1 files changed, 1111 insertions, 0 deletions
diff --git a/ext/node/polyfills/internal/event_target.mjs b/ext/node/polyfills/internal/event_target.mjs
new file mode 100644
index 000000000..d542fba94
--- /dev/null
+++ b/ext/node/polyfills/internal/event_target.mjs
@@ -0,0 +1,1111 @@
+// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
+// Copyright Node.js contributors. All rights reserved. MIT License.
+
+import {
+  ERR_EVENT_RECURSION,
+  ERR_INVALID_ARG_TYPE,
+  ERR_INVALID_THIS,
+  ERR_MISSING_ARGS,
+} from "internal:deno_node/polyfills/internal/errors.ts";
+import { validateObject, validateString } from "internal:deno_node/polyfills/internal/validators.mjs";
+import { emitWarning } from "internal:deno_node/polyfills/process.ts";
+import { nextTick } from "internal:deno_node/polyfills/_next_tick.ts";
+import { Event as WebEvent, EventTarget as WebEventTarget } from "internal:deno_web/02_event.js";
+
+import {
+  customInspectSymbol,
+  kEmptyObject,
+  kEnumerableProperty,
+} from "internal:deno_node/polyfills/internal/util.mjs";
+import { inspect } from "internal:deno_node/polyfills/util.ts";
+
+const kIsEventTarget = Symbol.for("nodejs.event_target");
+const kIsNodeEventTarget = Symbol("kIsNodeEventTarget");
+
+import { EventEmitter } from "internal:deno_node/polyfills/events.ts";
+const {
+  kMaxEventTargetListeners,
+  kMaxEventTargetListenersWarned,
+} = EventEmitter;
+
+const kEvents = Symbol("kEvents");
+const kIsBeingDispatched = Symbol("kIsBeingDispatched");
+const kStop = Symbol("kStop");
+const kTarget = Symbol("kTarget");
+const kHandlers = Symbol("khandlers");
+const kWeakHandler = Symbol("kWeak");
+
+const kHybridDispatch = Symbol.for("nodejs.internal.kHybridDispatch");
+const kCreateEvent = Symbol("kCreateEvent");
+const kNewListener = Symbol("kNewListener");
+const kRemoveListener = Symbol("kRemoveListener");
+const kIsNodeStyleListener = Symbol("kIsNodeStyleListener");
+const kTrustEvent = Symbol("kTrustEvent");
+
+const kType = Symbol("type");
+const kDetail = Symbol("detail");
+const kDefaultPrevented = Symbol("defaultPrevented");
+const kCancelable = Symbol("cancelable");
+const kTimestamp = Symbol("timestamp");
+const kBubbles = Symbol("bubbles");
+const kComposed = Symbol("composed");
+const kPropagationStopped = Symbol("propagationStopped");
+
+function isEvent(value) {
+  return typeof value?.[kType] === "string";
+}
+
+class Event extends WebEvent {
+  /**
+   * @param {string} type
+   * @param {{
+   *   bubbles?: boolean,
+   *   cancelable?: boolean,
+   *   composed?: boolean,
+   * }} [options]
+   */
+  constructor(type, options = null) {
+    super(type, options);
+    if (arguments.length === 0) {
+      throw new ERR_MISSING_ARGS("type");
+    }
+    validateObject(options, "options", {
+      allowArray: true,
+      allowFunction: true,
+      nullable: true,
+    });
+    const { cancelable, bubbles, composed } = { ...options };
+    this[kCancelable] = !!cancelable;
+    this[kBubbles] = !!bubbles;
+    this[kComposed] = !!composed;
+    this[kType] = `${type}`;
+    this[kDefaultPrevented] = false;
+    this[kTimestamp] = performance.now();
+    this[kPropagationStopped] = false;
+    this[kTarget] = null;
+    this[kIsBeingDispatched] = false;
+  }
+
+  [customInspectSymbol](depth, options) {
+    if (!isEvent(this)) {
+      throw new ERR_INVALID_THIS("Event");
