Update vue-cli mode documentation to show a mode other than production or development

What problem does this feature solve?

Increases comprehension on what the --mode feature can be used for and how it might be used, specifically that you can override the NODE_ENV variable to produce a production build with alternate config (ie. staging)

Refer to https://forum.vuejs.org/t/how-to-build-production-app-with-varying-config/29708/3

What does the proposed API look like?

.env
VUE_APP_TITLE=My App

.env.staging
NODE_ENV=production
VUE_APP_TITLE=My App (staging)

vue-cli-service build

• builds a production app using .env then .env.production (or .env.production.local)

vue-cli-service build --mode staging

• builds a production app using .env then .env.staging (or .env.staging.local)

In both cases, the app is built as a production app because of the NODE_ENV, but in the staging equivalent the process.env.VUE_APP_TITLE variable is overrided

[richard-edwards]

@jnarowski See the start of this thread, just add a ‘.env.staging’ file and add the NODE_ENV=production as the first line and then do vue-cli-service build --mode staging

[chriszrc]

Hmm, I’m wondering if the example of setting the BASE_URL on this page should also be updated:

https://cli.vuejs.org/config/#baseurl

Because if the only way to trigger a slimmed down “production” build is by setting the NODE_ENV=production, it makes relying on the NODE_ENV to inform the app about which environment you’re in useless.

Instead, it seems like the example here should instead rely on using the modes, and setting the different base_urls in an environment variable in the corresponding .env.[mode] file and using that variable to set the baseUrl: value:

baseUrl: process.env.BASE_URL_PREFIX,