es-toolkit/dist/array/intersectionWith.mjs

A state-of-the-art, high-performance JavaScript utility library with a small bundle size and strong type annotations.

//#region src/array/intersectionWith.ts
/**
* Returns the intersection of two arrays based on a custom equality function.
*
* This function takes two arrays and a custom equality function. It returns a new array containing
* the elements from the first array that have matching elements in the second array, as determined
* by the custom equality function. It effectively filters out any elements from the first array that
* do not have corresponding matches in the second array according to the equality function.
*
* @template T - The type of elements in the first array.
* @template U - The type of elements in the second array.
* @param firstArr - The first array to compare.
* @param secondArr - The second array to compare.
* @param areItemsEqual - A custom function to determine if two elements are equal.
* This function takes two arguments, one from each array, and returns `true` if the elements are considered equal, and `false` otherwise.
* @returns A new array containing the elements from the first array that have corresponding matches in the second array according to the custom equality function.
*
* @example
* const array1 = [{ id: 1 }, { id: 2 }, { id: 3 }];
* const array2 = [{ id: 2 }, { id: 4 }];
* const areItemsEqual = (a, b) => a.id === b.id;
* const result = intersectionWith(array1, array2, areItemsEqual);
* // result will be [{ id: 2 }] since this element has a matching id in both arrays.
*
* @example
* const array1 = [
*   { id: 1, name: 'jane' },
*   { id: 2, name: 'amy' },
*   { id: 3, name: 'michael' },
* ];
* const array2 = [2, 4];
* const areItemsEqual = (a, b) => a.id === b;
* const result = intersectionWith(array1, array2, areItemsEqual);
* // result will be [{ id: 2, name: 'amy' }] since this element has a matching id that is equal to seconds array's element.
*/
function intersectionWith(firstArr, secondArr, areItemsEqual) {
	return firstArr.filter((firstItem) => {
		return secondArr.some((secondItem) => {
			return areItemsEqual(firstItem, secondItem);
		});
	});
}
//#endregion
export { intersectionWith };