@statesync/jotai

---

@statesync/jotai / JotaiSnapshotApplierOptions

Type Alias: JotaiSnapshotApplierOptions<State, Data>

type JotaiSnapshotApplierOptions<State, Data> = 
  | {
  mode?: "patch";
  omitKeys?: ReadonlyArray<keyof State>;
  pickKeys?: ReadonlyArray<keyof State>;
  strict?: boolean;
  toState?: (data, ctx) => Partial<State>;
}
  | {
  mode: "replace";
  omitKeys?: ReadonlyArray<keyof State>;
  pickKeys?: ReadonlyArray<keyof State>;
  strict?: boolean;
  toState?: (data, ctx) => State;
};

Defined in: jotai.ts:80

Configuration options for createJotaiSnapshotApplier.

This is a discriminated union on the mode field:

• When mode is 'patch' (or omitted), toState is expected to return Partial<State>.
• When mode is 'replace', toState is expected to return the full State.

Type Parameters

Type Parameter	Description
State extends Record<string, unknown>	The value type of the atom.
Data	The snapshot payload type received from the sync engine. Defaults to State when the snapshot data matches the atom value shape directly.

Type Declaration

{
  mode?: "patch";
  omitKeys?: ReadonlyArray<keyof State>;
  pickKeys?: ReadonlyArray<keyof State>;
  strict?: boolean;
  toState?: (data, ctx) => Partial<State>;
}

mode?

optional mode: "patch";

The apply strategy. Defaults to 'patch'.

Default Value

'patch'

omitKeys?

optional omitKeys: ReadonlyArray<keyof State>;

pickKeys?

optional pickKeys: ReadonlyArray<keyof State>;

strict?

optional strict: boolean;

When true, the applier throws if toState returns a non-plain-object value. When false, such values are silently ignored.

Default Value

true

toState()?

optional toState: (data, ctx) => Partial<State>;

Maps raw snapshot data to a state patch object.

Parameters

Parameter	Type	Description
data	Data	The raw snapshot payload from the sync engine.
ctx	{ atom: unknown; store: JotaiStoreLike<State, unknown>; }	Context object providing access to the target store and atom.
ctx.atom	unknown	-
ctx.store	JotaiStoreLike<State, unknown>	-

Returns

Partial<State>

A partial state object to be shallow-merged into the atom.

Default Value

Identity cast — treats data as Partial<State>.

{
  mode: "replace";
  omitKeys?: ReadonlyArray<keyof State>;
  pickKeys?: ReadonlyArray<keyof State>;
  strict?: boolean;
  toState?: (data, ctx) => State;
}

mode

mode: "replace";

Use 'replace' mode for an atomic full-state swap.

omitKeys?

optional omitKeys: ReadonlyArray<keyof State>;

pickKeys?

optional pickKeys: ReadonlyArray<keyof State>;

strict?

optional strict: boolean;

When true, the applier throws if toState returns a non-plain-object value. When false, such values are silently ignored.

Default Value

true

toState()?

optional toState: (data, ctx) => State;

Maps raw snapshot data to the full next state.

Parameters

Parameter	Type	Description
data	Data	The raw snapshot payload from the sync engine.
ctx	{ atom: unknown; store: JotaiStoreLike<State, unknown>; }	Context object providing access to the target store and atom.
ctx.atom	unknown	-
ctx.store	JotaiStoreLike<State, unknown>	-

Returns

State

The full next state to replace the current atom value with.

Default Value

Identity cast — treats data as State.