events: improve argument handling, start passive

Co-authored-by: Benjamin Gruenbaum <benjamingr@gmail.com>

PR-URL: https://github.com/nodejs/node/pull/34015
Reviewed-By: Denys Otrishko <shishugi@gmail.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>

1 files changed, 32 insertions, 6 deletions

diff --git a/lib/internal/event_target.js b/lib/internal/event_target.js
index 66669b31c96..35d9e7275af 100644
--- a/lib/internal/event_target.js
+++ b/lib/internal/event_target.js
@@ -203,15 +203,31 @@ class EventTarget {
   [kRemoveListener](size, type, listener, capture) {}
 
   addEventListener(type, listener, options = {}) {
-    validateListener(listener);
-    type = String(type);
+    if (arguments.length < 2)
+      throw new ERR_MISSING_ARGS('type', 'listener');
 
+    // We validateOptions before the shouldAddListeners check because the spec
+    // requires us to hit getters.
     const {
       once,
       capture,
       passive
     } = validateEventListenerOptions(options);
 
+    if (!shouldAddListener(listener)) {
+      // The DOM silently allows passing undefined as a second argument
+      // No error code for this since it is a Warning
+      // eslint-disable-next-line no-restricted-syntax
+      const w = new Error(`addEventListener called with ${listener}` +
+                          ' which has no effect.');
+      w.name = 'AddEventListenerArgumentTypeWarning';
+      w.target = this;
+      w.type = type;
+      process.emitWarning(w);
+      return;
+    }
+    type = String(type);
+
     let root = this[kEvents].get(type);
 
     if (root === undefined) {
@@ -242,9 +258,15 @@ class EventTarget {
   }
 
   removeEventListener(type, listener, options = {}) {
-    validateListener(listener);
+    if (!shouldAddListener(listener))
+      return;
+
     type = String(type);
-    const { capture } = validateEventListenerOptions(options);
+    // TODO(@jasnell): If it's determined this cannot be backported
+    // to 12.x, then this can be simplified to:
+    //   const capture = Boolean(options?.capture);
+    const capture = options != null && options.capture === true;
+
     const root = this[kEvents].get(type);
     if (root === undefined || root.next === undefined)
       return;
@@ -426,13 +448,17 @@ Object.defineProperties(NodeEventTarget.prototype, {
 
 // EventTarget API
 
-function validateListener(listener) {
+function shouldAddListener(listener) {
   if (typeof listener === 'function' ||
       (listener != null &&
        typeof listener === 'object' &&
        typeof listener.handleEvent === 'function')) {
-    return;
+    return true;
   }
+
+  if (listener == null)
+    return false;
+
   throw new ERR_INVALID_ARG_TYPE('listener', 'EventListener', listener);
 }