Introduce unit testing on calculation objects

Tests/Builders/StudentBuilder.cs

@@ -0,0 +1,166 @@
+using Core.Entities;
+
+namespace Tests.Builders;
+
+/// <summary>
+/// Fluent builder for creating Student test entities.
+/// </summary>
+public class StudentBuilder
+{
+    private static int _idCounter = 1;
+
+    private int _id = _idCounter++;
+    private string _firstName = "Test";
+    private string _lastName = "Student";
+    private int _grade = 9;
+    private string? _email = null;
+    private string? _phoneNumber = null;
+    private int _tsaYear = 1;
+    private string? _stateId = null;
+    private string? _regionalId = null;
+    private string? _nationalId = null;
+    private OfficerRole? _officerRole = null;
+    private List<(EventDefinition eventDef, int rank)> _rankings = new();
+
+    public StudentBuilder WithName(string firstName, string lastName)
+    {
+        _firstName = firstName;
+        _lastName = lastName;
+        return this;
+    }
+
+    public StudentBuilder WithFirstName(string firstName)
+    {
+        _firstName = firstName;
+        return this;
+    }
+
+    public StudentBuilder WithLastName(string lastName)
+    {
+        _lastName = lastName;
+        return this;
+    }
+
+    public StudentBuilder WithGrade(int grade)
+    {
+        _grade = grade;
+        return this;
+    }
+
+    public StudentBuilder WithEmail(string email)
+    {
+        _email = email;
+        return this;
+    }
+
+    public StudentBuilder WithPhone(string phoneNumber)
+    {
+        _phoneNumber = phoneNumber;
+        return this;
+    }
+
+    public StudentBuilder WithTsaYear(int year)
+    {
+        _tsaYear = year;
+        return this;
+    }
+
+    public StudentBuilder WithStateId(string stateId)
+    {
+        _stateId = stateId;
+        return this;
+    }
+
+    public StudentBuilder WithRegionalId(string regionalId)
+    {
+        _regionalId = regionalId;
+        return this;
+    }
+
+    public StudentBuilder WithNationalId(string nationalId)
+    {
+        _nationalId = nationalId;
+        return this;
+    }
+
+    public StudentBuilder AsOfficer(OfficerRole role)
+    {
+        _officerRole = role;
+        return this;
+    }
+
+    public StudentBuilder AsPresident()
+    {
+        _officerRole = OfficerRole.President;
+        return this;
+    }
+
+    public StudentBuilder AsVicePresident()
+    {
+        _officerRole = OfficerRole.VicePresident;
+        return this;
+    }
+
+    public StudentBuilder AsSecretary()
+    {
+        _officerRole = OfficerRole.Secretary;
+        return this;
+    }
+
+    public StudentBuilder AsTreasurer()
+    {
+        _officerRole = OfficerRole.Treasurer;
+        return this;
+    }
+
+    public StudentBuilder WithRanking(EventDefinition eventDef, int rank)
+    {
+        _rankings.Add((eventDef, rank));
+        return this;
+    }
+
+    public Student Build()
+    {
+        var student = new Student
+        {
+            Id = _id,
+            FirstName = _firstName,
+            LastName = _lastName,
+            Grade = _grade,
+            Email = _email,
+            PhoneNumber = _phoneNumber,
+            TsaYear = _tsaYear,
+            StateId = _stateId,
+            RegionalId = _regionalId,
+            NationalId = _nationalId,
+            OfficerRole = _officerRole,
+            Teams = new List<Team>() // Initialize Teams collection
+        };
+
+        // Set up event rankings if any were specified
+        foreach (var (eventDef, rank) in _rankings)
+        {
+            var ranking = new StudentEventRanking
+            {
+                Student = student,
+                EventDefinition = eventDef,
+                Rank = rank
+            };
+            student.EventRankings.Add(ranking);
+        }
+
+        return student;
+    }
+
+    // Static factory methods
+    public static StudentBuilder Default() => new StudentBuilder();
+
+    public static StudentBuilder Create(string firstName, string lastName) =>
+        new StudentBuilder()
+            .WithName(firstName, lastName);
+
+    /// <summary>
+    /// Reset the ID counter for test isolation. Call this in test SetUp.
+    /// </summary>
+    public static void ResetIdCounter() => _idCounter = 1;
+}