Expose the Shallow type for manual typings

README.md

@@ -47,6 +47,7 @@ Use [Preact signals](https://github.com/preactjs/signals) with the interface of
   - [TypeScript](#typescript)
     - [`DeepSignal`](#deepsignal-1)
     - [`RevertDeepSignal`](#revertdeepsignal)
+    - [`Shallow`](#shallow)
   - [License](#license)
 
 ## Features
@@ -581,6 +582,24 @@ import type { RevertDeepSignal } from "deepsignal";
 const values = Object.values(store as RevertDeepSignal<typeof store>);
 ```
 
+### Shallow
+
+You can use the `Shallow` type if you want to type a store that contains a shallow object.
+
+```ts
+import type { Shallow } from "deepsignal";
+
+type Store = {
+	obj: { a: number };
+	shallowObj: { b: number };
+};
+
+const store = deepSignal<Store>({
+	obj: { a: 1 },
+	shallowObj: shallow({ b: 2 }),
+});
+```
+
 ## License
 
 `MIT`, see the [LICENSE](./LICENSE) file.

packages/deepsignal/core/src/index.ts

@@ -32,9 +32,9 @@ export const peek = <
 };
 
 const isShallow = Symbol("shallow");
-export function shallow<T extends object>(obj: T): T & { [isShallow]: true } {
+export function shallow<T extends object>(obj: T): Shallow<T> {
 	ignore.add(obj);
-	return obj as T & { [isShallow]: true };
+	return obj as Shallow<T>;
 }
 
 const createProxy = (target: object, handlers: ProxyHandler<object>) => {
@@ -277,6 +277,8 @@ type DeepSignalArray<T> = DeepArray<ArrayType<T>> & {
 	$length?: Signal<number>;
 };
 
+export type Shallow<T extends object> = T & { [isShallow]: true };
+
 export declare const useDeepSignal: <T extends object>(obj: T) => DeepSignal<T>;
 
 type FilterSignals<K> = K extends `$${infer P}` ? never : K;

packages/deepsignal/core/test/types.ts

@@ -89,3 +89,20 @@ store3.a = { b: 1 };
 // @ts-expect-error
 store3.c = { b: 2 };
 store3.c = shallow({ b: 2 });
+
+type Store4 = {
+	a: { b: number };
+	c: Shallow<{ b: number }>;
+	d: Shallow<{ b: number }>;
+};
+
+const store4 = deepSignal<Store4>({
+	a: { b: 1 },
+	c: shallow({ b: 2 }),
+	// @ts-expect-error
+	d: { b: 3 },
+});
+
+store4.a.$b;
+// @ts-expect-error
+store4.c.$b;