A JavaScript hook/reply ultility
此腳本不應該直接安裝，它是一個供其他腳本使用的函式庫。欲使用本函式庫，請在腳本 metadata 寫上： // @require https://update.greasyfork.org/scripts/18715/661566/Hooks.js
// ==UserScript==
// @name Hooks
// @namespace xuyiming.open@outlook.com
// @description A JavaScript hook/reply ultility
// @author xymopen
// @version 1.1.5
// @grant none
// @license BSD 2-Clause
// ==/UserScript==
// @updateURL https://raw.githubusercontent.com/xymopen/JS_Misc/master/Hooks.js
// I was finishing unit test and found there are some bugs about the logic
/**
* Hooks functions or properties, getters/setters
* and methods of an object you are intrested in
*/
var Hooks = ( function () {
"use strict";
var Functions = {
/**
* wrapper a function
* @param {Function} target
* @param {(Function, Object?, Arguments) => void} onApply
*/
apply: function apply( target, onApply ) {
if ( "function" === typeof target && "function" === typeof onApply ) {
var fn = function () {
return onApply.call( this, target, this, arguments );
};
fn.prototype = target.prototype;
return fn;
} else {
throw new TypeError();
}
}
};
/**
* Hooks functions or properties, getters/setters
* and methods of an object you are intrested in
*/
var Hooks = {
/**
* hook a property of an object
* @param {Object} target - an object having or to have the property to be hooked
* @param {String} propertyName - the name of the property to be hooked
* @param {Function} onGet - the hook call when about to get the property
* @param {Function} onSet - the hook call when about to set the property
*/
property: function property( target, propertyName, onGet, onSet ) {
var descriptor, oldValue;
if ( Object.prototype.hasOwnProperty.call( target, propertyName ) ) {
descriptor = Object.getOwnPropertyDescriptor( target, propertyName );
if ( Object.prototype.hasOwnProperty.call( descriptor, "value" ) ) {
oldValue = descriptor.value;
delete descriptor.value;
delete descriptor.writable;
} else if ( Object.prototype.hasOwnProperty.call( descriptor, "get" ) ) {
oldValue = descriptor.get.call( target );
} else {
oldValue = undefined;
}
} else {
descriptor = {
configurable: true,
enumerable: true,
};
oldValue = undefined;
}
descriptor.get = function get() {
return onGet.call( this, target, propertyName, oldValue );
};
descriptor.set = function set( newValue ) {
oldValue = onSet.call( this, target, propertyName, oldValue, newValue );
};
Object.defineProperty( target, propertyName, descriptor );
},
/**
* the hook call when about to get the property
* @callback onGet
* @param {object} target - the object having the property hooked
* @param {string} propertyName - the name of the property hooked
* @param {any} oldValue - the current value of the property
*/
/**
* the hook call when about to set the property
* @callback onSet
* @param {object} target - the object having the property hooked
* @param {string} propertyName - the name of the property hooked
* @param {any} oldValue - the current value of the property
* @param {any} newValue - the value about to be set to the property
*/
/**
* alias of #property but fill the #onSet automatically
* @function get
* @param {Object} target - an object having or to have the property to be hooked
* @param {String} propertyName - he name of the property to be hooked
* @param {onGet} onGet - the hook call when about to get the property
*/
get: function get( target, propertyName, onGet ) {
return Hooks.property( target, propertyName, onGet, function ( target, propertyName, oldValue, newValue ) {
return Hooks.Reply.set( arguments );
} );
},
/**
* alias of #property but fill the #onGet automatically
* @function set
* @param {Object} target - an object having or to have the property to be hooked
* @param {String} propertyName - the name of the property to be hooked
* @param {onSet} onSet - the hook call when about to set the property
*/
set: function set( target, propertyName, onSet ) {
return Hooks.property( target, propertyName, function ( target, propertyName, oldValue ) {
return Hooks.Reply.get( arguments );
}, onSet );
},
/**
* hook a getter property of an object
* @function getter
* @param {object} target - an object having the getter property to be hooked
* @param {string} propertyName - the name of the getter property to be hooked