+    }
+    const name = this.constructor.name;
+    if (depth < 0) {
+      return name;
+    }
+
+    const opts = Object.assign({}, options, {
+      depth: NumberIsInteger(options.depth) ? options.depth - 1 : options.depth,
+    });
+
+    return `${name} ${
+      inspect({
+        type: this[kType],
+        defaultPrevented: this[kDefaultPrevented],
+        cancelable: this[kCancelable],
+        timeStamp: this[kTimestamp],
+      }, opts)
+    }`;
+  }
+
+  stopImmediatePropagation() {
+    if (!isEvent(this)) {
+      throw new ERR_INVALID_THIS("Event");
+    }
+    this[kStop] = true;
+  }
+
+  preventDefault() {
+    if (!isEvent(this)) {
+      throw new ERR_INVALID_THIS("Event");
+    }
+    this[kDefaultPrevented] = true;
+  }
+
+  /**
+   * @type {EventTarget}
+   */
+  get target() {
+    if (!isEvent(this)) {
+      throw new ERR_INVALID_THIS("Event");
+    }
+    return this[kTarget];
+  }
+
+  /**
+   * @type {EventTarget}
+   */
+  get currentTarget() {
+    if (!isEvent(this)) {
+      throw new ERR_INVALID_THIS("Event");
+    }
+    return this[kTarget];
+  }
+
+  /**
+   * @type {EventTarget}
+   */
+  get srcElement() {
+    if (!isEvent(this)) {
+      throw new ERR_INVALID_THIS("Event");
+    }
+    return this[kTarget];
+  }
+
+  /**
+   * @type {string}
+   */
+  get type() {
+    if (!isEvent(this)) {
+      throw new ERR_INVALID_THIS("Event");
+    }
+    return this[kType];
+  }
+
+  /**
+   * @type {boolean}
+   */
+  get cancelable() {
+    if (!isEvent(this)) {
+      throw new ERR_INVALID_THIS("Event");
+    }
+    return this[kCancelable];
+  }
+
+  /**
+   * @type {boolean}
+   */
+  get defaultPrevented() {
+    if (!isEvent(this)) {
+      throw new ERR_INVALID_THIS("Event");
+    }
+    return this[kCancelable] && this[kDefaultPrevented];
+  }
+
+  /**
+   * @type {number}
+   */
+  get timeStamp() {
+    if (!isEvent(this)) {
+      throw new ERR_INVALID_THIS("Event");
+    }
+    return this[kTimestamp];
+  }
+
+  // The following are non-op and unused properties/methods from Web API Event.
+  // These are not supported in Node.js and are provided purely for
+  // API completeness.
+  /**
+   * @returns {EventTarget[]}
+   */
+  composedPath() {
+    if (!isEvent(this)) {
+      throw new ERR_INVALID_THIS("Event");
+    }
+    return this[kIsBeingDispatched] ? [this[kTarget]] : [];
+  }
+
+  /**
+   * @type {boolean}
+   */
+  get returnValue() {
+    if (!isEvent(this)) {
+      throw new ERR_INVALID_THIS("Event");
+    }
+    return !this.defaultPrevented;
+  }
+
+  /**
+   * @type {boolean}
+   */
+  get bubbles() {
+    if (!isEvent(this)) {
+      throw new ERR_INVALID_THIS("Event");
+    }
+    return this[kBubbles];
+  }
+
+  /**
+   * @type {boolean}
+   */
+  get composed() {
+    if (!isEvent(this)) {
+      throw new ERR_INVALID_THIS("Event");
+    }
+    return this[kComposed];
+  }
+
+  /**
+   * @type {number}
+   */
+  get eventPhase() {
+    if (!isEvent(this)) {
+      throw new ERR_INVALID_THIS("Event");
+    }
+    return this[kIsBeingDispatched] ? Event.AT_TARGET : Event.NONE;
+  }
+
+  /**
+   * @type {boolean}
+   */
+  get cancelBubble() {
+    if (!isEvent(this)) {
+      throw new ERR_INVALID_THIS("Event");
+    }
+    return this[kPropagationStopped];
+  }
+
+  /**
+   * @type {boolean}
+   */
