omit

omit creates a synchronous transform that copies every own enumerable field except selected keys.

import {omit, pipe, rename} from 'shapewire';

const toPublicUser = pipe(
  omit(['password_hash', 'internal_notes']),
  rename({user_id: 'id', full_name: 'name'}),
);

Signature and inference

omit(keys)(input);
omit<Input>()(keys)(input);

Inline arrays infer precise output shapes, readonly arrays are accepted, and the explicit-input form rejects unknown keys at compile time. Optional, readonly, literal, numeric, and symbol fields retain their TypeScript semantics.

Pipelines and ordering

omit can appear before or after pick; every stage receives the previous stage's output:

const toSafeSummary = pipe(
  pick(['id', 'name', 'email', 'token']),
  omit(['token']),
);

Order matters. pipe(pick(['id', 'name']), omit(['name'])) returns only id; a later strongly typed stage cannot use a removed field. If rename runs first, omit the new name rather than the transport name.

Behavior and edge cases

• Returns a new normal plain object, preserves source enumeration order, and never clones then deletes from the input.
• Is shallow and preserves retained values and references exactly, including falsy and nullish values.
• Ignores missing and duplicate omitted keys; inherited and non-enumerable fields are never copied.
• Supports string, numeric, and symbol keys.
• Reads each retained getter once, never reads omitted getters, and stores retained values as data properties.
• Safely handles __proto__, constructor, and prototype without prototype pollution.
• Frozen and sealed inputs are supported.
• The typed API is for object records. At runtime, nullish values and string/number/boolean primitives throw TypeError; arrays and functions are treated as objects.

Use omit when most response fields are useful and a small known set is private or internal. Prefer pick for allowlist-style boundaries. Do not use either transform for deep deletion, validation, asynchronous work, or descriptor-preserving clones.