Add unit tests for middleware, models, services, handlers, and repository helpers

internal/service/interest_test.go

@@ -0,0 +1,66 @@
+package service
+
+import (
+	"database/sql"
+	"testing"
+	"time"
+
+	"github.com/daniil/homelab-api/internal/model"
+)
+
+func TestCalculateInterestForDeposit_NotDeposit(t *testing.T) {
+	s := &InterestService{}
+	deposit := &model.SavingsCategory{IsDeposit: false}
+	result, err := s.CalculateInterestForDeposit(deposit)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if result != "" {
+		t.Errorf("expected empty result for non-deposit, got %q", result)
+	}
+}
+
+func TestCalculateInterestForDeposit_ZeroRate(t *testing.T) {
+	s := &InterestService{}
+	deposit := &model.SavingsCategory{IsDeposit: true, InterestRate: 0}
+	result, err := s.CalculateInterestForDeposit(deposit)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if result != "" {
+		t.Errorf("expected empty result for zero rate, got %q", result)
+	}
+}
+
+func TestCalculateInterestForDeposit_NoStartDate(t *testing.T) {
+	s := &InterestService{}
+	deposit := &model.SavingsCategory{
+		IsDeposit:    true,
+		InterestRate: 10,
+		DepositStartDate: sql.NullTime{Valid: false},
+	}
+	_, err := s.CalculateInterestForDeposit(deposit)
+	if err == nil {
+		t.Error("expected error for missing start date")
+	}
+}
+
+func TestCalculateInterestForDeposit_ExpiredDeposit(t *testing.T) {
+	s := &InterestService{}
+	deposit := &model.SavingsCategory{
+		IsDeposit:    true,
+		InterestRate: 10,
+		DepositTerm:  3, // 3 months
+		DepositStartDate: sql.NullTime{
+			Time:  time.Now().AddDate(0, -6, 0), // 6 months ago
+			Valid: true,
+		},
+	}
+	result, err := s.CalculateInterestForDeposit(deposit)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if result != "" {
+		t.Errorf("expected empty result for expired deposit, got %q", result)
+	}
+}