '//cdn.example.com',
});
If you'd like to have more control, use a function. See the custom CDN example.
const manifest = new WebpackAssetsManifest({
publicPath(filename, manifest)
{
// customize filename here
return filename;
}
});
entrypoints
Type: boolean
Default: false
Include compilation.entrypoints in the manifest file.
entrypointsKey
Type: string, boolean
Default: entrypoints
If this is set to false, the entrypoints will be added to the root of the manifest.
entrypointsUseAssets
Type: boolean
Default: false
Entrypoint data should use the value from assets, which means the values could be customized and not just a string file path. This new option defaults to false so the new behavior is opt-in.
integrity
Type: boolean
Default: false
Include the subresource integrity hash.
integrityHashes
Type: array
Default: [ 'sha256', 'sha384', 'sha512' ]
Hash algorithms to use when generating SRI. For browsers, the currently the allowed integrity hashes are sha256, sha384, and sha512.
Other hash algorithms can be used if your target environment is not a browser. If you were to create a tool to audit your S3 buckets for data integrity, you could use something like this example to record the md5 hashes.
integrityPropertyName
Type: string
Default: integrity
This is the property that will be set on each entry in compilation.assets, which will then be available during customize. It is customizable so that you can have multiple instances of this plugin and not have them overwrite the currentAsset.integrity property.
You'll probably only need to change this if you're using multiple instances of this plugin to create different manifests.
apply
Type: function
Default: null
Callback to run after setup is complete.
customize
Type: function
Default: null
Callback to customize each entry in the manifest.
transform
Type: function
Default: null
Callback to transform the entire manifest.
done
Type: function
Default: null
Callback to run after the compilation is done and the manifest has been written.
Hooks
This plugin is using hooks from Tapable.
The apply, customize, transform, and done options are automatically tapped into the appropriate hook.
| Name | Type | Callback signature |
|---|---|---|
apply |
SyncHook |
function(manifest){} |
customize |
SyncWaterfallHook |
function(entry, original, manifest, asset){} |
transform |
SyncWaterfallHook |
function(assets, manifest){} |
done |
AsyncSeriesHook |
async function(manifest, stats){} |
options |
SyncWaterfallHook |
function(options){} |
afterOptions |
SyncHook |
function(options){} |
Tapping into hooks
Tap into a hook by calling the tap method on the hook as shown below.
If you want more control over exactly what gets added to your manifest, then use the customize and transform hooks. See the customized and transformed examples.
const manifest = new WebpackAssetsManifest();
manifest.hooks.apply.tap('YourPluginName', function(manifest) {
// Do something here
manifest.set('some-key', 'some-value');
});
manifest.hooks.customize.tap('YourPluginName', function(entry, original, manifest, asset) {
// customize entry here
return entry;
});
manifest.hooks.transform.tap('YourPluginName', function(assets, manifest) {
// customize assets here
return assets;
});
manifest.hooks.options.tap('YourPluginName', function(options) {
// customize options here
return options;
});
manifest.hooks.done.tap('YourPluginName', function(manifest, stats) {
console.log(`The manifest has been written to ${manifest.getOutputPath()}`);
console.log(`${manifest}`);
});
manifest.hooks.done.tapPromise('YourPluginName', async (manifest, stats) => {
await yourAsyncOperation();
});
These hooks can also be set by passing them in the constructor options.
new WebpackAssetsManifest({
done(manifest, stats) {
console.log(`The manifest has been written to ${manifest.getOutputPath()}`);
console.log(`${manifest}`);
}
});
Manifest methods
If the manifest instance is passed to a hook, you can use the following methods to manage what goes into the manifest.
has(key)get(key)set(key, value)setRaw(key, value)delete(key)
If you want to write the manifest to another location, you can use writeTo(destination).
new WebpackAssetsManifest({
async done(manifest) {
await manifest.writeTo('/some/other/path/assets-manifest.json');
}
});