fix(openai_compat): handle html error bodies and reduce allocations

2026-06-12 18:08:54 +00:00 · 2026-03-05 19:42:58 +08:00
parent a305c0a479
commit 9216cd14b5
2 changed files with 85 additions and 19 deletions
@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"log"
@@ -189,7 +190,7 @@ func (p *Provider) Chat(
 	}

 	if resp.StatusCode != http.StatusOK {
-		return nil, fmt.Errorf("API request failed:\n  Status: %d\n  Body:   %s", resp.StatusCode, string(body))
+		return nil, wrapHTTPResponseError(resp.StatusCode, body, resp.Header.Get("Content-Type"), p.apiBase)
 	}

 	out, err := parseResponse(body)
@@ -201,44 +202,77 @@ func (p *Provider) Chat(
 }

 func wrapResponseParseError(err error, body []byte, contentType, apiBase string) error {
-	trimmedContentType := strings.TrimSpace(contentType)
-	if looksLikeHTML(body, trimmedContentType) {
-		contentTypeHint := ""
-		if trimmedContentType != "" {
-			contentTypeHint = fmt.Sprintf(" (content-type: %s)", trimmedContentType)
-		}
-		return fmt.Errorf(
-			"expected JSON response from %s/chat/completions, but received HTML%s; check api_base or proxy configuration. Response preview: %s",
-			apiBase,
-			contentTypeHint,
-			responsePreview(body, 160),
-		)
+	if message, ok := htmlResponseMessage(body, contentType, apiBase); ok {
+		return errors.New(message)
 	}
 	return err
 }

+func wrapHTTPResponseError(statusCode int, body []byte, contentType, apiBase string) error {
+	if message, ok := htmlResponseMessage(body, contentType, apiBase); ok {
+		return fmt.Errorf("API request failed:\n  Status: %d\n  Detail: %s", statusCode, message)
+	}
+	return fmt.Errorf("API request failed:\n  Status: %d\n  Body:   %s", statusCode, string(body))
+}
+
+func htmlResponseMessage(body []byte, contentType, apiBase string) (string, bool) {
+	trimmedContentType := strings.TrimSpace(contentType)
+	if !looksLikeHTML(body, trimmedContentType) {
+		return "", false
+	}
+
+	contentTypeHint := ""
+	if trimmedContentType != "" {
+		contentTypeHint = fmt.Sprintf(" (content-type: %s)", trimmedContentType)
+	}
+
+	return fmt.Sprintf(
+		"expected JSON response from %s/chat/completions, but received HTML%s; check api_base or proxy configuration. Response preview: %s",
+		apiBase,
+		contentTypeHint,
+		responsePreview(body, 160),
+	), true
+}
+
 func looksLikeHTML(body []byte, contentType string) bool {
 	contentType = strings.ToLower(strings.TrimSpace(contentType))
 	if strings.Contains(contentType, "text/html") || strings.Contains(contentType, "application/xhtml+xml") {
 		return true
 	}

-	trimmed := strings.ToLower(strings.TrimSpace(string(body)))
+	trimmed := strings.ToLower(string(leadingTrimmedPrefix(body, 128)))
 	return strings.HasPrefix(trimmed, "<!doctype html") ||
 		strings.HasPrefix(trimmed, "<html") ||
 		strings.HasPrefix(trimmed, "<head") ||
 		strings.HasPrefix(trimmed, "<body")
 }

+func leadingTrimmedPrefix(body []byte, maxLen int) []byte {
+	i := 0
+	for i < len(body) {
+		switch body[i] {
+		case ' ', '\t', '\n', '\r', '\f', '\v':
+			i++
+		default:
+			end := i + maxLen
+			if end > len(body) {
+				end = len(body)
+			}
+			return body[i:end]
+		}
+	}
+	return nil
+}
+
 func responsePreview(body []byte, maxLen int) string {
-	preview := strings.TrimSpace(string(body))
-	if preview == "" {
+	trimmed := bytes.TrimSpace(body)
+	if len(trimmed) == 0 {
 		return "<empty>"
 	}
-	if len(preview) <= maxLen {
-		return preview
+	if len(trimmed) <= maxLen {
+		return string(trimmed)
 	}
-	return preview[:maxLen] + "..."
+	return string(trimmed[:maxLen]) + "..."
 }

 func parseResponse(body []byte) (*LLMResponse, error) {
@@ -1,6 +1,7 @@
 package openai_compat

 import (
+	"bytes"
 	"encoding/json"
 	"net/http"
 	"net/http/httptest"
@@ -233,6 +234,37 @@ func TestProviderChat_HTMLSuccessResponseReturnsHelpfulError(t *testing.T) {
 	}
 }

+func TestProviderChat_HTMLErrorResponseReturnsHelpfulError(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "text/html; charset=utf-8")
+		w.WriteHeader(http.StatusBadGateway)
+		_, _ = w.Write([]byte("<!DOCTYPE html><html><body>bad gateway</body></html>"))
+	}))
+	defer server.Close()
+
+	p := NewProvider("key", server.URL, "")
+	_, err := p.Chat(t.Context(), []Message{{Role: "user", Content: "hi"}}, nil, "gpt-4o", nil)
+	if err == nil {
+		t.Fatal("expected error, got nil")
+	}
+	if !strings.Contains(err.Error(), "Status: 502") {
+		t.Fatalf("expected status code in error, got %v", err)
+	}
+	if !strings.Contains(err.Error(), "received HTML") {
+		t.Fatalf("expected helpful HTML error, got %v", err)
+	}
+	if !strings.Contains(err.Error(), "check api_base or proxy configuration") {
+		t.Fatalf("expected configuration hint, got %v", err)
+	}
+}
+
+func TestLooksLikeHTML_SniffsPrefixWithLargeBody(t *testing.T) {
+	body := append([]byte(" \r\n\t<!DOCTYPE html><html><body>x</body></html>"), bytes.Repeat([]byte("A"), 1024*1024)...)
+	if !looksLikeHTML(body, "") {
+		t.Fatal("expected looksLikeHTML to detect html prefix")
+	}
+}
+
 func TestProviderChat_StripsMoonshotPrefixAndNormalizesKimiTemperature(t *testing.T) {
 	var requestBody map[string]any