From 0c6cc6ec8d6e75c019adf75cb4b27c0d78e71dc5 Mon Sep 17 00:00:00 2001
From: Daeyeon Jeong <daeyeon.dev@gmail.com>
Date: Mon, 18 Jul 2022 14:24:33 +0900
Subject: [PATCH 1/3] events: expose CustomEvent on global with CLI flag

Signed-off-by: Daeyeon Jeong daeyeon.dev@gmail.com
---
 doc/api/cli.md                           | 10 ++++++++++
 doc/api/globals.md                       | 15 +++++++++++++++
 doc/node.1                               |  3 +++
 lib/.eslintrc.yaml                       |  2 ++
 lib/internal/bootstrap/pre_execution.js  | 13 +++++++++++++
 lib/internal/main/worker_thread.js       |  2 ++
 src/node_options.cc                      |  4 ++++
 src/node_options.h                       |  1 +
 test/common/index.js                     |  3 +++
 test/parallel/test-global-customevent.js | 16 ++++++++++++++++
 10 files changed, 69 insertions(+)
 create mode 100644 test/parallel/test-global-customevent.js

diff --git a/doc/api/cli.md b/doc/api/cli.md
index a2861024659af2..f0a2e70b8d7b66 100644
--- a/doc/api/cli.md
+++ b/doc/api/cli.md
@@ -280,6 +280,14 @@ effort to report stack traces relative to the original source file.
 Overriding `Error.prepareStackTrace` prevents `--enable-source-maps` from
 modifying the stack trace.
 
+### `--experimental-global-customevent`
+
+<!-- YAML
+added: REPLACEME
+-->
+
+Expose the [CustomEvent Web API][] on the global scope.
+
 ### `--experimental-global-webcrypto`
 
 <!-- YAML
@@ -1652,6 +1660,7 @@ Node.js options that are allowed are:
 * `--enable-fips`
 * `--enable-source-maps`
 * `--experimental-abortcontroller`
+* `--experimental-global-customevent`
 * `--experimental-global-webcrypto`
 * `--experimental-import-meta-resolve`
 * `--experimental-json-modules`
@@ -2077,6 +2086,7 @@ done
 [#42511]: https://github.com/nodejs/node/issues/42511
 [Chrome DevTools Protocol]: https://chromedevtools.github.io/devtools-protocol/
 [CommonJS]: modules.md
+[CustomEvent Web API]: https://dom.spec.whatwg.org/#customevent
 [ECMAScript module loader]: esm.md#loaders
 [Fetch API]: https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API
 [Modules loaders]: packages.md#modules-loaders
diff --git a/doc/api/globals.md b/doc/api/globals.md
index 84ed94a1e5eca0..a3e52520af637a 100644
--- a/doc/api/globals.md
+++ b/doc/api/globals.md
@@ -380,6 +380,19 @@ A browser-compatible implementation of {CryptoKey}. This global is available
 only if the Node.js binary was compiled with including support for the
 `node:crypto` module.
 
+## `CustomEvent`
+
+<!-- YAML
+added: REPLACEME
+-->
+
+> Stability: 1 - Experimental. Enable this API with the
+> [`--experimental-global-customevent`][] CLI flag.
+
+<!-- type=global -->
+
+A browser-compatible implementation of the [`CustomEvent` Web API][].
+
 ## Class: `DecompressionStream`
 
 <!-- YAML
@@ -852,12 +865,14 @@ added: v18.0.0
 A browser-compatible implementation of [`WritableStreamDefaultWriter`][].
 
 [Web Crypto API]: webcrypto.md
+[`--experimental-global-customevent`]: cli.md#--experimental-global-customevent
 [`--experimental-global-webcrypto`]: cli.md#--experimental-global-webcrypto
 [`--no-experimental-fetch`]: cli.md#--no-experimental-fetch
 [`AbortController`]: https://developer.mozilla.org/en-US/docs/Web/API/AbortController
 [`ByteLengthQueuingStrategy`]: webstreams.md#class-bytelengthqueuingstrategy
 [`CompressionStream`]: webstreams.md#class-compressionstream
 [`CountQueuingStrategy`]: webstreams.md#class-countqueuingstrategy
+[`CustomEvent` Web API]: https://dom.spec.whatwg.org/#customevent
 [`DOMException`]: https://developer.mozilla.org/en-US/docs/Web/API/DOMException
 [`DecompressionStream`]: webstreams.md#class-decompressionstream
 [`EventTarget` and `Event` API]: events.md#eventtarget-and-event-api
diff --git a/doc/node.1 b/doc/node.1
index 6ac0d6758342fb..141519b74b5c6a 100644
--- a/doc/node.1
+++ b/doc/node.1
@@ -139,6 +139,9 @@ Requires Node.js to be built with
 .It Fl -enable-source-maps
 Enable Source Map V3 support for stack traces.
 .
+.It Fl -experimental-global-customevent
+Expose the CustomEvent on the global scope.
+.
 .It Fl -experimental-global-webcrypto
 Expose the Web Crypto API on the global scope.
 .
diff --git a/lib/.eslintrc.yaml b/lib/.eslintrc.yaml
index fae5e85ce174b4..2cfbf0894f2a3a 100644
--- a/lib/.eslintrc.yaml
+++ b/lib/.eslintrc.yaml
@@ -49,6 +49,8 @@ rules:
       message: Use `const { CompressionStream } = require('internal/webstreams/compression')` instead of the global.
     - name: CountQueuingStrategy
       message: Use `const { CountQueuingStrategy } = require('internal/webstreams/queuingstrategies')` instead of the global.
+    - name: CustomEvent
+      message: Use `const { CustomEvent } = require('internal/event_target');` instead of the global.
     - name: DecompressionStream
       message: Use `const { DecompressionStream } = require('internal/webstreams/compression')` instead of the global.
     - name: DOMException
diff --git a/lib/internal/bootstrap/pre_execution.js b/lib/internal/bootstrap/pre_execution.js
index 80092bf74e1676..823f2515f4f704 100644
--- a/lib/internal/bootstrap/pre_execution.js
+++ b/lib/internal/bootstrap/pre_execution.js
@@ -44,6 +44,7 @@ function prepareMainThreadExecution(expandArgv1 = false,
   setupWarningHandler();
   setupFetch();
   setupWebCrypto();
+  setupCustomEvent();
 
