added tests for db and user

Backend/models/db_test.go

@@ -0,0 +1,38 @@
+package models_test
+
+import (
+	"arbeitszeitmessung/models"
+	"database/sql"
+	"testing"
+
+	_ "github.com/lib/pq"
+)
+
+type DBFixture struct {
+	Database models.IDatabase
+	TX       *sql.Tx
+}
+
+func SetupDBFixture(t *testing.T) *DBFixture {
+	t.Helper()
+
+	db, err := sql.Open("postgres", "postgres://postgres:password@localhost:5433/arbeitszeitmessung?sslmode=disable")
+	if err != nil {
+		t.Fatalf("failed to connect to database: %v", err)
+	}
+
+	tx, err := db.Begin()
+	if err != nil {
+		t.Fatalf("Failed to start transaction: %v", err)
+	}
+
+	t.Cleanup(func() {
+		tx.Rollback()
+		db.Close()
+	})
+
+	return &DBFixture{
+		Database: tx,
+		TX:       tx,
+	}
+}