+  set cancelBubble(value) {
+    if (!isEvent(this)) {
+      throw new ERR_INVALID_THIS("Event");
+    }
+    if (value) {
+      this.stopPropagation();
+    }
+  }
+
+  stopPropagation() {
+    if (!isEvent(this)) {
+      throw new ERR_INVALID_THIS("Event");
+    }
+    this[kPropagationStopped] = true;
+  }
+
+  static NONE = 0;
+  static CAPTURING_PHASE = 1;
+  static AT_TARGET = 2;
+  static BUBBLING_PHASE = 3;
+}
+
+Object.defineProperties(
+  Event.prototype,
+  {
+    [Symbol.toStringTag]: {
+      writable: true,
+      enumerable: false,
+      configurable: true,
+      value: "Event",
+    },
+    stopImmediatePropagation: kEnumerableProperty,
+    preventDefault: kEnumerableProperty,
+    target: kEnumerableProperty,
+    currentTarget: kEnumerableProperty,
+    srcElement: kEnumerableProperty,
+    type: kEnumerableProperty,
+    cancelable: kEnumerableProperty,
+    defaultPrevented: kEnumerableProperty,
+    timeStamp: kEnumerableProperty,
+    composedPath: kEnumerableProperty,
+    returnValue: kEnumerableProperty,
+    bubbles: kEnumerableProperty,
+    composed: kEnumerableProperty,
+    eventPhase: kEnumerableProperty,
+    cancelBubble: kEnumerableProperty,
+    stopPropagation: kEnumerableProperty,
+  },
+);
+
+function isCustomEvent(value) {
+  return isEvent(value) && (value?.[kDetail] !== undefined);
+}
+
+class CustomEvent extends Event {
+  /**
+   * @constructor
+   * @param {string} type
+   * @param {{
+   *   bubbles?: boolean,
+   *   cancelable?: boolean,
+   *   composed?: boolean,
+   *   detail?: any,
+   * }} [options]
+   */
+  constructor(type, options = kEmptyObject) {
+    if (arguments.length === 0) {
+      throw new ERR_MISSING_ARGS("type");
+    }
+    super(type, options);
+    this[kDetail] = options?.detail ?? null;
+  }
+
+  /**
+   * @type {any}
+   */
+  get detail() {
+    if (!isCustomEvent(this)) {
+      throw new ERR_INVALID_THIS("CustomEvent");
+    }
+    return this[kDetail];
+  }
+}
+
+Object.defineProperties(CustomEvent.prototype, {
+  [Symbol.toStringTag]: {
+    __proto__: null,
+    writable: false,
+    enumerable: false,
+    configurable: true,
+    value: "CustomEvent",
+  },
+  detail: kEnumerableProperty,
+});
+
+class NodeCustomEvent extends Event {
+  constructor(type, options) {
+    super(type, options);
+    if (options?.detail) {
+      this.detail = options.detail;
+    }
+  }
+}
+
+// Weak listener cleanup
+// This has to be lazy for snapshots to work
+let weakListenersState = null;
+// The resource needs to retain the callback so that it doesn't
+// get garbage collected now that it's weak.
+let objectToWeakListenerMap = null;
+function weakListeners() {
+  weakListenersState ??= new FinalizationRegistry(
+    (listener) => listener.remove(),
+  );
+  objectToWeakListenerMap ??= new WeakMap();
+  return { registry: weakListenersState, map: objectToWeakListenerMap };
+}
+
+// The listeners for an EventTarget are maintained as a linked list.
+// Unfortunately, the way EventTarget is defined, listeners are accounted
+// using the tuple [handler,capture], and even if we don't actually make
+// use of capture or bubbling, in order to be spec compliant we have to
+// take on the additional complexity of supporting it. Fortunately, using
+// the linked list makes dispatching faster, even if adding/removing is
+// slower.
