refactor(types): make Snapshot<T> use read-only collections

src/vanilla.ts

@@ -5,8 +5,6 @@ const isObject = (x: unknown): x is object =>
 
 type AnyFunction = (...args: any[]) => any
 
-type AsRef = { $$valtioRef: true }
-
 type ProxyObject = object
 
 type Path = (string | symbol)[]
@@ -25,19 +23,20 @@ type SnapshotIgnore =
   | Set<any>
   | WeakMap<any, any>
   | WeakSet<any>
-  | AsRef
   | Error
   | RegExp
   | AnyFunction
   | Primitive
 
-type Snapshot<T> = T extends SnapshotIgnore
-  ? T
-  : T extends Promise<unknown>
-    ? Awaited<T>
-    : T extends object
-      ? { readonly [K in keyof T]: Snapshot<T[K]> }
-      : T
+type Snapshot<T> = T extends { $$valtioSnapshot: infer S }
+  ? S
+  : T extends SnapshotIgnore
+    ? T
+    : T extends Promise<unknown>
+      ? Awaited<T>
+      : T extends object
+        ? { readonly [K in keyof T]: Snapshot<T[K]> }
+        : T
 
 /**
  * This is not a public API.
@@ -403,9 +402,9 @@ export function snapshot<T extends object>(
   return createSnapshot(target, ensureVersion(), handlePromise) as Snapshot<T>
 }
 
-export function ref<T extends object>(obj: T): T & AsRef {
+export function ref<T extends object>(obj: T) {
   refSet.add(obj)
-  return obj as T & AsRef
+  return obj as T & { $$valtioSnapshot: T }
 }
 
 export const unstable_buildProxyFunction = buildProxyFunction

src/vanilla/utils/proxyMap.ts

@@ -35,9 +35,7 @@ type InternalProxyMap<K, V> = Map<K, V> & {
  * state.set(key, "value")
  * state.get(key) //undefined
  */
-export function proxyMap<K, V>(
-  entries?: Iterable<readonly [K, V]> | null,
-): Map<K, V> {
+export function proxyMap<K, V>(entries?: Iterable<readonly [K, V]> | null) {
   const map: InternalProxyMap<K, V> = proxy({
     data: Array.from(entries || []) as KeyValRecord<K, V>[],
     has(key) {
@@ -107,5 +105,7 @@ export function proxyMap<K, V>(
   })
   Object.seal(map)
 
-  return map as Map<K, V>
+  return map as unknown as Map<K, V> & {
+    $$valtioSnapshot: Omit<Map<K, V>, 'set' | 'delete' | 'clear'>
+  }
 }

src/vanilla/utils/proxySet.ts

@@ -21,7 +21,7 @@ type InternalProxySet<T> = Set<T> & {
  *   set: proxySet()
  * })
  */
-export function proxySet<T>(initialValues?: Iterable<T> | null): Set<T> {
+export function proxySet<T>(initialValues?: Iterable<T> | null) {
   const set: InternalProxySet<T> = proxy({
     data: Array.from(new Set(initialValues)),
     has(value) {
@@ -92,5 +92,7 @@ export function proxySet<T>(initialValues?: Iterable<T> | null): Set<T> {
 
   Object.seal(set)
 
-  return set as Set<T>
+  return set as unknown as Set<T> & {
+    $$valtioSnapshot: Omit<Set<T>, 'add' | 'delete' | 'clear'>
+  }
 }

tests/snapshot.test.ts

@@ -100,9 +100,7 @@ describe('snapsoht typings', () => {
           undefined: undefined
           bool: boolean
           someFunction(): number
-          ref: {
-            $$valtioRef: true
-          }
+          ref: { x: unknown } & { $$valtioSnapshot: { x: unknown } }
         }>,
         {
           readonly string: string
@@ -111,9 +109,7 @@ describe('snapsoht typings', () => {
           readonly undefined: undefined
           readonly bool: boolean
           readonly someFunction: () => number
-          readonly ref: {
-            $$valtioRef: true
-          }
+          readonly ref: { x: unknown }
         }
       >
     >(true)