There isn't a specific option for environment-specific assets, but you can create different apps in your angular-cli.json file that are essentially duplicates of each other, with varying assets. For example:
// angular-cli.json
"apps": [
{
"root": "src",
"outDir": "dist",
"name": "devApp",
"assets" : [
"assets",
"favicon.ico",
{
"glob": "**/*",
"input": "../externalDir",
"output": "./app/",
"allowOutsideOutDir": true
},
],
...
},
{
"root": "src",
"outDir": "dist",
"name": "prodApp",
"assets": [
"assets",
"favicon.ico"
],
...
}
]
This allows you to build different sets of assets by specifying the desired "app" to build:
// dev
ng build --app=0
// or
ng build --app=devApp
// prod
ng build --app=1
// or
ng build --app=prodApp
For more information on using multiple apps in Angular CLI, refer to the official documentation.