+class Listener {
+  constructor(
+    previous,
+    listener,
+    once,
+    capture,
+    passive,
+    isNodeStyleListener,
+    weak,
+  ) {
+    this.next = undefined;
+    if (previous !== undefined) {
+      previous.next = this;
+    }
+    this.previous = previous;
+    this.listener = listener;
+    // TODO(benjamingr) these 4 can be 'flags' to save 3 slots
+    this.once = once;
+    this.capture = capture;
+    this.passive = passive;
+    this.isNodeStyleListener = isNodeStyleListener;
+    this.removed = false;
+    this.weak = Boolean(weak); // Don't retain the object
+
+    if (this.weak) {
+      this.callback = new WeakRef(listener);
+      weakListeners().registry.register(listener, this, this);
+      // Make the retainer retain the listener in a WeakMap
+      weakListeners().map.set(weak, listener);
+      this.listener = this.callback;
+    } else if (typeof listener === "function") {
+      this.callback = listener;
+      this.listener = listener;
+    } else {
+      this.callback = Function.prototype.bind.call(
+        listener.handleEvent,
+        listener,
+      );
+      this.listener = listener;
+    }
+  }
+
+  same(listener, capture) {
+    const myListener = this.weak ? this.listener.deref() : this.listener;
+    return myListener === listener && this.capture === capture;
+  }
+
+  remove() {
+    if (this.previous !== undefined) {
+      this.previous.next = this.next;
+    }
+    if (this.next !== undefined) {
+      this.next.previous = this.previous;
+    }
+    this.removed = true;
+    if (this.weak) {
+      weakListeners().registry.unregister(this);
+    }
+  }
+}
+
+function initEventTarget(self) {
+  self[kEvents] = new Map();
+  self[kMaxEventTargetListeners] = EventEmitter.defaultMaxListeners;
+  self[kMaxEventTargetListenersWarned] = false;
+}
+
+class EventTarget extends WebEventTarget {
+  // Used in checking whether an object is an EventTarget. This is a well-known
+  // symbol as EventTarget may be used cross-realm.
+  // Ref: https://github.com/nodejs/node/pull/33661
+  static [kIsEventTarget] = true;
+
+  constructor() {
+    super();
+    initEventTarget(this);
+  }
+
+  [kNewListener](size, type, _listener, _once, _capture, _passive, _weak) {
+    if (
+      this[kMaxEventTargetListeners] > 0 &&
+      size > this[kMaxEventTargetListeners] &&
+      !this[kMaxEventTargetListenersWarned]
+    ) {
+      this[kMaxEventTargetListenersWarned] = true;
+      // No error code for this since it is a Warning
+      // eslint-disable-next-line no-restricted-syntax
+      const w = new Error(
+        "Possible EventTarget memory leak detected. " +
+          `${size} ${type} listeners ` +
+          `added to ${inspect(this, { depth: -1 })}. Use ` +
+          "events.setMaxListeners() to increase limit",
+      );
+      w.name = "MaxListenersExceededWarning";
+      w.target = this;
+      w.type = type;
+      w.count = size;
+      emitWarning(w);
+    }
+  }
+  [kRemoveListener](_size, _type, _listener, _capture) {}
+
+  /**
+   * @callback EventTargetCallback
+   * @param {Event} event
+   */
+
+  /**
+   * @typedef {{ handleEvent: EventTargetCallback }} EventListener
+   */
+
+  /**
+   * @param {string} type
+   * @param {EventTargetCallback|EventListener} listener
+   * @param {{
+   *   capture?: boolean,
+   *   once?: boolean,
+   *   passive?: boolean,
+   *   signal?: AbortSignal
+   * }} [options]
+   */
+  addEventListener(type, listener, options = {}) {
+    if (!isEventTarget(this)) {
+      throw new ERR_INVALID_THIS("EventTarget");
+    }
+    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,
+      signal,
+      isNodeStyleListener,
+      weak,
+    } = 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;
+      emitWarning(w);
+      return;
+    }
+    type = String(type);
+
+    if (signal) {
+      if (signal.aborted) {
+        return;
+      }
+      // TODO(benjamingr) make this weak somehow? ideally the signal would
+      // not prevent the event target from GC.
