将所有 class 包裹在 try/catch javascript 中？

Question

如何使用如下方法实现 class？

class ExistingClass {
     function func1() {} // might throw error
     function func2() {} // might throw error
     get try() {
        // Some magic here
        return this; // we need to return this to chain the calls, right? 
     }
}

可以这样称呼

obj.func1() //might throw an error
obj.try.func1() // execute func1 in a try/catch

基本上我想要类似 mochajs 的东西：expect(..).to.not.equal()

更新：接受的答案应该有效，以下是它的更新版本，支持 async 函数

get try() {
    return new Proxy(this, {

        // Intercept method getter
        get: function(target, name) {
            if (typeof target[name] === 'function') {
                if (target[name][Symbol.toStringTag] === 'AsyncFunction') {
                    return async function() {
                        try {
                           await target[name].apply(target, arguments);
                        }
                        catch (e) {}
                    }
                } else {
                    return function() {
                        try {
                            return target[name].apply(target, arguments)
                        }
                        catch (e) {}
                    }
                }
            }
            return target[name];
        }
    });
}

Answer 1

您可以在最新的浏览器中使用代理来执行此操作：

class A {
  method() {
    throw 'Error';
  }

  get try() {
    return new Proxy(this, {
      // Intercept method getter
      get(target, name) {
        if (typeof target[name] === 'function') {
          return new Proxy(target[name], {
            // Intercept method call
            apply(target, self, args) {
              try {
                return target.apply(self, args);
              } catch(e) {
                // swallow error
              }
            }
          })
        }
        return target[name];
      }
    });
  }
}

const a = new A;

a.try.method(); // no error

a.method(); // throws error

Answer 2

的简化版

class A {
  method() {
    throw 'Error';
  }

  get try() {
    return new Proxy(this, {
      // Intercept method getter
      get(target, name) {
        if (typeof target[name] === 'function') {
          return function () {
              try {
                  return target[name].apply(target, arguments)
              } catch (e) {}
          }
        }
        return target[name];
      }
    });
  }
}

const a = new A;

a.try.method(); // no error

a.method(); // throws error

Answer 3

对于不支持 Proxies 的 pre-ES6 浏览器，如果我需要这样的功能，我会这样做：

/* A constructor created the old-fashioned way. */
function ExistingClass () {
  /* The object that will be assigned to this.try. */
  var shadowObj = {};
  
  /* The function that throws an error (calls illegal constructor). */
  this.func1 = function () {
    return new Element();
  };
  
  /* Iterate over every property of the context. */
  for (var func in this) {
    /* Check whether the property is a function. */
    if (this[func] && this[func].constructor == Function) {
      /* Create a shadow function of the context's method. */
      shadowObj[func] = function () {
        try { return this[func]() }
        catch (e) { console.log("Error caught: " + e.message) }
      }.bind(this);
    }
  }
  
  /* Assign the shadow object to this.try. */
  this.try = shadowObj;
}

/* Example. */
var cls = new ExistingClass;
cls.try.func1();
cls.func1();

将所有 class 包裹在 try/catch javascript 中？

Wrap all of your class in try/catch javascript?

javascript

method-chaining