问题
Imagine I have a project like this:
/moduleA/src...
/moduleB/src...
/mainApp/src...
I have a separate webpack.config for each module and the main app. The modules are libraries and the main app imports those libraries.
Is it possible to configure webpack-dev-server to serve all three?
What I want to avoid is having to stop the dev server, rebuild moduleA and moduleB, and restart the dev server, every time I want to make a change to moduleA or B.
回答1:
Not with webpack-dev-server only because that tool is built to watch and serve a single webpack application configuration only.
So the high level answer is: run webpack-dev-server for the application and a watcher for each package dependency, at the same time. A rebuild by one of the watchers will cause a subsequent rebuild of the application by webpack. 
I recommend if you are not already managing your packages within a monorepo that you do so, because it makes this all a little bit less ugly.
Assumptions:
- packages are managed within a monorepo using lerna
 - each package (and the application) has a 
webpack.config.js - you are using Yarn
 
Steps:
for each dependency package, e.g.
moduleA:install cross-env:
yarn add cross-envset up webpack as a watcher in development mode by adding
watchto the config:watch: process.env.NODE_ENV === "development"add an NPM script
"start:dev":"start:dev": "cross-env NODE_ENV=development webpack --config webpack.config.js"
for the application package, e.g.
mainApp:install cross-env:
yarn add cross-envadd an NPM script
"start:dev":"start:dev": "cross-env NODE_ENV=development webpack --config webpack.config.js"
in the monorepo root:
install concurrently
yarn add concurrentlyadd the NPM scripts* for calling the application and each dependency package's
"start:dev"and a"start:dev"which uses them:"watch:app": "cd packages/mainApp && npm run start:dev", "watch:moduleA": "cd packages/moduleA && npm run start:dev", "watch:moduleB": "cd packages/moduleB && npm run start:dev", "start:dev": " concurrently \"npm run watch:app\" \"npm run watch:moduleA\" \"npm run watch:moduleB\" "
Steps to run (in the root of the monorepo):
bootstrap your monorepo with lerna:
lerna bootstrapstart the app dev server and watchers for all of the dependency packages:
npm run start:devnavigate to your application dev server endpoint, e.g.
localhost:8080
___
Addendum: if a monorepo is out of the question, you can look at a combination of using yarn link and an NPM script in your application's package.json that looks something like*:
{
    "start:dev": "
        concurrently
            \"cross-env NODE_ENV=development webpack --config webpack.config.js\" 
            \"cd ./node_modules/moduleA && npm run start:dev\"
            \"cd ./node_modules/moduleB && npm run start:dev\"
     "
}
___
*Note: newlines within NPM scripts are added for readability; you must collapse the newlines if you use these in your package.json. 
来源:https://stackoverflow.com/questions/46444931/how-to-use-webpack-dev-server-with-multiple-webpack-configs