+      signal.addEventListener("abort", () => {
+        this.removeEventListener(type, listener, options);
+      }, { once: true, [kWeakHandler]: this });
+    }
+
+    let root = this[kEvents].get(type);
+
+    if (root === undefined) {
+      root = { size: 1, next: undefined };
+      // This is the first handler in our linked list.
+      new Listener(
+        root,
+        listener,
+        once,
+        capture,
+        passive,
+        isNodeStyleListener,
+        weak,
+      );
+      this[kNewListener](
+        root.size,
+        type,
+        listener,
+        once,
+        capture,
+        passive,
+        weak,
+      );
+      this[kEvents].set(type, root);
+      return;
+    }
+
+    let handler = root.next;
+    let previous = root;
+
+    // We have to walk the linked list to see if we have a match
+    while (handler !== undefined && !handler.same(listener, capture)) {
+      previous = handler;
+      handler = handler.next;
+    }
+
+    if (handler !== undefined) { // Duplicate! Ignore
+      return;
+    }
+
+    new Listener(
+      previous,
+      listener,
+      once,
+      capture,
+      passive,
+      isNodeStyleListener,
+      weak,
+    );
+    root.size++;
+    this[kNewListener](root.size, type, listener, once, capture, passive, weak);
+  }
+
+  /**
+   * @param {string} type
+   * @param {EventTargetCallback|EventListener} listener
+   * @param {{
+   *   capture?: boolean,
+   * }} [options]
+   */
+  removeEventListener(type, listener, options = {}) {
+    if (!isEventTarget(this)) {
+      throw new ERR_INVALID_THIS("EventTarget");
+    }
+    if (!shouldAddListener(listener)) {
+      return;
+    }
+
+    type = String(type);
+    const capture = options?.capture === true;
+
+    const root = this[kEvents].get(type);
+    if (root === undefined || root.next === undefined) {
+      return;
+    }
+
+    let handler = root.next;
+    while (handler !== undefined) {
+      if (handler.same(listener, capture)) {
+        handler.remove();
+        root.size--;
+        if (root.size === 0) {
+          this[kEvents].delete(type);
+        }
+        this[kRemoveListener](root.size, type, listener, capture);
+        break;
+      }
+      handler = handler.next;
+    }
+  }
+
+  /**
+   * @param {Event} event
+   */
+  dispatchEvent(event) {
+    if (!isEventTarget(this)) {
+      throw new ERR_INVALID_THIS("EventTarget");
+    }
+
+    if (!(event instanceof globalThis.Event)) {
+      throw new ERR_INVALID_ARG_TYPE("event", "Event", event);
+    }
+
+    if (event[kIsBeingDispatched]) {
+      throw new ERR_EVENT_RECURSION(event.type);
+    }
+
+    this[kHybridDispatch](event, event.type, event);
+
+    return event.defaultPrevented !== true;
+  }
+
+  [kHybridDispatch](nodeValue, type, event) {
+    const createEvent = () => {
+      if (event === undefined) {
+        event = this[kCreateEvent](nodeValue, type);
+        event[kTarget] = this;
+        event[kIsBeingDispatched] = true;
+      }
+      return event;
+    };
+    if (event !== undefined) {
+      event[kTarget] = this;
+      event[kIsBeingDispatched] = true;
+    }
+
+    const root = this[kEvents].get(type);
+    if (root === undefined || root.next === undefined) {
+      if (event !== undefined) {
+        event[kIsBeingDispatched] = false;
+      }
+      return true;
+    }
+
+    let handler = root.next;
+    let next;
+
+    while (
+      handler !== undefined &&
+      (handler.passive || event?.[kStop] !== true)
+    ) {
+      // Cache the next item in case this iteration removes the current one
+      next = handler.next;
+
+      if (handler.removed) {
+        // Deal with the case an event is removed while event handlers are
