Sub2API v1.0 - AI API 网关（二开初始版本，基于上游 Wei-Shaw/sub2api）

backend/internal/handler/concurrency_error_response_test.go

@@ -0,0 +1,63 @@
+package handler
+
+import (
+	"context"
+	"errors"
+	"net/http"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestConcurrencyErrorResponse(t *testing.T) {
+	tests := []struct {
+		name        string
+		err         error
+		slotType    string
+		wantStatus  int
+		wantType    string
+		wantMessage string
+	}{
+		{
+			name:        "true concurrency timeout remains rate limit",
+			err:         &ConcurrencyError{SlotType: "account", IsTimeout: true},
+			slotType:    "user",
+			wantStatus:  http.StatusTooManyRequests,
+			wantType:    "rate_limit_error",
+			wantMessage: "Concurrency limit exceeded for account, please retry later",
+		},
+		{
+			name:        "client cancellation is not classified as concurrency limit",
+			err:         context.Canceled,
+			slotType:    "user",
+			wantStatus:  statusClientClosedRequest,
+			wantType:    "api_error",
+			wantMessage: "context canceled",
+		},
+		{
+			name:        "deadline exceeded is service unavailable",
+			err:         context.DeadlineExceeded,
+			slotType:    "user",
+			wantStatus:  http.StatusServiceUnavailable,
+			wantType:    "api_error",
+			wantMessage: "Service temporarily unavailable, please retry later",
+		},
+		{
+			name:        "redis acquire error is service unavailable",
+			err:         errors.New("redis unavailable"),
+			slotType:    "user",
+			wantStatus:  http.StatusServiceUnavailable,
+			wantType:    "api_error",
+			wantMessage: "Service temporarily unavailable, please retry later",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			status, errType, message := concurrencyErrorResponse(tt.err, tt.slotType)
+			require.Equal(t, tt.wantStatus, status)
+			require.Equal(t, tt.wantType, errType)
+			require.Equal(t, tt.wantMessage, message)
+		})
+	}
+}