fix(serve): use proxyConfig option from serve

This option was in the schema because originally `--proxy-config` was an
option provided by the Ionic CLI. Before this change, `proxyConfig` was
overriding the dev-server's `proxyConfig` option, even when undefined.

fixes ionic-team/ionic-cli#3825

builders/cordova-serve/index.ts

@@ -15,16 +15,17 @@ export class CordovaServeBuilder implements Builder<CordovaServeBuilderSchema> {
 
   run(builderConfig: BuilderConfiguration<CordovaServeBuilderSchema>): Observable<BuildEvent> {
     const { options: cordovaServeOptions } = builderConfig;
-    const { devServerTarget, port, host, ssl, proxyConfig } = cordovaServeOptions;
+    const { devServerTarget, port, host, ssl } = cordovaServeOptions;
     const [ project, target, configuration ] = devServerTarget.split(':');
 
-    const devServerTargetSpec = { project, target, configuration, overrides: { port, host, ssl, proxyConfig } };
+    const devServerTargetSpec = { project, target, configuration, overrides: { port, host, ssl } };
     const devServerBuilderConfig = this.context.architect.getBuilderConfiguration<DevServerBuilderOptions>(devServerTargetSpec);
 
     let devServerDescription: BuilderDescription;
     let cordovaBuildConfig: BuilderConfiguration<CordovaBuildBuilderSchema>;
 
-    return this.context.architect.getBuilderDescription(devServerBuilderConfig).pipe(
+    return of(null).pipe(
+      concatMap(() => this.context.architect.getBuilderDescription(devServerBuilderConfig)),
       tap(description => devServerDescription = description),
       concatMap(() => this.context.architect.validateBuilderOptions(devServerBuilderConfig, devServerDescription)),
       concatMap(() => this._getCordovaBuildConfig(cordovaServeOptions)),

builders/cordova-serve/schema.d.ts

@@ -5,7 +5,6 @@ export interface CordovaServeBuilderSchema {
   port?: number;
   host?: string;
   ssl?: boolean;
-  proxyConfig?: string;
   cordovaBasePath?: string;
   sourceMap?: boolean;
 }

builders/cordova-serve/schema.json

@@ -15,10 +15,6 @@
       "type": "string",
       "description": "Cordova platform to use during serve."
     },
-    "proxyConfig": {
-      "type": "string",
-      "description": "Proxy configuration file."
-    },
     "ssl": {
       "type": "boolean",
       "description": "Serve using HTTPS.",