isDraft()

isDraft(value) returns true for a draft, of the current recipe or of any other one, and false for any other value, including the base state, a finished state and the values that a recipe assigned.

isDraft(value: any): boolean

UsageCopy Anchor Link

import { create, isDraft } from 'mutative';

const baseState = {
  date: new Date(),
  list: [{ text: 'todo' }],
};

const state = create(baseState, (draft) => {
  expect(isDraft(draft)).toBe(true);
  expect(isDraft(draft.list)).toBe(true);
  // A Date is not drafted.
  expect(isDraft(draft.date)).toBe(false);
});

expect(isDraft(state)).toBe(false);
expect(isDraft(baseState)).toBe(false);

Use it in helpers that take a draft or a plain value, for example to change a draft in place and to call create() for any other value, as create() on a draft shows. current() and original() throw for values that are not drafts.

isDraft() reads the value, so for a draft whose producer has ended, which Mutative revokes, it throws as any other read does.