55 lines
1.2 KiB
TypeScript
55 lines
1.2 KiB
TypeScript
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// Class decorator
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function seal(constructor: Function) {
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Object.seal(constructor);
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Object.seal(constructor.prototype);
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}
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// Method decorator
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function setTimeout(ms = 0) { // Notice the wrapper function to get arguments, this can be done to any decorator function
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return function(target: any, propertyKey: string, descriptor: PropertyDescriptor) {
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const originalMethod = descriptor.value;
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descriptor.value = function () {
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setTimeout(() => originalMethod.apply(this, arguments), ms);
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};
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return descriptor;
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}
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}
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// Accessor/Property decorator
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function log(target: any, key: string) {
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let value = target[key];
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Object.defineProperty(target, key, {
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get: () => {
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console.log(`Get => ${key}`);
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return value;
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},
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set: (newValue) => {
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console.log(`Set: ${key} => ${e}`);
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value = newValue;
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},
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enumerable: true,
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configurable: true
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});
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}
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// Example
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@seal
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class Person {
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@log firstName: string;
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@log lastName: string;
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@log
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get name() { return `${this.firstName} ${this.lastName}`};
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constructor(firstName: string, lastName: string) {
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this.firstName = firstName;
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this.lastName = lastName;
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}
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@timeout(1000)
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whoami() {
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return this.name;
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}
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}
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