diff --git a/packages/wyatt_authentication_bloc/test/sign_up/sign_up_cubit_test.dart b/packages/wyatt_authentication_bloc/test/sign_up/sign_up_cubit_test.dart
index 0fe84d1a..3d54a978 100644
--- a/packages/wyatt_authentication_bloc/test/sign_up/sign_up_cubit_test.dart
+++ b/packages/wyatt_authentication_bloc/test/sign_up/sign_up_cubit_test.dart
@@ -481,5 +481,178 @@ void main() {
         ],
       );
     });
+
+    group('update', () {
+      final inputsA = <
+          FormInput<dynamic, FormInputValidator<dynamic, ValidationError>,
+              dynamic>>[
+        FormInput(AuthFormField.email, const Email.pure()),
+        FormInput(AuthFormField.password, const Password.pure())
+      ];
+
+      final inputsB = <
+          FormInput<dynamic, FormInputValidator<dynamic, ValidationError>,
+              dynamic>>[
+        FormInput('name', const Name.pure()),
+        FormInput('phone', const Phone.pure()),
+      ];
+
+      final inputsC = <
+          FormInput<dynamic, FormInputValidator<dynamic, ValidationError>,
+              dynamic>>[
+        FormInput(AuthFormField.email, const Email.pure()),
+        FormInput(AuthFormField.password, const Password.pure()),
+        FormInput('name', const Name.pure()),
+        FormInput('phone', const Phone.pure()),
+      ];
+
+      blocTest<SignUpCubit<int>, SignUpState>(
+        'emits no state when apply intersection with the same form',
+        build: () => SignUpCubit(
+          authenticationRepository: authenticationRepository,
+        ),
+        seed: () => SignUpState(
+          form: WyattFormImpl(
+            inputsA,
+            name: AuthFormName.signUpForm,
+          ),
+        ),
+        act: (cubit) => cubit.update(
+          WyattFormImpl(inputsA, name: 'otherSignUpForm'),
+          operation: SetOperation.intersection,
+        ),
+        expect: () => <SignUpState>[],
+      );
+
+      blocTest<SignUpCubit<int>, SignUpState>(
+        'emits no state when apply intersection with a form that '
+        'contains every inputs of actual form',
+        build: () => SignUpCubit(
+          authenticationRepository: authenticationRepository,
+        ),
+        seed: () => SignUpState(
+          form: WyattFormImpl(
+            inputsA,
+            name: AuthFormName.signUpForm,
+          ),
+        ),
+        act: (cubit) => cubit.update(
+          WyattFormImpl(inputsC, name: 'otherSignUpForm'),
+          operation: SetOperation.intersection,
+        ),
+        expect: () => <SignUpState>[],
+      );
+
+      blocTest<SignUpCubit<int>, SignUpState>(
+        'emits the form intersection when apply '
+        'intersection with a smaller form',
+        build: () => SignUpCubit(
+          authenticationRepository: authenticationRepository,
+        ),
+        seed: () => SignUpState(
+          form: WyattFormImpl(
+            inputsC,
+            name: AuthFormName.signUpForm,
+          ),
+        ),
+        act: (cubit) => cubit.update(
+          WyattFormImpl(inputsA, name: 'otherSignUpForm'),
+          operation: SetOperation.intersection,
+        ),
+        expect: () => <SignUpState>[
+          SignUpState(
+            form: WyattFormImpl(
+              inputsA,
+              name: AuthFormName.signUpForm,
+            ),
+          ),
+        ],
+      );
+
+      blocTest<SignUpCubit<int>, SignUpState>(
+        'emits no state when apply union with the same form',
+        build: () => SignUpCubit(
+          authenticationRepository: authenticationRepository,
+        ),
+        seed: () => SignUpState(
+          form: WyattFormImpl(
+            inputsA,
+            name: AuthFormName.signUpForm,
+          ),
+        ),
+        act: (cubit) => cubit.update(
+          WyattFormImpl(inputsA, name: 'otherSignUpForm'),
+          operation: SetOperation.union,
+        ),
+        expect: () => <SignUpState>[],
+      );
+
+      blocTest<SignUpCubit<int>, SignUpState>(
+        'emits the form union when apply '
+        'union with an another form',
+        build: () => SignUpCubit(
+          authenticationRepository: authenticationRepository,
+        ),
+        seed: () => SignUpState(
+          form: WyattFormImpl(
+            inputsA,
+            name: AuthFormName.signUpForm,
+          ),
+        ),
+        act: (cubit) => cubit.update(
+          WyattFormImpl(inputsB, name: 'otherSignUpForm'),
+          operation: SetOperation.union,
+        ),
+        expect: () => <SignUpState>[
+          SignUpState(
+            form: WyattFormImpl(
+              inputsC,
+              name: AuthFormName.signUpForm,
+            ),
+          ),
+        ],
+      );
+
+      blocTest<SignUpCubit<int>, SignUpState>(
+        'emits no state when apply replace with the same form',
+        build: () => SignUpCubit(
+          authenticationRepository: authenticationRepository,
+        ),
+        seed: () => SignUpState(
+          form: WyattFormImpl(
+            inputsA,
+            name: AuthFormName.signUpForm,
+          ),
+        ),
+        act: (cubit) => cubit.update(
+          WyattFormImpl(inputsA, name: AuthFormName.signUpForm),
+        ),
+        expect: () => <SignUpState>[],
+      );
+
+      blocTest<SignUpCubit<int>, SignUpState>(
+        'emits a state with a new form after the replacement',
+        build: () => SignUpCubit(
+          authenticationRepository: authenticationRepository,
+        ),
+        seed: () => SignUpState(
+          form: WyattFormImpl(
+            inputsA,
+            name: AuthFormName.signUpForm,
+          ),
+        ),
+        act: (cubit) => cubit.update(
+          WyattFormImpl(inputsC, name: AuthFormName.signUpForm),
+        ),
+        expect: () => <SignUpState>[
+          SignUpState(
+            form: WyattFormImpl(
+              inputsC,
+              name: AuthFormName.signUpForm,
+            ),
+          ),
+        ],
+      );
+    });
   });
 }