For AI agents: the complete documentation index is available at /llms.txt, the full documentation bundle is available at /llms-full.txt, and this page is available as Markdown at /reference/fp/uniqWith.md.
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    uniqWith (Functional Programming) es-toolkit

    Creates a function that removes duplicates using a custom equality function. Use it with pipe.

    const result = pipe(array, uniqWith(areItemsEqual));
    Info

    Prefer the original es-toolkit uniqWith in ordinary code. Use this fp variant when composing transformations with pipe.

    Usage

    uniqWith keeps the first value that does not match a previously kept value according to areItemsEqual. It is lazy-capable inside pipe.

    import { pipe, uniqWith } from 'es-toolkit/fp';

pipe(
  [{ id: 1 }, { id: 1 }, { id: 2 }],
  uniqWith((a, b) => a.id === b.id)
); // => [{ id: 1 }, { id: 2 }]

    Parameters

    areItemsEqual(item: T, other: T) => booleanrequired

    The function that decides whether two values are equal.

    Returns

    A function that maps a readonly T[] to a duplicate-free array by custom equality.

    (array: readonly T[]) => T[]
    Source: es-toolkit

    Re-exported verbatim from es-toolkit. Implementation, edge cases, and performance behavior are owned upstream. This page mirrors the documentation at the pinned version; the linked source is authoritative.