ci(backend): 添加 errcheck 配置

backend/.golangci.yml

@@ -21,6 +21,34 @@ linters:
           deny:
             - pkg: sub2api/internal/repository
               desc: "service must not import repository"
+    errcheck:
+      # Report about not checking of errors in type assertions: `a := b.(MyStruct)`.
+      # Such cases aren't reported by default.
+      # Default: false
+      check-type-assertions: true
+      # report about assignment of errors to blank identifier: `num, _ := strconv.Atoi(numStr)`.
+      # Such cases aren't reported by default.
+      # Default: false
+      check-blank: false
+      # To disable the errcheck built-in exclude list.
+      # See `-excludeonly` option in https://github.com/kisielk/errcheck#excluding-functions for details.
+      # Default: false
+      disable-default-exclusions: true
+      # List of functions to exclude from checking, where each entry is a single function to exclude.
+      # See https://github.com/kisielk/errcheck#excluding-functions for details.
+      exclude-functions:
+        - io/ioutil.ReadFile
+        - io.Copy(*bytes.Buffer)
+        - io.Copy(os.Stdout)
+        - fmt.Println
+        - fmt.Print
+        - fmt.Printf
+        - fmt.Fprint
+        - fmt.Fprintf
+        - fmt.Fprintln
+      # Display function signature instead of selector.
+      # Default: false
+      verbose: true
 
 formatters:
   enable:

backend/internal/repository/claude_usage_service.go

@@ -19,7 +19,11 @@ func NewClaudeUsageFetcher() service.ClaudeUsageFetcher {
 }
 
 func (s *claudeUsageService) FetchUsage(ctx context.Context, accessToken, proxyURL string) (*service.ClaudeUsageResponse, error) {
-	transport := http.DefaultTransport.(*http.Transport).Clone()
+	transport, ok := http.DefaultTransport.(*http.Transport)
+	if !ok {
+		return nil, fmt.Errorf("failed to get default transport")
+	}
+	transport = transport.Clone()
 	if proxyURL != "" {
 		if parsedURL, err := url.Parse(proxyURL); err == nil {
 			transport.Proxy = http.ProxyURL(parsedURL)

backend/internal/service/account_usage_service.go

@@ -98,8 +98,10 @@ func (s *AccountUsageService) GetUsage(ctx context.Context, accountID int64) (*U
 	if account.CanGetUsage() {
 		// 检查缓存
 		if cached, ok := usageCacheMap.Load(accountID); ok {
-			cache := cached.(*usageCache)
-			if time.Since(cache.timestamp) < cacheTTL {
+			cache, ok := cached.(*usageCache)
+			if !ok {
+				usageCacheMap.Delete(accountID)
+			} else if time.Since(cache.timestamp) < cacheTTL {
 				return cache.data, nil
 			}
 		}