unionBy

Import from @varavel/vdl-plugin-sdk/utils/arrays.

function unionBy<T, U>(
   arr1, 
   arr2, 
   mapper
): T[];

Creates an array of unique values, in order, from all given arrays using a provided mapping function to determine equality.

Type Parameters

Type Parameter	Description
`T`	The type of elements in the array.
`U`	The type of mapped elements.

Parameters

Parameter	Type	Description
`arr1`	readonly `T`[]	The first array.
`arr2`	readonly `T`[]	The second array.
`mapper`	(`item`) => `U`	The function to map array elements to comparison values.

Returns

T[]

A new array containing the union of unique elements from arr1 and arr2, based on the values returned by the mapping function.

Examples

// Custom mapping function for numbers (modulo comparison)
const moduloMapper = (x) => x % 3;
unionBy([1, 2, 3], [4, 5, 6], moduloMapper);
// Returns [1, 2, 3]

// Custom mapping function for objects with an 'id' property
const idMapper = (obj) => obj.id;
unionBy([{ id: 1 }, { id: 2 }], [{ id: 2 }, { id: 3 }], idMapper);
// Returns [{ id: 1 }, { id: 2 }, { id: 3 }]