How to build a production version of React without

问题:

Background

I've been following more or less the official guide to setup a local dev environment with react and it seems to use create-react-app, which sets up really a lot.

Now, if I run npm run build I get a minified version of everything in the build folder. If I, however, run npm start the version NodeJS serves does not seem to have any modifications. But I cannot see these files.

Question

So either:

• Can I access the files generated by npm start somewhere? As these seem to be unmodified. (build is never modified there)
• Or can I somehow run npm run build, so it does a "development" build with unminimized files?

Tries

My aim is just to get access to an unminimized version of react scripts.

As for the last question I've tried some parameters and enironmental variables as suggested in this question, but as you can see, it failed:

$ NODE_ENV=dev npm run build --dev --configuration=dev

> example-project@0.1.0 build [...]
> react-scripts build

Creating an optimized production build...
[...]

System

My package.json has the default scripts:

  "scripts": {
    "start": "react-scripts start",
    "build": "react-scripts build",
    "test": "react-scripts test",
    "eject": "react-scripts eject"
  },

---

Note: Please do not ask why I am doing it or try to convince me that it is bad. There are many reasons why I'd maybe want this, e.g. debugging or this specific use case.

回答1:

To change the webpack config and build scripts you have either to eject from create-react-app (i would not recommend this step, as it breaks future compatibility) or you can use tools like rewire to override some settings

Take a look at this https://github.com/timarney/react-app-rewired

I personally used just rewire

npm i rewire --save-dev

Here is a sample config i created for one of my projects in the past and it worked pretty good!

1. Create a build.js
2. Change your package.json so that it runs build.js

build.js

const rewire = require('rewire');
const defaults = rewire('react-scripts/scripts/build.js');
const config = defaults.__get__('config');

// Consolidate chunk files instead
config.optimization.splitChunks = {
  cacheGroups: {
    default: false,
  },
};
// Move runtime into bundle instead of separate file
config.optimization.runtimeChunk = false;

// JS
config.output.filename = '[name].js';
// CSS. "5" is MiniCssPlugin
config.plugins[5].options.filename = '[name].css';
config.plugins[5].options.publicPath = '../';

Then in my package.json i changed the npm script links like this (node build which will run the build.js script)

package.json

"scripts": {
    "start": "react-scripts start",
    "build": "node build && gulp",
    "test": "react-scripts test",
    "eject": "react-scripts eject"
  },

So if you really want to eject from create-react-app, all you have to do is to run

npm run-script eject

Then you will get a new folder with all configs used by create-react-app

But as i said before, there is no reason why not to use rewire and just override the config instead of ejecting

if it helps, please don't forget to mark as answer Cheers and good success

回答2:

Why can't you see the source files? Here is what I would try:

1. Start your react app with npm run start
2. Open your browser to http://localhost:3000
3. Open Developer tools and inspect the created chunked bundles by the webpack-dev server. In Chrome on a mac, you can do the following: cmd+option+j will open developer tools. Then click the sources tab: within this tab you will see the bundles created by react's build configuration. Now the output of these bundles might not be pretty but it's all there.

Alternatively, all your application's build configuration settings are contained within your webpack.config.js file even when you use create-react-app. As this configuration is just encapsulated within the react-scripts node module. So maybe you could try editing this file directly, without ejecting: <base_path>/node_modules/react-scripts/config/webpack.config.js. Although you need to be careful as to not break an existing configuration setting. You probably want to mess with the source-map settings for production builds. At least this way if you ruin this file you can always just remove and reinstall react-scripts and be back to your initial configuration. This will also allow you to play around with your customizations in 'semi-safe' sandboxed environment. Remember, there is no magic that create-react-app is providing rather it's just making useful defaults for your build configuration.

Lastly, as @xzesstence pointed out you can try out the react-app-rewired module.

Hopefully that helps!