Documentation: need to explain how used vue.config.js in different build modes

What problem does this feature solve?

No any explanation in docs, why in “build --mode development” ignored vue.config.js file. And how developer can build app with bundled assets and enabled vue-dev-tools

What does the proposed API look like?

vue.config.js:

module.exports = {
...
    outputDir: 'dist',
    assetsDir: 'app',
    indexPath: 'app.html',
...
}

Run: # vue-cli-service build --mode development
Result:

/dist
/dist/app.html
/dist/app/js
/dist/app/css
/dist/app/img

[vagrantir]

https://github.com/vagrantir/vue-cli-test node 8, npm 6, win7 I expect that both command build similar ./dist folder, but in –mode development ./dist have plain structure without bundled css/img assets

./node_modules/.bin/vue-cli-service build

./node_modules/.bin/vue-cli-service build --mode development

[vagrantir]

@LinusBorg I found solution for my case by using Vue.config.devtools in main.js and build --mode production, but it`s not clear from documentation/forum/chat. And in this solution need to additional manipulation for enabling sourceMap.

if (process.env.VUE_DEVTOOLS_ENABLED) {
    Vue.config.devtools = true;
}

Why build doesn`t work as “expected” in any mode? As for me, “expected” mean the same output result, which managed by .env variables.

At least, it would be good to explain deeper in documentation, why “bulid --mode modeName” makes different result.