   // Resolve the coverage directory to an absolute path, and
   // overwrite process.env so that the original path gets passed
@@ -249,6 +250,17 @@ function setupWebCrypto() {
   }
 }
 
+// TODO(daeyeon): move this to internal/bootstrap/browser when the CLI flag is
+//                removed.
+function setupCustomEvent() {
+  if (process.config.variables.node_no_browser_globals ||
+      !getOptionValue('--experimental-global-customevent')) {
+    return;
+  }
+  const { CustomEvent } = require('internal/event_target');
+  exposeInterface(globalThis, 'CustomEvent', CustomEvent);
+}
+
 // Setup User-facing NODE_V8_COVERAGE environment variable that writes
 // ScriptCoverage to a specified file.
 function setupCoverageHooks(dir) {
@@ -567,6 +579,7 @@ module.exports = {
   setupWarningHandler,
   setupFetch,
   setupWebCrypto,
+  setupCustomEvent,
   setupDebugEnv,
   setupPerfHooks,
   prepareMainThreadExecution,
diff --git a/lib/internal/main/worker_thread.js b/lib/internal/main/worker_thread.js
index 91ca93e6e10062..e21c1b1fe2cc7f 100644
--- a/lib/internal/main/worker_thread.js
+++ b/lib/internal/main/worker_thread.js
@@ -19,6 +19,7 @@ const {
   setupWarningHandler,
   setupFetch,
   setupWebCrypto,
+  setupCustomEvent,
   setupDebugEnv,
   setupPerfHooks,
   initializeDeprecations,
@@ -71,6 +72,7 @@ setupDebugEnv();
 setupWarningHandler();
 setupFetch();
 setupWebCrypto();
+setupCustomEvent();
 initializeSourceMapsHandlers();
 
 // Since worker threads cannot switch cwd, we do not need to
diff --git a/src/node_options.cc b/src/node_options.cc
index 25e4caf98ad210..7a41f9bc3b87f6 100644
--- a/src/node_options.cc
+++ b/src/node_options.cc
@@ -339,6 +339,10 @@ EnvironmentOptionsParser::EnvironmentOptionsParser() {
             &EnvironmentOptions::experimental_fetch,
             kAllowedInEnvironment,
             true);
+  AddOption("--experimental-global-customevent",
+            "expose experimental CustomEvent on the global scope",
+            &EnvironmentOptions::experimental_global_customevent,
+            kAllowedInEnvironment);
   AddOption("--experimental-global-webcrypto",
             "expose experimental Web Crypto API on the global scope",
             &EnvironmentOptions::experimental_global_web_crypto,
diff --git a/src/node_options.h b/src/node_options.h
index a4744fb9e5b8a5..827c6298f5ea28 100644
--- a/src/node_options.h
+++ b/src/node_options.h
@@ -108,6 +108,7 @@ class EnvironmentOptions : public Options {
   std::string dns_result_order;
   bool enable_source_maps = false;
   bool experimental_fetch = true;
+  bool experimental_global_customevent = false;
   bool experimental_global_web_crypto = false;
   bool experimental_https_modules = false;
   std::string experimental_specifier_resolution;
diff --git a/test/common/index.js b/test/common/index.js
index 7d6fed2f32007c..e14fbe59d1946b 100644
--- a/test/common/index.js
+++ b/test/common/index.js
@@ -315,6 +315,9 @@ if (hasCrypto && global.crypto) {
   knownGlobals.push(global.CryptoKey);
   knownGlobals.push(global.SubtleCrypto);
 }
+if (global.CustomEvent) {
+  knownGlobals.push(global.CustomEvent);
+}
 if (global.ReadableStream) {
   knownGlobals.push(
     global.ReadableStream,
diff --git a/test/parallel/test-global-customevent.js b/test/parallel/test-global-customevent.js
new file mode 100644
index 00000000000000..610ce011ae8b7b
--- /dev/null
+++ b/test/parallel/test-global-customevent.js
@@ -0,0 +1,16 @@
+// Flags: --experimental-global-customevent --expose-internals
+'use strict';
+
+const common = require('../common');
+const { strictEqual, ok } = require('node:assert');
+const { Worker, isMainThread } = require('worker_threads');
+const { CustomEvent } = require('internal/event_target');
+
+ok(CustomEvent);
+strictEqual(globalThis.CustomEvent, CustomEvent);
+
+if (isMainThread) {
+  const w = new Worker(__filename);
+  w.on('message', common.mustNotCall());
+  w.on('error', common.mustNotCall());
+}

