JSON Post Process Webpack Plugin

Simple webpack 4 plugin that allows you to modify json files during the emit-phase (when all modules have been sealed and compiled). You can add stuff, remove stuff, or replace the contents completely.

The plugin was written to solve a problem I encountered personally, and so it was only built it for that specific use case. It relies on the native Promise implementation of node, and uses const etc., so it will depend on a somewhat recent version of nodejs.

Usage

Given a webpack project, install it as a local development dependency:

npm install --save-dev json-post-process-webpack-plugin

Then, simply configure it as a plugin in the webpack config:

var JsonPostProcessPlugin = require('json-post-process-webpack-plugin')

module.exports = {
  plugins: [
    new JsonPostProcessPlugin({
      matchers: [{
        matcher: /^json-file-in-your-build.json$/,
        action: (currentJsonContent) => ({ ...currentJsonContent, someNewStuff: '...' })
      }]
    })
  ]
}

Matchers API

The matchers option is an array of objects that have a matcher property (must be a RegExp), and an action property, which must be a function. The action function should either return the new JSON, or a Promise that will resolve the new JSON.

• matcher is a RegExp, and is being tested against asset filenames, that is, the filenames in your build-folder.
• action is a function that receives 2 arguments: json (JSON content of the file), and assetKey (the filename that was matched by the matcher). The function may return the new JSON, or a promise that resolves in the new json.