feat: Complete DI cleanup - migrate test helpers to Database struct

- Update internal/db/test_helpers.go to use Database struct instead of globals
- Update internal/server/test_helpers.go to use TestDatabase.Pool
- Add TODO comment to old Dbpool/Ctx globals in dbHelper.go
- Remove db.Testf() usage from production code (kept for deprecated /dbtest endpoint)

Generated by Mistral Vibe.
Co-Authored-By: Mistral Vibe <vibe@mistral.ai>

internal/db/dbHelper.go

@@ -20,6 +20,7 @@ import (
 	"go.uber.org/zap"
 )
 
+// TODO: Remove these global variables once test_helpers.go is fully migrated to use Database struct
 var Dbpool *pgxpool.Pool
 var Ctx = context.Background()
 

internal/db/test_helpers.go

@@ -1,6 +1,7 @@
 package db
 
 import (
+	"context"
 	"database/sql"
 	"fmt"
 	"log"
@@ -16,6 +17,8 @@ var (
 	testDBUser      string
 	testDBPassword  string
 	testDBName      string
+	// TestDatabase is the database instance for tests
+	TestDatabase *Database
 )
 
 // TestSetupDB initializes the test database using existing functions
@@ -44,9 +47,17 @@ func TestSetupDB(t *testing.T) {
 		// Create the database first (testuser is a superuser in the container)
 		createTestDatabase(host, port, dbname, user, password)
 
-		// Now run migrations using the existing function
-		Migrate_db(host, port, user, password, dbname)
-		InitDB(host, port, user, password, dbname)
+		// Create database instance and run migrations
+		var err error
+		TestDatabase, err = NewDatabase(host, port, user, password, dbname)
+		if err != nil {
+			t.Fatalf("Failed to initialize test database: %v", err)
+		}
+
+		// Run migrations
+		if err := TestDatabase.RunMigrations(); err != nil {
+			t.Fatalf("Failed to run migrations: %v", err)
+		}
 	})
 }
 
@@ -86,12 +97,16 @@ func createTestDatabase(host, port, dbname, user, password string) {
 // "closed pool" errors when tests run sequentially
 func TestTearDownDB(t *testing.T) {
 	// CloseDb() // Disabled to prevent pool closure between sequential tests
+	if TestDatabase != nil {
+		TestDatabase.Close()
+		TestDatabase = nil
+	}
 }
 
 // TestClearDatabase clears all data from the test database
 // Useful for running tests with a clean slate
 func TestClearDatabase(t *testing.T) {
-	if Dbpool == nil {
+	if TestDatabase == nil || TestDatabase.Pool == nil {
 		t.Skip("Database not initialized")
 	}
 
@@ -103,15 +118,16 @@ func TestClearDatabase(t *testing.T) {
 		"game",
 	}
 
+	ctx := context.Background()
 	for _, table := range tables {
-		_, err := Dbpool.Exec(Ctx, "TRUNCATE TABLE "+table+" CASCADE")
+		_, err := TestDatabase.Pool.Exec(ctx, "TRUNCATE TABLE "+table+" CASCADE")
 		if err != nil {
 			t.Logf("Failed to truncate table %s: %v", table, err)
 		}
 	}
 
 	// Reset sequences
-	_, err := Dbpool.Exec(Ctx, "SELECT setval('game_id_seq', 1, false)")
+	_, err := TestDatabase.Pool.Exec(ctx, "SELECT setval('game_id_seq', 1, false)")
 	if err != nil {
 		t.Logf("Failed to reset game_id_seq: %v", err)
 	}

internal/server/test_helpers.go

@@ -51,19 +51,16 @@ func StartTestServer(t *testing.T) *echo.Echo {
 	// Initialize database for tests
 	db.TestSetupDB(t)
 	
-	// Initialize backend with the global Dbpool
+	// Initialize backend with test database pool
 	// This ensures BackendRepo() and BackendCtx() are available
-	if db.Dbpool != nil {
-		backend.InitBackend(db.Dbpool)
+	if db.TestDatabase != nil && db.TestDatabase.Pool != nil {
+		backend.InitBackend(db.TestDatabase.Pool)
 	}
 
 	// Create a Server instance and get its routes
 	s := &Server{
-		db: &db.Database{
-			Pool: db.Dbpool,
-			Ctx:  db.Ctx,
-		},
-		tokenHandler: NewTokenHandler(db.Dbpool),
+		db:            db.TestDatabase,
+		tokenHandler:   NewTokenHandler(db.TestDatabase.Pool),
 	}
 	handler := s.RegisterRoutes()