test: add finance handler, service, repository tests

internal/repository/finance_test.go

@@ -0,0 +1,24 @@
+package repository
+
+import (
+	"testing"
+)
+
+func TestNewFinanceRepository(t *testing.T) {
+	repo := NewFinanceRepository(nil)
+	if repo == nil {
+		t.Error("expected non-nil FinanceRepository")
+	}
+	if repo.db != nil {
+		t.Error("expected nil db")
+	}
+}
+
+func TestFinanceCategoryErrors(t *testing.T) {
+	if ErrFinanceCategoryNotFound.Error() != "finance category not found" {
+		t.Errorf("unexpected error message: %s", ErrFinanceCategoryNotFound.Error())
+	}
+	if ErrFinanceTransactionNotFound.Error() != "finance transaction not found" {
+		t.Errorf("unexpected error message: %s", ErrFinanceTransactionNotFound.Error())
+	}
+}