feat(auth): add mini program test code endpoint (#51)

internal/common/auth/service/auth_service.go

@@ -265,3 +265,32 @@ func normalizeAvatarURL(raw string) string {
 	}
 	return text
 }
+
+func (s *AuthService) GetMiniProgramTestCode(ctx context.Context, userID uint, path string, width int) ([]byte, error) {
+	var user model.User
+	if err := s.db.WithContext(ctx).Select("id, mini_program_id").First(&user, userID).Error; err != nil {
+		return nil, fmt.Errorf("find user: %w", err)
+	}
+	if user.MiniProgramID == 0 {
+		return nil, fmt.Errorf("user mini program id missing")
+	}
+
+	miniProgram, err := s.miniProgramSvc.GetByID(ctx, user.MiniProgramID)
+	if err != nil {
+		return nil, fmt.Errorf("load mini program: %w", err)
+	}
+
+	if strings.TrimSpace(path) == "" {
+		path = "pages/nsti/test?resume=0"
+	}
+	if width <= 0 {
+		width = 280
+	}
+
+	client := s.getWeChatClient(miniProgram)
+	codeBytes, err := client.GetWXACode(ctx, path, width)
+	if err != nil {
+		return nil, fmt.Errorf("get mini program test code: %w", err)
+	}
+	return codeBytes, nil
+}