Add optional ignoreIfNotRegistered to unregister #420

lib/get_it.dart

@@ -801,11 +801,14 @@ abstract class GetIt {
   /// if referenceCount is 0
   /// [ignoreReferenceCount] if `true` it will ignore the reference count and unregister the object
   /// only use this if you know what you are doing
+  /// [ignoreIfNotRegistered] if `true` a missing registration is a no-op instead of
+  /// throwing. Defaults to `false` so a second dispose still surfaces a logic error.
   FutureOr unregister<T extends Object>({
     Object? instance,
     String? instanceName,
     FutureOr Function(T)? disposingFunction,
     bool ignoreReferenceCount = false,
+    bool ignoreIfNotRegistered = false,
   });
 
   /// returns a Future that completes if all asynchronously created Singletons and any

lib/get_it_impl.dart

@@ -1414,17 +1414,31 @@ class _GetItImplementation implements GetIt {
   /// If you have provided an disposing function when you registered the object that one will be called automatically
   /// If you have enabled reference counting when registering, [unregister] will only unregister and dispose the object
   /// if referenceCount is 0
+  /// [ignoreIfNotRegistered] if `true` a missing registration is a no-op instead of
+  /// throwing. Defaults to `false`.
   ///
   @override
   FutureOr unregister<T extends Object>({
     Object? instance,
     String? instanceName,
     FutureOr Function(T)? disposingFunction,
     bool ignoreReferenceCount = false,
+    bool ignoreIfNotRegistered = false,
   }) async {
-    final registrationToRemove = instance != null
-        ? _findRegistrationByInstance(instance)
-        : _findRegistrationByNameAndType<T>(instanceName);
+    final _ObjectRegistration? registrationToRemove;
+    if (instance != null) {
+      registrationToRemove = ignoreIfNotRegistered
+          ? _findFirstRegistrationByInstanceOrNull(instance)
+          : _findRegistrationByInstance(instance);
+    } else {
+      registrationToRemove = ignoreIfNotRegistered
+          ? _findFirstRegistrationByNameAndTypeOrNull<T>(instanceName)
+          : _findRegistrationByNameAndType<T>(instanceName);
+    }
+
+    if (registrationToRemove == null) {
+      return;
+    }
 
     throwIf(
       registrationToRemove.objectsWaiting.isNotEmpty,

test/get_it_test.dart

@@ -1151,6 +1151,60 @@ void main() {
       throwsStateError,
     );
   });
+
+  test('unregister throws by default if not registered', () async {
+    final getIt = GetIt.instance;
+
+    await expectLater(getIt.unregister<TestClass>(), throwsStateError);
+
+    getIt.registerSingleton<TestClass>(TestClass());
+    await getIt.unregister<TestClass>();
+
+    await expectLater(getIt.unregister<TestClass>(), throwsStateError);
+  });
+
+  test('unregister ignoreIfNotRegistered no-ops if missing', () async {
+    final getIt = GetIt.instance;
+    disposeCounter = 0;
+
+    await getIt.unregister<TestClass>(ignoreIfNotRegistered: true);
+
+    getIt.registerSingleton<TestClass>(
+      TestClass(),
+      dispose: (testClass) {
+        testClass.dispose();
+      },
+    );
+
+    await getIt.unregister<TestClass>();
+    expect(disposeCounter, 1);
+    expect(getIt.isRegistered<TestClass>(), isFalse);
+
+    await getIt.unregister<TestClass>(ignoreIfNotRegistered: true);
+    expect(disposeCounter, 1);
+    expect(getIt.isRegistered<TestClass>(), isFalse);
+  });
+
+  test('unregister ignoreIfNotRegistered by instance no-ops if missing',
+      () async {
+    final getIt = GetIt.instance;
+    final instance = TestClass();
+
+    await getIt.unregister(
+      instance: instance,
+      ignoreIfNotRegistered: true,
+    );
+
+    getIt.registerSingleton<TestClass>(instance);
+    await getIt.unregister(instance: instance);
+
+    await getIt.unregister(
+      instance: instance,
+      ignoreIfNotRegistered: true,
+    );
+    expect(getIt.isRegistered<TestClass>(), isFalse);
+  });
+
   test('change registration name with type and name', () async {
     final getIt = GetIt.instance;
     disposeCounter = 0;