cloneClass util prototype done. (#518)

src/clone-class.spec.ts

+#!/usr/bin/env ts-node
+/**
+ *   Wechaty - https://github.com/chatie/wechaty
+ *
+ *   @copyright 2016-2018 Huan LI <zixia@zixia.net>
+ *
+ *   Licensed under the Apache License, Version 2.0 (the "License");
+ *   you may not use this file except in compliance with the License.
+ *   You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *   Unless required by applicable law or agreed to in writing, software
+ *   distributed under the License is distributed on an "AS IS" BASIS,
+ *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *   See the License for the specific language governing permissions and
+ *   limitations under the License.
+ *
+ */
+// tslint:disable:no-shadowed-variable
+import * as test  from 'blue-tape'
+// import * as sinon from 'sinon'
+
+import cloneClass  from './clone-class'
+
+class FixtureClass {
+  public static staticNumber: number
+
+  public static staticMethod(n: number) {
+    this.staticNumber = n
+  }
+
+  constructor(
+    public i: number,
+    public j: number,
+  ) {
+    //
+  }
+
+  public sum() {
+    return this.i + this.j + (this.constructor as any).staticNumber
+  }
+}
+
+const EXPECTED_NUMBER1 = 1
+const EXPECTED_NUMBER2 = 2
+
+test('cloneClass smoke testing', async t => {
+  // tslint:disable-next-line:variable-name
+  const NewClass1 = cloneClass(FixtureClass)
+  // tslint:disable-next-line:variable-name
+  const NewClass2 = cloneClass(FixtureClass)
+
+  t.notEqual(NewClass1, NewClass2,    'NewClass1 should different with NewClass2')
+  t.notEqual(NewClass1, FixtureClass, 'NewClass1 should different with FixtureClass')
+
+  NewClass1.staticMethod(EXPECTED_NUMBER1)
+  t.equal(NewClass1.staticNumber, EXPECTED_NUMBER1, 'should set static number to EXPECTED_NUMBER1')
+
+  NewClass2.staticMethod(EXPECTED_NUMBER2)
+  t.equal(NewClass2.staticNumber, EXPECTED_NUMBER2, 'should set static number to EXPECTED_NUMBER2')
+
+  const nc1 = new NewClass1(EXPECTED_NUMBER1, EXPECTED_NUMBER2)
+  const nc2 = new NewClass2(EXPECTED_NUMBER1, EXPECTED_NUMBER2)
+
+  t.ok(nc1 instanceof FixtureClass, 'nc1 should instanceof FixtureClass')
+  t.ok(nc1 instanceof NewClass1,    'nc1 should  instanceof NewClass1')
+
+  t.equal(nc1.sum(), EXPECTED_NUMBER1 + EXPECTED_NUMBER1 + EXPECTED_NUMBER2, 'should sum right for 1 + 1 + 2')
+  t.equal(nc2.sum(), EXPECTED_NUMBER2 + EXPECTED_NUMBER1 + EXPECTED_NUMBER2, 'should sum right for 2 + 1 + 2')
+})

src/clone-class.ts

+
+/**
+ * Clone Class for easy savig Information into Static Properties
+ * https://github.com/Chatie/wechaty/issues/518
+ */
+
+// https://github.com/Microsoft/TypeScript/issues/10262
+// https://github.com/Microsoft/TypeScript/pull/13743
+type Constructor<T> = new(...args: any[]) => T
+
+// tslint:disable-next-line:variable-name
+export function cloneClass<T extends Constructor<{}>>(OrignalClass: T): T {
+  class NewClass extends OrignalClass {
+    constructor(...args: any[]) {
+      super(...arguments)
+    }
+  }
+  return NewClass as any as T
+}
+
+export default cloneClass