feat(@schematics/angular): Add interface schematic

Author: jschwarty

packages/schematics/angular/collection.json

@@ -20,6 +20,11 @@
       "description": "Create an enumeration.",
       "schema": "./enum/schema.json"
     },
+    "interface": {
+      "factory": "./interface",
+      "description": "Create an interface.",
+      "schema": "./interface/schema.json"
+    },
     "module": {
       "factory": "./module",
       "description": "Create an Angular module.",

packages/schematics/angular/interface/files/__path__/__name@dasherize____type__.ts

@@ -0,0 +1,2 @@
+export interface <%= prefix %><%= classify(name) %> {
+}

packages/schematics/angular/interface/index.ts

@@ -0,0 +1,40 @@
+/**
+ * @license
+ * Copyright Google Inc. All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+// TODO: replace `options: any` with an actual type generated from the schema.
+// tslint:disable:no-any
+import {
+  Rule,
+  apply,
+  branchAndMerge,
+  chain,
+  mergeWith,
+  move,
+  template,
+  url,
+} from '@angular-devkit/schematics';
+import * as stringUtils from '../strings';
+
+
+export default function (options: any): Rule {
+  options.prefix = options.prefix ? options.prefix : '';
+  options.type = !!options.type ? `.${options.type}` : '';
+
+  const templateSource = apply(url('./files'), [
+    template({
+      ...stringUtils,
+      ...options,
+    }),
+    move(options.sourceDir),
+  ]);
+
+  return chain([
+    branchAndMerge(chain([
+      mergeWith(templateSource),
+    ])),
+  ]);
+}

packages/schematics/angular/interface/schema.json

@@ -0,0 +1,32 @@
+{
+  "$schema": "http://json-schema.org/schema",
+  "id": "SchematicsAngularInterface",
+  "title": "Angular Interface Options Schema",
+  "type": "object",
+  "properties": {
+    "name": {
+      "type": "string"
+    },
+    "path": {
+      "type": "string",
+      "default": "app"
+    },
+    "sourceDir": {
+      "type": "string",
+      "default": "src"
+    },
+    "prefix": {
+      "type": "string",
+      "default": "",
+      "description": "Specifies the prefix to use."
+    },
+    "type": {
+      "type": "string",
+      "description": "Specifies the type of interface.",
+      "default": ""
+    }
+  },
+  "required": [
+    "name"
+  ]
+}