/*保证typescript可以正确计算类型*/export function extend
    
     (target: Type
     
      , source1: Type
      ): Type
       
        ;export function extend
        
         (  target: Type
         
          , source1: Type
          , source2: Type
           
            ): Type
            
             ;export function extend
             
              ( target: Type
              
               , source1: Type
               , source2: Type
                
                 , source3: Type
                 
                  ): Type
                  
                   ;export function extend
                   
                    ( target: Type
                    
                     , source1: Type
                     , source2: Type
                      
                       , source3: Type
                       
                        , source4: Type
                        
                         ): Type
                         
                          ;/*结束*//*功能*/export function extend(target: Type
                          
                           , ...sources: Type
                           
                            []): Type
                            
                              { return extend2(target)(...sources.reverse());}function extend2(target: Type
                             
                              ) { return (...sources: Type
                              
                               []): Type
                               
                                 => { let targetPrototype = target.prototype; // 继承 (function() { // 创建一个干净的实例 function beget() { var F = function() { // sources属性处理 sources.map(source => source.call(this)); }; // sources处理 assign(F.prototype, ...sources.map(source => source.prototype)); return new F(); } let prototype = beget(); prototype.constructor = target; // 继承 target.prototype = prototype; // 原来的方法 assign(target.prototype, targetPrototype); })(); return target as any; };}/*结束*/复制代码
                               
                              
                             
                            
                           
                          
                         
                        
                       
                      
                    
                   
                  
                 
                
              
             
            
           
         
        
       
     
    

测试

import { expect } from "chai";import { extend } from "./extend";export class A {  title: string = "a";  run() {    return "a";  }}export class B {  title: string = "b";  demo: string = "demo";  add() {    return "b";  }}export class D {  title: string = "d";  console() {    return "d";  }}let C = extend(A, B, D);const c = new C();describe("extend", () => {  it("c.demo", () => {    expect(c.demo).equal("demo");  });  it("c.add", () => {    expect(c.add()).equal("b");  });  it("c.add", () => {    expect(c.run()).equal("a");  });  it("c.add", () => {    expect(c.console()).equal("d");  });});复制代码