Add purgeStorage to InMemoryStorage

Sources/Sharing/SharedKeys/InMemoryKey.swift

@@ -30,8 +30,8 @@ extension SharedReaderKey {
 ///
 /// See ``SharedReaderKey/inMemory(_:)`` to create values of this type.
 public struct InMemoryKey<Value: Sendable>: SharedKey {
-  private let key: String
   private let store: InMemoryStorage
+  fileprivate let key: String
   fileprivate init(_ key: String) {
     @Dependency(\.defaultInMemoryStorage) var defaultInMemoryStorage
     self.key = key
@@ -80,6 +80,15 @@ public struct InMemoryStorage: Hashable, Sendable {
   public func hash(into hasher: inout Hasher) {
     hasher.combine(id)
   }
+//  public func removeValue(for key: String) {
+//    removeValue(for: )
+//  }
+  public func removeValue<Value>(for key: InMemoryKey<Value>, default defaultValue: Value) {
+    values.removeValue(for: key, default: defaultValue)
+  }
+  public func removeValue<Value>(for key: InMemoryKey<Value>.Default) {
+    removeValue(for: key.base, default: key.initialValue)
+  }
   fileprivate final class Values: Sendable {
     let storage = Mutex<[String: any Sendable]>([:])
 
@@ -99,6 +108,18 @@ public struct InMemoryStorage: Hashable, Sendable {
         }
       }
     }
+
+    func removeValue<Value>(for key: InMemoryKey<Value>, default defaultValue: Value) {
+      @Dependency(PersistentReferences.self) var persistentReferences
+      let reference = persistentReferences.value(
+        forKey: .inMemory(key.key),
+        default: defaultValue,
+        skipInitialLoad: false
+      )
+      reference.withLock { value in
+        value = defaultValue
+      }
+    }
   }
 }
 

Tests/SharingTests/InMemoryTests.swift

@@ -22,6 +22,30 @@ import Testing
     #expect(count == 2)
   }
 
+  @Test func removeValue() async {
+    @Dependency(\.defaultInMemoryStorage) var storage
+
+    do {
+      @Shared(.inMemory("count")) var count = 0
+
+      #expect(count == 0)
+
+      $count.withLock { $0 += 1 }
+
+      #expect(count == 1)
+    }
+
+    do {
+      @Shared(.inMemory("count")) var count = 0
+
+      #expect(count == 1)
+
+      storage.removeValue(for: InMemoryKey<Int>.inMemory("count"), default: 0)
+
+      #expect(count == 0)
+    }
+  }
+
   @Test func referenceCounting() async throws {
     do {
       @Shared(.inMemory("count")) var count = 0

Tests/SharingTests/ObservationTests.swift

@@ -1,3 +1,4 @@
+import Dependencies
 import PerceptionCore
 import Sharing
 import Testing
@@ -29,4 +30,30 @@ import Testing
       $count.withLock { $0 += 1 }
     }
   }
+
+  @Test func removeValueShared() async {
+    @Dependency(\.defaultInMemoryStorage) var storage
+    @Shared(.inMemory("count")) var count = 0
+    await confirmation { confirm in
+      withPerceptionTracking {
+        _ = count
+      } onChange: {
+        confirm()
+      }
+      storage.removeValue(for: InMemoryKey<Int>.inMemory("count"), default: 0)
+    }
+  }
+
+  @Test func removeValueSharedReader() async {
+    @Dependency(\.defaultInMemoryStorage) var storage
+    @SharedReader(.inMemory("count")) var count = 0
+    await confirmation { confirm in
+      withPerceptionTracking {
+        _ = count
+      } onChange: {
+        confirm()
+      }
+      storage.removeValue(for: InMemoryKey<Int>.inMemory("count"), default: 0)
+    }
+  }
 }