* @param {onGetter} onGetter - the hook replace the getter
*/
getter: function getter( target, propertyName, onGetter ) {
var descriptor;
if ( Object.prototype.hasOwnProperty.call( target, propertyName ) ) {
descriptor = Object.getOwnPropertyDescriptor( target, propertyName );
if ( Object.prototype.hasOwnProperty.call( descriptor, "get" ) ) {
descriptor.get = Functions.apply( descriptor.get, function ( getter, thisArg, args ) {
return onGetter.call( this, target, propertyName, getter, thisArg, args );
} );
Object.defineProperty( target, propertyName, descriptor );
}
}
},
/**
* the hook replace the getter
* @callback onSetter
* @param {object} target - the object having the getter property hooked
* @param {string} propertyName - he name of the getter property hooked
* @param {function} getter - the getter replaced
* @param {object|undefined} thisArg - #this reference
* @param {arguments} args - the arguments pass to the getter, should be #undefined
*/
/**
* hook a setter property of an object
* @function setter
* @param {object} target - an object having the setter property to be hooked
* @param {string} propertyName - the name of the setter property to be hooked
* @param {onSetter} onSetter - the hook replace the setter
*/
setter: function setter( target, propertyName, onSetter ) {
var descriptor;
if ( Object.prototype.hasOwnProperty.call( target, propertyName ) ) {
descriptor = Object.getOwnPropertyDescriptor( target, propertyName );
if ( Object.prototype.hasOwnProperty.call( descriptor, "set" ) ) {
descriptor.set = Functions.apply( descriptor.set, function ( setter, thisArg, args ) {
onSetter.call( this, target, propertyName, setter, thisArg, args );
} );
Object.defineProperty( target, propertyName, descriptor );
}
}
},
/**
* the hook replace the setter
* @callback onSetter
* @param {object} target - the object having the setter property hooked
* @param {string} propertyName - he name of the setter property hooked
* @param {function} setter - the setter replaced
* @param {object|undefined} thisArg - #this reference
* @param {arguments} args - the arguments pass to the setter, should be a right value
*/
/**
* hook a method of an object
* @function method
* @param {object} target - an object having or to have the method to be hooked
* @param {string} methodName - the name of the method to be hooked
* @param {onApply} onApply - the hook replace the method
*/
method: function method( target, methodName, onApply ) {
var method = target[ methodName ];
function hook( method ) {
return Functions.apply( method, function ( method, thisArg, args ) {
return onApply.call( this, target, methodName, method, thisArg, args );
} );
};
if ( "function" === typeof method ) {
target[ methodName ] = hook( method );
} else if ( !Object.prototype.hasOwnProperty.call( target, methodName ) ) {
Object.defineProperty( target, methodName, {
configurable: true,
enumerable: true,
set: function ( value ) {
Object.defineProperty( target, methodName, {
configurable: true,
enumerable: true,
value: typeof value === "function" ? hook( value ) : value,
writable: true
} );
},
get: function () {
return undefined;
}
} );
}
},
/**
* the hook replace the method
* @callback onApply
* @param {object} target - the object having the method hooked
* @param {string} methodName - the name of the method hooked
* @param {object|undefined} thisArg - #this reference
* @param {arguments} args - the arguments pass to the method
*/
};
Hooks.Reply = {
get: function ( param ) {
var target = param[ 0 ],
propertyName = param[ 1 ],
oldValue = param[ 2 ];
return oldValue;
},
set: function ( param ) {
var target = param[ 0 ],
propertyName = param[ 1 ],
oldValue = param[ 2 ],
newValue = param[ 3 ];
return newValue;
},
getter: function ( param ) {
var target = param[ 0 ],
propertyName = param[ 1 ],
getter = param[ 2 ],
thisArg = param[ 3 ],
args = param[ 4 ];
return getter.apply( thisArg, args );
},
setter: function ( param ) {
var target = param[ 0 ],
propertyName = param[ 1 ],
setter = param[ 2 ],
thisArg = param[ 3 ],
args = param[ 4 ];
setter.apply( thisArg, args );
},
method: function method( param ) {
var target = param[ 0 ],
methodName = param[ 1 ],
method = param[ 2 ],
thisArg = param[ 3 ],
args = param[ 4 ];
return method.apply( thisArg, args );
},
};
return Hooks;
} )();