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Merging objects with Partial type

lacolaco profile image Suguru Inatomi ・1 min read

My usual implementation pattern of immutable merging in TypeScript.

class MyClass {
    constructor(public id: string, public name: string) {}

    clone() {
        return new MyClass(this.id, this.name);
    }

    merge(another: Partial<MyClass>) {
        return Object.assign(this.clone(), another);
    }
}

const objA = new MyClass("1", "foo");

const objB = objA.merge({ name: "bar" });

console.log(objA !== objB);
console.log(objB.id === "1");
console.log(objB.name === "bar");

Partial<MyClass> allows us to pass an object matching MyClass partially.

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