JS Fundamentals - Decorators

In this Hasty Treat, Scott and Wes talk about whether decorators are finally here, what the uses cases are for decorators, how to define a decorator, and what auto accessor is. Show Notes 00:25 Welcome 01:00 Are decorators finally here? TC39 proposal

How this compares to other versions of decorators

06:47 What are use cases for decorators? 10:55 How do you define a decorator? 14:20 Auto Accessor on classes @loggged class C {} on fields class C { @logged x = 1; } Auto Accessor class C { accessor x = 1; } sugar for below class C { #x = 1; // # means private get x() { return this.#x; } set x(val) { this.#x = val; } } Can be decorated and decorator can return new get and set and init functions function logged(value, { kind, name }) { if (kind === "accessor") { let { get, set } = value; return { get() { console.log(`getting ${name}`); return get.call(this); }, set(val) { console.log(`setting ${name} to ${val}`); return set.call(this, val); }, init(initialValue) { console.log(`initializing ${name} with value ${initialValue}`); return initialValue; } }; } // ... } Tweet us your tasty treats Scott’s Instagram

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