[![test][test]][test-url]

CI Cache Loader

Caches the result of following loaders on disk

How does this differ from cache-loader?

cache-loader is excellent for development mode. However, it may have reduced in peformance in continuous integration environments due to:

• Git checkouts assigning arbitrary timestamps to source files
• npm/yarn installation assigning arbitrary timestamps node_modules files
• Cache restoration assigning arbitrary timestamps to node_modules file

ci-cache-loader works around these problems by:

• Tracking cached files by hash instead of last modified time
• Tracking npm dependencies by package version instead of last modified time

Can I just use this for development?

No. cache-loader is much better at reacting to development environment changes. This loader assumes that:

• node_modules is an unmodified version of code installed via npm/yarn (i.e., no patches, or modification by build scripts)
• All source code is untouched during webpack compilation
• thread-loader isn't used (CI servers tend to restrict thread counts anyway)

Install

yarn

Usage

Add this loader in front of other (expensive) loaders to cache the result on disk.

webpack.config.js

module.exports = {
  module: {
    rules: [
      {
        test: /\.ext$/,
        use: ['@shopify/ci-cache-loader', ...loaders],
        include: path.resolve('src'),
      },
    ],
  },
};

⚠️ Note that there is an overhead for saving the reading and saving the cache file, so only use this loader to cache expensive loaders.

Options

| Name | Type | Default | Description | | --------------------- | ------------------------------------------------ | ----------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | cacheKey | {Function(options, request) -> {String}} | undefined | Allows you to override default cache key generator | | cacheDirectory | {String} | path.resolve('.cache-loader') | Provide a cache directory where cache items should be stored (used for default read/write implementation) | | cacheIdentifier | {String} | cache-loader:{version} {process.env.NODE_ENV} | Provide an invalidation identifier which is used to generate the hashes. You can use it for extra dependencies of loaders (used for default read/write implementation) | | write | {Function(cacheKey, data, callback) -> {void}} | undefined | Allows you to override default write cache data to file (e.g. Redis, memcached) | | read | {Function(cacheKey, callback) -> {void}} | undefined | Allows you to override default read cache data from file |