From 323ca0f36c9b1457a00f6d3ad37a0feacc53801e Mon Sep 17 00:00:00 2001
From: Daeyeon Jeong <daeyeon.dev@gmail.com>
Date: Mon, 18 Jul 2022 18:51:21 +0900
Subject: [PATCH 2/3] fixup: clarify the test

Signed-off-by: Daeyeon Jeong daeyeon.dev@gmail.com
---
 .eslintrc.js                             |  1 +
 test/parallel/test-global-customevent.js | 13 ++++---------
 2 files changed, 5 insertions(+), 9 deletions(-)

diff --git a/.eslintrc.js b/.eslintrc.js
index 167107a0018e08..1dedcd1bd76e15 100644
--- a/.eslintrc.js
+++ b/.eslintrc.js
@@ -321,6 +321,7 @@ module.exports = {
     ByteLengthQueuingStrategy: 'readable',
     CompressionStream: 'readable',
     CountQueuingStrategy: 'readable',
+    CustomEvent: 'readable',
     Crypto: 'readable',
     CryptoKey: 'readable',
     DecompressionStream: 'readable',
diff --git a/test/parallel/test-global-customevent.js b/test/parallel/test-global-customevent.js
index 610ce011ae8b7b..a113631a997bb9 100644
--- a/test/parallel/test-global-customevent.js
+++ b/test/parallel/test-global-customevent.js
@@ -1,16 +1,11 @@
 // Flags: --experimental-global-customevent --expose-internals
 'use strict';
 
-const common = require('../common');
+require('../common');
 const { strictEqual, ok } = require('node:assert');
-const { Worker, isMainThread } = require('worker_threads');
-const { CustomEvent } = require('internal/event_target');
+const { CustomEvent: internalCustomEvent } = require('internal/event_target');
 
+// Global
 ok(CustomEvent);
-strictEqual(globalThis.CustomEvent, CustomEvent);
 
-if (isMainThread) {
-  const w = new Worker(__filename);
-  w.on('message', common.mustNotCall());
-  w.on('error', common.mustNotCall());
-}
+strictEqual(CustomEvent, internalCustomEvent);

From 6bc06556aca50f15f174118ac9ce6a4edcbeb50b Mon Sep 17 00:00:00 2001
From: Daeyeon Jeong <daeyeon.dev@gmail.com>
Date: Mon, 18 Jul 2022 21:24:26 +0900
Subject: [PATCH 3/3] fixup: update the wpt event test

Signed-off-by: Daeyeon Jeong daeyeon.dev@gmail.com
---
 test/wpt/status/dom/events.json | 6 +-----
 test/wpt/test-events.js         | 2 ++
 2 files changed, 3 insertions(+), 5 deletions(-)

diff --git a/test/wpt/status/dom/events.json b/test/wpt/status/dom/events.json
index 9266118feca49f..aa7ba73eb39f7c 100644
--- a/test/wpt/status/dom/events.json
+++ b/test/wpt/status/dom/events.json
@@ -20,17 +20,13 @@
     "fail": {
       "unexpected": [
         "assert_true: expected true got false",
-        "assert_array_equals: lengths differ, expected array [\"bubbles\", \"cancelable\"] length 2, got [\"cancelable\", \"bubbles\", \"sweet\"] length 3",
-        "CustomEvent is not defined"
+        "assert_array_equals: lengths differ, expected array [\"bubbles\", \"cancelable\"] length 2, got [\"cancelable\", \"bubbles\", \"sweet\"] length 3"
       ]
     }
   },
   "EventListener-addEventListener.sub.window.js": {
     "fail": "document is not defined"
   },
-  "EventTarget-constructible.any.js": {
-    "fail": "CustomEvent is not defined"
-  },
   "relatedTarget.window.js": {
     "fail": "document is not defined"
   },
diff --git a/test/wpt/test-events.js b/test/wpt/test-events.js
index 5040d56d6a2c58..6d4a4cff2d9fdc 100644
--- a/test/wpt/test-events.js
+++ b/test/wpt/test-events.js
@@ -4,4 +4,6 @@ const { WPTRunner } = require('../common/wpt');
 
 const runner = new WPTRunner('dom/events');
 
+runner.setFlags(['--experimental-global-customevent']);
+
 runner.runJsTests();