Add observer lifecycle regression tests

Author: fatbobman

Tests/ObservableDefaultsMacroTests/MacroStructureTests.swift

@@ -18,6 +18,9 @@ struct MacroStructureTests {
         let classes = tree.statements.compactMap { $0.item.as(ClassDeclSyntax.self) }
         #expect(classes.count == 1)
         #expect(classes.first?.name.text == "DefaultsBasicFixture")
+        #expect(result.expandedSource.contains("private var notificationObserver: NSObjectProtocol?"))
+        #expect(result.expandedSource.contains("NotificationCenter.default.removeObserver(observer)"))
+        #expect(!result.expandedSource.contains("NotificationCenter.default.removeObserver(self)"))
     }
 
     @Test("ObserveFirst defaults only maps explicitly backed properties")
@@ -42,6 +45,9 @@ struct MacroStructureTests {
         #expect(result.expandedSource.contains("var _ephemeral: String = \"scratch\""))
         #expect(result.expandedSource.contains(#"case prefix + "theme":"#))
         #expect(!result.expandedSource.contains(#"case prefix + "ephemeral":"#))
+        #expect(result.expandedSource.contains("private var notificationObserver: NSObjectProtocol?"))
+        #expect(result.expandedSource.contains("NotificationCenter.default.removeObserver(observer)"))
+        #expect(!result.expandedSource.contains("NotificationCenter.default.removeObserver(self)"))
     }
 
     @Test("defaultIsolationIsMainActor adds MainActor-specific generated code for defaults")

Tests/ObservableDefaultsTests/ObservableCloudTests.swift

@@ -92,6 +92,19 @@ struct ObservableCloudTests {
             #expect(userDefaults.string(forKey: "test_name") == "Test2")
         }
 
+        @Test("Model with cloud observer infrastructure deallocates", .testMode)
+        func cloudObserverInfrastructureDeallocates() {
+            weak var weakModel: MockModelCloud?
+
+            do {
+                let model = MockModelCloud(developmentMode: false)
+                weakModel = model
+                #expect(weakModel != nil)
+            }
+
+            #expect(weakModel == nil)
+        }
+
         @Test("syncImmediately macro default is preserved by generated init", .testMode)
         func syncImmediatelyMacroDefaultIsPreserved() {
             let model = MockModelCloudSyncImmediately()

Tests/ObservableDefaultsTests/ObservableDefaultsTests.swift

@@ -79,6 +79,20 @@ struct ObservableDefaultsTests {
         #expect(model.name == "Test1", "name should be observable by setting value by UserDefaults")
     }
 
+    @Test("Model with defaults observer infrastructure deallocates")
+    func defaultsObserverInfrastructureDeallocates() {
+        let userDefaults = UserDefaults.getTestInstance(suiteName: #function)
+        weak var weakModel: MockModel?
+
+        do {
+            let model = MockModel(userDefaults: userDefaults)
+            weakModel = model
+            #expect(weakModel != nil)
+        }
+
+        #expect(weakModel == nil)
+    }
+
     @Test("Observable Only")
     func observableOnly() {
         let userDefaults = UserDefaults.getTestInstance(suiteName: #function)