From f26aac103baeb2853869814d69f1977323c3acd3 Mon Sep 17 00:00:00 2001
From: XingfenD <xingfen.fendy@outlook.com>
Date: Mon, 14 Sep 2026 19:37:26 +0800
Subject: [PATCH] fix(config): validate DATABASE_URL required and parseable,
 log redis disabled (B15)

---
 backend/internal/config/config.go      | 15 +++++++++++++++
 backend/internal/config/config_test.go | 16 ++++++++++++++++
 2 files changed, 31 insertions(+)

diff --git a/backend/internal/config/config.go b/backend/internal/config/config.go
index 8e06393..394ac8c 100644
--- a/backend/internal/config/config.go
+++ b/backend/internal/config/config.go
@@ -2,11 +2,14 @@ package config
 
 import (
 	"fmt"
+	"log"
 	"os"
 	"path/filepath"
 	"strconv"
 	"strings"
 	"time"
+
+	"github.com/jackc/pgx/v5/pgxpool"
 )
 
 type Config struct {
@@ -52,6 +55,18 @@ func Load() (*Config, error) {
 	if secret == "" {
 		return nil, fmt.Errorf("JWT_SECRET required")
 	}
+	// Validate required fields.
+	dbURL := env("DATABASE_URL", "")
+	if dbURL == "" {
+		return nil, fmt.Errorf("DATABASE_URL is required")
+	}
+	if _, perr := pgxpool.ParseConfig(dbURL); perr != nil {
+		return nil, fmt.Errorf("DATABASE_URL: %w", perr)
+	}
+	if env("REDIS_URL", "") == "" {
+		log.Printf("redis disabled: rate-limit/scan-lock/page-cache off")
+	}
+
 	// resolveDir: macOS 开发机上 /var、/tmp 是指向 /private 的软链,
 	// 启动时解析一次才能让 root_path 前缀校验对上真实路径;目录不存在/出错则保留原值(Docker 路径不受影响)
 	resolveDir := func(dir string) string {
diff --git a/backend/internal/config/config_test.go b/backend/internal/config/config_test.go
index c6fd5c0..1db8cf9 100644
--- a/backend/internal/config/config_test.go
+++ b/backend/internal/config/config_test.go
@@ -6,6 +6,22 @@ import (
 	"time"
 )
 
+func TestLoadDatabaseURLRequired(t *testing.T) {
+	t.Setenv("JWT_SECRET", "x")
+	t.Setenv("DATABASE_URL", "")
+	if _, err := Load(); err == nil {
+		t.Fatal("empty DATABASE_URL must fail")
+	}
+}
+
+func TestLoadDatabaseURLMalformed(t *testing.T) {
+	t.Setenv("JWT_SECRET", "x")
+	t.Setenv("DATABASE_URL", "not a url")
+	if _, err := Load(); err == nil {
+		t.Fatal("malformed DATABASE_URL must fail")
+	}
+}
+
 func TestLoad(t *testing.T) {
 	// 屏蔽外部 env,保证默认值断言自洽(Load 将空串视为未设置)
 	t.Setenv("BOOKS_DIR", "")