Preserve maintenance timeout behavior and prepare SILO 20261026

Signed-off-by: Feng Ruohang <rh@vonng.com>

internal/ioutil/deadline_test.go

@@ -0,0 +1,62 @@
+// Copyright (c) 2026 Feng Ruohang
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+package ioutil
+
+import (
+	"context"
+	"errors"
+	"strings"
+	"testing"
+	"testing/synctest"
+	"time"
+)
+
+func TestWithDeadlineReturnsBeforeWorker(t *testing.T) {
+	for _, cancelEarly := range []bool{false, true} {
+		synctest.Test(t, func(t *testing.T) {
+			ctx, cancel := context.WithCancel(t.Context())
+			defer cancel()
+			entered, release := make(chan struct{}), make(chan struct{})
+			defer close(release)
+			done := make(chan error, 1)
+			go func() {
+				value, err := WithDeadline(ctx, time.Second, func(context.Context) (int, error) {
+					close(entered)
+					<-release
+					return 42, nil
+				})
+				if value != 0 {
+					t.Errorf("timeout returned a late worker value: %d", value)
+				}
+				done <- err
+			}()
+			<-entered
+			want := context.DeadlineExceeded
+			if cancelEarly {
+				cancel()
+				want = context.Canceled
+			} else {
+				time.Sleep(2 * time.Second)
+			}
+			synctest.Wait()
+			select {
+			case err := <-done:
+				if !errors.Is(err, want) {
+					t.Fatalf("expected %v, got %v", want, err)
+				}
+			default:
+				t.Fatal("caller still waits for the blocked worker")
+			}
+		})
+	}
+}
+
+func TestWithDeadlineContainsPanic(t *testing.T) {
+	value, err := WithDeadline(t.Context(), time.Second, func(context.Context) (int, error) {
+		panic("deadline-test")
+	})
+	if value != 0 || err == nil || !strings.Contains(err.Error(), "deadline-test") {
+		t.Fatalf("panic was not converted to an error: %d, %v", value, err)
+	}
+}