refactor(build): replace source in environments with separate environmentDefault entry

Replace `source` in environments with separate `environmentDefault` entry and updated docs to reflect this change

BREAKING CHANGE: angular-cli.json has changed. A new `environmentDefault` entry replaces the previous `source` entry inside `environments`.

To migrate the code follow the example below:

Before:

"environments": {
  "source": "environments/environment.ts",
  "dev": "environments/environment.ts",
  "prod": "environments/environment.prod.ts"
}

After:

"environmentSource": "environments/environment.ts",
"environments": {
  "dev": "environments/environment.ts",
  "prod": "environments/environment.prod.ts"
}

Closes angular#3857

Author: jsanchezgarcia

packages/angular-cli/lib/config/schema.d.ts

@@ -12,7 +12,7 @@ export interface CliConfig {
     apps?: {
         root?: string;
         outDir?: string;
-        assets?: string;
+        assets?: string | string[];
         deployUrl?: string;
         index?: string;
         main?: string;
@@ -23,15 +23,21 @@ export interface CliConfig {
         /**
          * Global styles to be included in the build.
          */
-        styles?: string[];
+        styles?: (string | {
+            [name: string]: any;
+            input?: string;
+        })[];
         /**
          * Global scripts to be included in the build.
          */
-        scripts?: string[];
+        scripts?: (string | {
+            [name: string]: any;
+            input?: string;
+        })[];
         /**
          * Environment source file.
          */
-        environmentSource?: string,
+        environmentSource?: string;
         /**
          * Name and corresponding file for environment config.
          */

packages/angular-cli/lib/config/schema.json

@@ -110,6 +110,11 @@
             },
             "additionalProperties": false
           },
+          "environmentSource": {
+            "description": "Environment source file.",
+            "type": "string",
+            "additionalProperties": true
+          },
           "environments": {
             "description": "Name and corresponding file for environment config.",
             "type": "object",

packages/angular-cli/models/webpack-build-common.ts

@@ -102,7 +102,7 @@ export function getWebpackCommonConfig(
 
   // process environment file replacement
   if (appConfig.environments) {
-    if (!('environmentSource' in appConfig.environments)) {
+    if (!(appConfig.environmentSource)) {
       throw new SilentError(`Environment configuration does not contain 
         "environmentSource" entry.`);
     }