From 95cb074ed9b88d20a235a8a7b051d57ea707a202 Mon Sep 17 00:00:00 2001
From: Nicholas Paun <npaun@cloudflare.com>
Date: Thu, 29 Oct 2026 07:42:40 +0000
Subject: [PATCH] Add WPT html/webappapis/timers tests

Run the .any.js tests from html/webappapis/timers, which cover
setTimeout and setInterval: clearing timers from callbacks, using
clearTimeout and clearInterval interchangeably, missing, undefined
and negative delays, and ordering of zero-delay timers.

All 10 subtests in the 7 enabled files pass, including the two
setup({single_test: true}) files that check negative delays.

- evil-spec-example.any.js is omitted: it relies on string handlers,
  which workerd does not support because it disallows eval.
- type-long-settimeout.any.js and type-long-setinterval.any.js are
  disabled because they hang. workerd clamps the delay as a double
  rather than converting it to a WebIDL long, so 2 ** 32 ms does not
  wrap to 0 and done() is never called.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---
 src/wpt/BUILD.bazel                    |  6 ++++++
 src/wpt/html/webappapis/timers-test.ts | 30 ++++++++++++++++++++++++++
 2 files changed, 36 insertions(+)
 create mode 100644 src/wpt/html/webappapis/timers-test.ts

diff --git a/src/wpt/BUILD.bazel b/src/wpt/BUILD.bazel
index ee1f9aac7aa..6f997ca8688 100644
--- a/src/wpt/BUILD.bazel
+++ b/src/wpt/BUILD.bazel
@@ -271,3 +271,9 @@ wpt_test(
     extra_wpt_directories = ["@wpt//:fetch/data-urls@module"],
     wpt_directory = "@wpt//:html/webappapis/atob@module",
 )
+
+wpt_test(
+    name = "html/webappapis/timers",
+    config = "html/webappapis/timers-test.ts",
+    wpt_directory = "@wpt//:html/webappapis/timers@module",
+)
diff --git a/src/wpt/html/webappapis/timers-test.ts b/src/wpt/html/webappapis/timers-test.ts
new file mode 100644
index 00000000000..9e708cd4eb3
--- /dev/null
+++ b/src/wpt/html/webappapis/timers-test.ts
@@ -0,0 +1,30 @@
+// Copyright (c) 2017-2026 Cloudflare, Inc.
+// Licensed under the Apache 2.0 license found in the LICENSE file or at:
+//     https://opensource.org/licenses/Apache-2.0
+
+import { type TestRunnerConfig } from 'harness/harness';
+
+export default {
+  'clearinterval-from-callback.any.js': {},
+  'cleartimeout-clearinterval.any.js': {},
+  'evil-spec-example.any.js': {
+    comment:
+      'Passes a non-function handler, which WebIDL stringifies and evaluates as code. workerd does not support string handlers because it disallows eval; setTimeout throws a TypeError at the top level.',
+    omittedTests: true,
+  },
+  'missing-timeout-setinterval.any.js': {},
+  'negative-setinterval.any.js': {},
+  'negative-settimeout.any.js': {},
+  'setinterval-settimeout-clamping.any.js': {},
+  'type-long-setinterval.any.js': {
+    comment:
+      'Hangs: workerd takes the setInterval delay as a double instead of converting it to a WebIDL long, so a delay of 2 ** 32 waits about 49 days instead of wrapping to 0. done() is never called, so the single test never completes.',
+    disabledTests: true,
+  },
+  'type-long-settimeout.any.js': {
+    comment:
+      'Hangs: workerd takes the setTimeout delay as a double instead of converting it to a WebIDL long, so a delay of 2 ** 32 waits about 49 days instead of wrapping to 0. done() is never called, so the single test never completes.',
+    disabledTests: true,
+  },
+  'zero-settimeout.any.js': {},
+} satisfies TestRunnerConfig;