+        // Being processed (removeEventListener called from a listener)
+        handler = next;
+        continue;
+      }
+      if (handler.once) {
+        handler.remove();
+        root.size--;
+        const { listener, capture } = handler;
+        this[kRemoveListener](root.size, type, listener, capture);
+      }
+
+      try {
+        let arg;
+        if (handler.isNodeStyleListener) {
+          arg = nodeValue;
+        } else {
+          arg = createEvent();
+        }
+        const callback = handler.weak
+          ? handler.callback.deref()
+          : handler.callback;
+        let result;
+        if (callback) {
+          result = callback.call(this, arg);
+          if (!handler.isNodeStyleListener) {
+            arg[kIsBeingDispatched] = false;
+          }
+        }
+        if (result !== undefined && result !== null) {
+          addCatch(result);
+        }
+      } catch (err) {
+        emitUncaughtException(err);
+      }
+
+      handler = next;
+    }
+
+    if (event !== undefined) {
+      event[kIsBeingDispatched] = false;
+    }
+  }
+
+  [kCreateEvent](nodeValue, type) {
+    return new NodeCustomEvent(type, { detail: nodeValue });
+  }
+  [customInspectSymbol](depth, options) {
+    if (!isEventTarget(this)) {
+      throw new ERR_INVALID_THIS("EventTarget");
+    }
+    const name = this.constructor.name;
+    if (depth < 0) {
+      return name;
+    }
+
+    const opts = ObjectAssign({}, options, {
+      depth: Number.isInteger(options.depth)
+        ? options.depth - 1
+        : options.depth,
+    });
+
+    return `${name} ${inspect({}, opts)}`;
+  }
+}
+
+Object.defineProperties(EventTarget.prototype, {
+  addEventListener: kEnumerableProperty,
+  removeEventListener: kEnumerableProperty,
+  dispatchEvent: kEnumerableProperty,
+  [Symbol.toStringTag]: {
+    writable: true,
+    enumerable: false,
+    configurable: true,
+    value: "EventTarget",
+  },
+});
+
+function initNodeEventTarget(self) {
+  initEventTarget(self);
+}
+
+class NodeEventTarget extends EventTarget {
+  static [kIsNodeEventTarget] = true;
+  static defaultMaxListeners = 10;
+
+  constructor() {
+    super();
+    initNodeEventTarget(this);
+  }
+
+  /**
+   * @param {number} n
+   */
+  setMaxListeners(n) {
+    if (!isNodeEventTarget(this)) {
+      throw new ERR_INVALID_THIS("NodeEventTarget");
+    }
+    EventEmitter.setMaxListeners(n, this);
+  }
+
+  /**
+   * @returns {number}
+   */
+  getMaxListeners() {
+    if (!isNodeEventTarget(this)) {
+      throw new ERR_INVALID_THIS("NodeEventTarget");
+    }
+    return this[kMaxEventTargetListeners];
+  }
+
+  /**
+   * @returns {string[]}
+   */
+  eventNames() {
+    if (!isNodeEventTarget(this)) {
+      throw new ERR_INVALID_THIS("NodeEventTarget");
+    }
+    return Array.from(this[kEvents].keys());
+  }
+
+  /**
+   * @param {string} [type]
+   * @returns {number}
+   */
+  listenerCount(type) {
+    if (!isNodeEventTarget(this)) {
+      throw new ERR_INVALID_THIS("NodeEventTarget");
+    }
+    const root = this[kEvents].get(String(type));
+    return root !== undefined ? root.size : 0;
+  }
+
+  /**
+   * @param {string} type
+   * @param {EventTargetCallback|EventListener} listener
+   * @param {{
+   *   capture?: boolean,
+   * }} [options]
+   * @returns {NodeEventTarget}
+   */
+  off(type, listener, options) {
+    if (!isNodeEventTarget(this)) {
+      throw new ERR_INVALID_THIS("NodeEventTarget");
+    }
+    this.removeEventListener(type, listener, options);
+    return this;
+  }
+
+  /**
+   * @param {string} type
+   * @param {EventTargetCallback|EventListener} listener
+   * @param {{
+   *   capture?: boolean,
+   * }} [options]
+   * @returns {NodeEventTarget}
+   */
+  removeListener(type, listener, options) {
