fix: address review findings on RequestReviewer

- Accept 204 No Content as success (idempotent operations)
- Truncate error response body to 256 bytes (prevent log leakage)
- Add unit tests for GetAuthenticatedUser and RequestReviewer

gitea/client_test.go

@@ -5,8 +5,10 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"io"
 	"net/http"
 	"net/http/httptest"
+	"strings"
 	"testing"
 )
 
@@ -602,3 +604,83 @@ func TestIsNotFound(t *testing.T) {
 		})
 	}
 }
+
+func TestGetAuthenticatedUser(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path != "/api/v1/user" {
+			t.Errorf("unexpected path: %s", r.URL.Path)
+			http.NotFound(w, r)
+			return
+		}
+		if r.Header.Get("Authorization") != "token test-token" {
+			t.Error("missing or wrong auth header")
+		}
+		w.Header().Set("Content-Type", "application/json")
+		fmt.Fprint(w, `{"login":"my-bot","id":42}`)
+	}))
+	defer server.Close()
+
+	client := NewClient(server.URL, "test-token")
+	login, err := client.GetAuthenticatedUser(context.Background())
+	if err != nil {
+		t.Fatalf("GetAuthenticatedUser() error = %v", err)
+	}
+	if login != "my-bot" {
+		t.Errorf("login = %q, want %q", login, "my-bot")
+	}
+}
+
+func TestRequestReviewer(t *testing.T) {
+	var gotBody []byte
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != http.MethodPost {
+			t.Errorf("expected POST, got %s", r.Method)
+		}
+		expected := "/api/v1/repos/owner/repo/pulls/7/requested_reviewers"
+		if r.URL.Path != expected {
+			t.Errorf("path = %q, want %q", r.URL.Path, expected)
+		}
+		gotBody, _ = io.ReadAll(r.Body)
+		w.WriteHeader(http.StatusCreated)
+	}))
+	defer server.Close()
+
+	client := NewClient(server.URL, "test-token")
+	err := client.RequestReviewer(context.Background(), "owner", "repo", 7, "bot-user")
+	if err != nil {
+		t.Fatalf("RequestReviewer() error = %v", err)
+	}
+	if !strings.Contains(string(gotBody), `"bot-user"`) {
+		t.Errorf("body = %s, want to contain bot-user", gotBody)
+	}
+}
+
+func TestRequestReviewer_204(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusNoContent)
+	}))
+	defer server.Close()
+
+	client := NewClient(server.URL, "test-token")
+	err := client.RequestReviewer(context.Background(), "owner", "repo", 1, "user")
+	if err != nil {
+		t.Fatalf("RequestReviewer() should accept 204, got error = %v", err)
+	}
+}
+
+func TestRequestReviewer_Error(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusForbidden)
+		fmt.Fprint(w, "no permission")
+	}))
+	defer server.Close()
+
+	client := NewClient(server.URL, "test-token")
+	err := client.RequestReviewer(context.Background(), "owner", "repo", 1, "user")
+	if err == nil {
+		t.Fatal("expected error for 403 response")
+	}
+	if !strings.Contains(err.Error(), "403") {
+		t.Errorf("error should mention status code: %v", err)
+	}
+}