#24: Implement CreateApplicant unit test for good inputs

AggieRent.Tests/Services/ApplicantServiceTest.cs

@@ -1,6 +1,7 @@
 using AggieRent.DataAccess;
 using AggieRent.Models;
 using AggieRent.Services;
+using Microsoft.AspNetCore.Mvc;
 using Moq;
 using Xunit;
 
@@ -89,4 +90,64 @@ public void GetApplicants_ThenOk()
             mockApplicantRepository.Verify(x => x.GetAll(), Times.Once());
         }
     }
+
+    public class ApplicantService_CreateApplicantShould
+    {
+        [Fact]
+        public void CreateApplicant_GoodInput_ThenAddApplicantAndReturnId()
+        {
+            var mockApplicantRepository = new Mock<IApplicantRepository>();
+            List<Applicant> applicants =
+            [
+                new()
+                {
+                    Id = Guid.NewGuid().ToString(),
+                    Email = "[email protected]",
+                    HashedPassword = BC.HashPassword("veryStr0ngP@ssw0rd"),
+                    FirstName = "John",
+                    LastName = "Doe",
+                },
+            ];
+            mockApplicantRepository.Setup(x => x.GetAll()).Returns(applicants.AsQueryable());
+            mockApplicantRepository
+                .Setup(x => x.Add(It.IsAny<Applicant>()))
+                .Callback(
+                    (Applicant a) =>
+                    {
+                        if (applicants.FirstOrDefault(a1 => a1.Id == a.Id) != null)
+                            throw new Exception("Duplicate ID");
+                        applicants.Add(a);
+                    }
+                );
+            var applicantService = new ApplicantService(mockApplicantRepository.Object);
+
+            var email = "[email protected]";
+            var password = "superStr0ngp@ssw0rd";
+            var firstName = "John";
+            var lastName = "Deer";
+            var gender = Gender.Female;
+            var birthday = new DateOnly(2000, 1, 1);
+            var description = "Hi I'm John Deer";
+            var id = applicantService.CreateApplicant(
+                email,
+                password,
+                firstName,
+                lastName,
+                gender,
+                birthday,
+                description
+            );
+
+            Assert.Equal(2, applicants.Count);
+            var createdApplicant = applicants.FirstOrDefault(a => a.Id == id);
+            Assert.NotNull(createdApplicant);
+            Assert.Equal(email, createdApplicant.Email);
+            Assert.True(BC.Verify(password, createdApplicant.HashedPassword));
+            Assert.Equal(firstName, createdApplicant.FirstName);
+            Assert.Equal(lastName, createdApplicant.LastName);
+            Assert.Equal(gender, createdApplicant.Gender);
+            Assert.Equivalent(new DateOnly(2000, 1, 1), createdApplicant.Birthday);
+            Assert.Equal(description, createdApplicant.Description);
+        }
+    }
 }