+    if (!isNodeEventTarget(this)) {
+      throw new ERR_INVALID_THIS("NodeEventTarget");
+    }
+    this.removeEventListener(type, listener, options);
+    return this;
+  }
+
+  /**
+   * @param {string} type
+   * @param {EventTargetCallback|EventListener} listener
+   * @returns {NodeEventTarget}
+   */
+  on(type, listener) {
+    if (!isNodeEventTarget(this)) {
+      throw new ERR_INVALID_THIS("NodeEventTarget");
+    }
+    this.addEventListener(type, listener, { [kIsNodeStyleListener]: true });
+    return this;
+  }
+
+  /**
+   * @param {string} type
+   * @param {EventTargetCallback|EventListener} listener
+   * @returns {NodeEventTarget}
+   */
+  addListener(type, listener) {
+    if (!isNodeEventTarget(this)) {
+      throw new ERR_INVALID_THIS("NodeEventTarget");
+    }
+    this.addEventListener(type, listener, { [kIsNodeStyleListener]: true });
+    return this;
+  }
+
+  /**
+   * @param {string} type
+   * @param {any} arg
+   * @returns {boolean}
+   */
+  emit(type, arg) {
+    if (!isNodeEventTarget(this)) {
+      throw new ERR_INVALID_THIS("NodeEventTarget");
+    }
+    validateString(type, "type");
+    const hadListeners = this.listenerCount(type) > 0;
+    this[kHybridDispatch](arg, type);
+    return hadListeners;
+  }
+
+  /**
+   * @param {string} type
+   * @param {EventTargetCallback|EventListener} listener
+   * @returns {NodeEventTarget}
+   */
+  once(type, listener) {
+    if (!isNodeEventTarget(this)) {
+      throw new ERR_INVALID_THIS("NodeEventTarget");
+    }
+    this.addEventListener(type, listener, {
+      once: true,
+      [kIsNodeStyleListener]: true,
+    });
+    return this;
+  }
+
+  /**
+   * @param {string} type
+   * @returns {NodeEventTarget}
+   */
+  removeAllListeners(type) {
+    if (!isNodeEventTarget(this)) {
+      throw new ERR_INVALID_THIS("NodeEventTarget");
+    }
+    if (type !== undefined) {
+      this[kEvents].delete(String(type));
+    } else {
+      this[kEvents].clear();
+    }
+
+    return this;
+  }
+}
+
+Object.defineProperties(NodeEventTarget.prototype, {
+  setMaxListeners: kEnumerableProperty,
+  getMaxListeners: kEnumerableProperty,
+  eventNames: kEnumerableProperty,
+  listenerCount: kEnumerableProperty,
+  off: kEnumerableProperty,
+  removeListener: kEnumerableProperty,
+  on: kEnumerableProperty,
+  addListener: kEnumerableProperty,
+  once: kEnumerableProperty,
+  emit: kEnumerableProperty,
+  removeAllListeners: kEnumerableProperty,
+});
+
+// EventTarget API
+
+function shouldAddListener(listener) {
+  if (
+    typeof listener === "function" ||
+    typeof listener?.handleEvent === "function"
+  ) {
+    return true;
+  }
+
+  if (listener == null) {
+    return false;
+  }
+
+  throw new ERR_INVALID_ARG_TYPE("listener", "EventListener", listener);
+}
+
+function validateEventListenerOptions(options) {
+  if (typeof options === "boolean") {
+    return { capture: options };
+  }
+
+  if (options === null) {
+    return {};
+  }
+  validateObject(options, "options", {
+    allowArray: true,
+    allowFunction: true,
+  });
+  return {
+    once: Boolean(options.once),
+    capture: Boolean(options.capture),
+    passive: Boolean(options.passive),
+    signal: options.signal,
+    weak: options[kWeakHandler],
+    isNodeStyleListener: Boolean(options[kIsNodeStyleListener]),
+  };
+}
+
+function isEventTarget(obj) {
+  return obj instanceof globalThis.EventTarget;
+}
+
+function isNodeEventTarget(obj) {
+  return obj?.constructor?.[kIsNodeEventTarget];
+}
+
+function addCatch(promise) {
+  const then = promise.then;
+  if (typeof then === "function") {
+    then.call(promise, undefined, function (err) {
+      // The callback is called with nextTick to avoid a follow-up
+      // rejection from this promise.
