ra-core/src/util/shallowEqual.ts

Core components of react-admin, a frontend Framework for building admin applications on top of REST services, using ES6, React

function is(x: unknown, y: unknown) {
    if (x === y) {
        return x !== 0 || y !== 0 || 1 / x === 1 / y;
    } else {
        return x !== x && y !== y;
    }
}

export const shallowEqual = (objA: any, objB: any) => {
    if (is(objA, objB)) return true;

    if (
        typeof objA !== 'object' ||
        objA === null ||
        typeof objB !== 'object' ||
        objB === null
    ) {
        return false;
    }

    const keysA = Object.keys(objA);
    const keysB = Object.keys(objB);

    if (keysA.length !== keysB.length) return false;

    for (let i = 0; i < keysA.length; i++) {
        if (
            !Object.prototype.hasOwnProperty.call(objB, keysA[i]) ||
            !is(objA[keysA[i]], objB[keysA[i]])
        ) {
            return false;
        }
    }

    return true;
};