fix(@angular/cli): Resolve interface type anonymous option

Author: Brocco

packages/@angular/cli/commands/generate.ts

@@ -102,13 +102,20 @@ export default Command.extend({
       ui: this.ui,
       project: this.project
     });
+    const collectionName = this.getCollectionName(rawArgs);
 
     return getOptionsTask.run({
         schematicName,
-        collectionName: this.getCollectionName(rawArgs)
+        collectionName
       })
       .then((availableOptions: SchematicAvailableOptions) => {
+        let anonymousOptions: string[] = [];
+        if (collectionName === '@schematics/angular' && schematicName === 'interface') {
+          anonymousOptions = ['<type>'];
+        }
+
         this.registerOptions({
+          anonymousOptions: anonymousOptions,
           availableOptions: availableOptions
         });
       });
@@ -143,11 +150,16 @@ export default Command.extend({
       ui: this.ui,
       project: this.project
     });
+    const collectionName = this.getCollectionName(rawArgs);
+
+    if (collectionName === '@schematics/angular' && schematicName === 'interface' && rawArgs[2]) {
+      commandOptions.type = rawArgs[2];
+    }
 
     return schematicRunTask.run({
         taskOptions: commandOptions,
         workingDir: cwd,
-        collectionName: this.getCollectionName(rawArgs),
+        collectionName,
         schematicName
       });
   },