Refactor the logic and add unit test

[wickdynex]

Title:

Feature/refactor validation logic and add unit test

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Description:

This PR add a unit test to check the situation that: testProcessCreationFormWithBlankName(), testProcessCreationFormWithDuplicateName(), testProcessCreationFormWithInvalidBirthDate, testProcessUpdateFormWithBlankName(). Also classify them into each nested class. And add @NotBlank validation to pet's name in case to avoid invalid situation. Refactor the PetController.java logic, remove useless part.

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Problem:

Before this change, it does the useless object ModuleAttribute after comment @ModuleAttribute. And a field in pet name can be null. And the PetControllerTests.java didn't do the total tests to test each if branch.

• Unused Code
• Nullability Issues
• Incomplete Test Coverage

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Solution:

• Refactor the PetController logic, remove useless code from inner method and method params.
• Add @NotBlank annotation onto name field.
• Write unit test to each if branch, and test it correctness.

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Type of Change

Please select the type of change you are making:

• Bug fix (non-breaking change that fixes an issue)
• Test (unit tests added)
• Refactor (code restructuring)
• Add validate annotation

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Changes:

• Add @NotBlank annotation to name field.
• Refactor the PetController, delete attribute related code.
• Add new unit test to each if branch.

Local Test ScreenShot:

Additional Information:

I've squash all the commits into a single one. And in my opinion, some unit tests are necessary and essential, so I nested them and write new tests. Also, the name field is the important identity, it can't be null, so add @NotBlank to avoid.
If I made some mistakes or errors, plz tell me. Looking forward to your reply🥰.