Angular 2 with CLI - build for production

Question

I have freshly installed angular-cli 1.0.0.beta.17 (latest one), start new project, able to serve project on port 4200 with no problems - just standard "app works!" message.

However when I try to build for production this empty and generic application by using command ng build --prod I do not have main.*.js file created at all and have a few screens of warnings like:

• Dropping unused function...
• Site effects in initialization...
• etc

This is a brand new empty project - I did not have a chance to break anything yet...

How to build production version ?

Answer 1

Updated for Angular v6+

# Prod - these are equivalent
ng build --configuration=production
ng build --c=production
ng build --prod=true

# Dev - and so are these
ng build --configuration=development
ng build --c=development
ng build --prod=false
ng build

More flag settings here

https://angular.io/cli/build

---

Per Angular-cli's github wiki v2+, these are the most common ways to initiate a dev and production build

# Prod these are equivalent
ng build --target=production --environment=prod
ng build --prod --env=prod
ng build --prod

# Dev and so are these
ng build --target=development --environment=dev
ng build --dev --env=dev
ng build --dev
ng build

There are different default flags that will affect --dev vs --prod builds.

Flag                 --dev      --prod
--aot                false      true
--environment        dev        prod
--output-hashing     media      all
--sourcemaps         true       false
--extract-css        false      true

--prod also sets the following non-flaggable settings:

• Adds service worker if configured in .angular-cli.json.
• Replaces process.env.NODE_ENV in modules with the production value (this is needed for some libraries, like react).
• Runs UglifyJS on the code.

---

I need to do some troubleshooting in order to get AOT working. When I ran:

ng build --prod --aot=false

I would get will return a error similar to

Module not found: Error: Can't resolve './$$_gendir/app/app.module.ngfactory'

Originally, I had to do some project refactoring to get AOT to work. However, they may be a fix if you are encountering this error. Try

npm i [email protected]

https://github.com/angular/angular-cli/issues/7113