+      emitUncaughtException(err);
+    });
+  }
+}
+
+function emitUncaughtException(err) {
+  nextTick(() => {
+    throw err;
+  });
+}
+
+function makeEventHandler(handler) {
+  // Event handlers are dispatched in the order they were first set
+  // See https://github.com/nodejs/node/pull/35949#issuecomment-722496598
+  function eventHandler(...args) {
+    if (typeof eventHandler.handler !== "function") {
+      return;
+    }
+    return Reflect.apply(eventHandler.handler, this, args);
+  }
+  eventHandler.handler = handler;
+  return eventHandler;
+}
+
+function defineEventHandler(emitter, name) {
+  // 8.1.5.1 Event handlers - basically `on[eventName]` attributes
+  Object.defineProperty(emitter, `on${name}`, {
+    get() {
+      return this[kHandlers]?.get(name)?.handler ?? null;
+    },
+    set(value) {
+      if (!this[kHandlers]) {
+        this[kHandlers] = new Map();
+      }
+      let wrappedHandler = this[kHandlers]?.get(name);
+      if (wrappedHandler) {
+        if (typeof wrappedHandler.handler === "function") {
+          this[kEvents].get(name).size--;
+          const size = this[kEvents].get(name).size;
+          this[kRemoveListener](size, name, wrappedHandler.handler, false);
+        }
+        wrappedHandler.handler = value;
+        if (typeof wrappedHandler.handler === "function") {
+          this[kEvents].get(name).size++;
+          const size = this[kEvents].get(name).size;
+          this[kNewListener](size, name, value, false, false, false, false);
+        }
+      } else {
+        wrappedHandler = makeEventHandler(value);
+        this.addEventListener(name, wrappedHandler);
+      }
+      this[kHandlers].set(name, wrappedHandler);
+    },
+    configurable: true,
+    enumerable: true,
+  });
+}
+
+const EventEmitterMixin = (Superclass) => {
+  class MixedEventEmitter extends Superclass {
+    constructor(...args) {
+      super(...args);
+      EventEmitter.call(this);
+    }
+  }
+  const protoProps = Object.getOwnPropertyDescriptors(EventEmitter.prototype);
+  delete protoProps.constructor;
+  Object.defineProperties(MixedEventEmitter.prototype, protoProps);
+  return MixedEventEmitter;
+};
+
+export {
+  CustomEvent,
+  defineEventHandler,
+  Event,
+  EventEmitterMixin,
+  EventTarget,
+  initEventTarget,
+  initNodeEventTarget,
+  isEventTarget,
+  kCreateEvent,
+  kEvents,
+  kNewListener,
+  kRemoveListener,
+  kTrustEvent,
+  kWeakHandler,
+  NodeEventTarget,
+};
+
+export default {
+  CustomEvent,
+  Event,
+  EventEmitterMixin,
+  EventTarget,
+  NodeEventTarget,
+  defineEventHandler,
+  initEventTarget,
+  initNodeEventTarget,
+  kCreateEvent,
+  kNewListener,
+  kTrustEvent,
+  kRemoveListener,
+  kEvents,
+  kWeakHandler,
+  isEventTarget,
+};