[cosmiinn75]

Description

• Added @NotNull to the applications field in MenteeRegistration.
• Added a regression test to ensure that missing applications return HTTP 400 instead of 500.
• Verified that the test fails without the fix and passes with it.

Related Issue

Fixes #740

Change Type

• Bug Fix
• New Feature
• Code Refactor
• Documentation
• Test
• Other

Screenshots

Not applicable.

Pull request checklist

• I checked and followed the [contributor guide](../CONTRIBUTING.md).
• I have tested my changes locally.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[goelsonali]

Can we avoid, raw json content in file, yes it has been used before in previous tests but that is incorrect, would be good to clean-up that as well.

Why - Makes it harder to read the test data.

Suggested change

	"{\"mentee\":{\"id\":2,\"fullName\":\"Mark\",\"email\":\"mark@test.com\",\"position\":\"Software Engineer\",\"slackDisplayName\":\"mark-slack\",\"country\":{\"countryCode\":\"US\",\"countryName\":\"USA\"},\"city\":\"New York\",\"companyName\":\"Tech Corp\",\"images\":[],\"network\":[],\"profileStatus\":\"ACTIVE\",\"bio\":\"Mentee bio\",\"skills\":{\"yearsExperience\":2,\"areas\":[{\"technicalArea\":\"BACKEND\",\"proficiencyLevel\":\"BEGINNER\"}],\"languages\":[{\"language\":\"JAVASCRIPT\",\"proficiencyLevel\":\"BEGINNER\"}],\"mentorshipFocus\":[\"GROW_BEGINNER_TO_MID\"]}},\"mentorshipType\":\"AD_HOC\",\"cycleYear\":\""
	@Test
	@DisplayName(
	"Given null applications in registration, when creating mentee, then return 400 Bad Request")
	void shouldReturn400WhenApplicationsIsNull() throws Exception {
	var mockMentee = createMenteeTest(2L, "Mark", "mark@test.com");
	var registration =
	new MenteeRegistration(mockMentee, MentorshipType.AD_HOC, Year.now(), null);
	mockMvc
	.perform(
	MockMvcRequestBuilders.post(API_MENTEES)
	.header(API_KEY_HEADER, API_KEY_VALUE)
	.contentType(APPLICATION_JSON)
	.content(objectMapper.writeValueAsString(registration)))
	.andExpect(status().isBadRequest());
	}