nodejs
diff --git a/‎lib/internal/event_target.js‎
Lines changed: 3 additions & 2 deletions b/‎lib/internal/event_target.js‎
Lines changed: 3 additions & 2 deletions
diff --git a/‎lib/internal/webidl.js‎
Lines changed: 180 additions & 0 deletions b/‎lib/internal/webidl.js‎
Lines changed: 180 additions & 0 deletions
diff --git a/‎test/parallel/test-bootstrap-modules.js‎
Lines changed: 1 addition & 0 deletions b/‎test/parallel/test-bootstrap-modules.js‎
Lines changed: 1 addition & 0 deletions
diff --git a/‎test/parallel/test-eventtarget.js‎
Lines changed: 12 additions & 0 deletions b/‎test/parallel/test-eventtarget.js‎
Lines changed: 12 additions & 0 deletions
@@ -42,6 +42,7 @@ const {
   kEnumerableProperty,
 } = require('internal/util');
 const { inspect } = require('util');
+const webidl = require('internal/webidl');
 
 const kIsEventTarget = SymbolFor('nodejs.event_target');
 const kIsNodeEventTarget = Symbol('kIsNodeEventTarget');
@@ -577,7 +578,7 @@ class EventTarget {
       process.emitWarning(w);
       return;
     }
-    type = String(type);
+    type = webidl.converters.DOMString(type);
 
     if (signal) {
       if (signal.aborted) {
@@ -643,7 +644,7 @@ class EventTarget {
     if (!validateEventListener(listener))
       return;
 
-    type = String(type);
+    type = webidl.converters.DOMString(type);
     const capture = options?.capture === true;
 
     const root = this[kEvents].get(type);
 
@@ -0,0 +1,180 @@
+'use strict';
+
+const {
+  MathAbs,
+  MathMax,
+  MathMin,
+  MathPow,
+  MathSign,
+  MathTrunc,
+  NumberIsNaN,
+  NumberMAX_SAFE_INTEGER,
+  NumberMIN_SAFE_INTEGER,
+  String,
+} = primordials;
+
+const {
+  codes: {
+    ERR_INVALID_ARG_VALUE,
+  },
+} = require('internal/errors');
+const { kEmptyObject } = require('internal/util');
+
+const converters = { __proto__: null };
+
+// https://webidl.spec.whatwg.org/#abstract-opdef-integerpart
+const integerPart = MathTrunc;
+
+/* eslint-disable node-core/non-ascii-character */
+// Round x to the nearest integer, choosing the even integer if it lies halfway
+// between two, and choosing +0 rather than -0.
+// This is different from Math.round, which rounds to the next integer in the
+// direction of +∞ when the fraction portion is exactly 0.5.
+/* eslint-enable node-core/non-ascii-character */
+function evenRound(x) {
+  // Convert -0 to +0.
+  const i = integerPart(x) + 0;
+  const reminder = MathAbs(x % 1);
+  const sign = MathSign(i);
+  if (reminder === 0.5) {
+    return i % 2 === 0 ? i : i + sign;
+  }
+  const r = reminder < 0.5 ? i : i + sign;
+  // Convert -0 to +0.
+  if (r === 0) {
+    return 0;
+  }
+  return r;
+}
+
+function pow2(exponent) {
+  // << operates on 32 bit signed integers.
+  if (exponent < 31) {
+    return 1 << exponent;
+  }
+  if (exponent === 31) {
+    return 0x8000_0000;
+  }
+  if (exponent === 32) {
+    return 0x1_0000_0000;
+  }
+  return MathPow(2, exponent);
+}
+
+// https://tc39.es/ecma262/#eqn-modulo
+// The notation “x modulo y” computes a value k of the same sign as y.
+function modulo(x, y) {
+  const r = x % y;
+  // Convert -0 to +0.
+  if (r === 0) {
+    return 0;
+  }
+  return r;
+}
+
+// https://webidl.spec.whatwg.org/#abstract-opdef-converttoint
+function convertToInt(name, value, bitLength, options = kEmptyObject) {
+  const { signed = false, enforceRange = false, clamp = false } = options;
+
+  let upperBound;
+  let lowerBound;
+  // 1. If bitLength is 64, then:
+  if (bitLength === 64) {
+    // 1.1. Let upperBound be 2^53 − 1.
+    upperBound = NumberMAX_SAFE_INTEGER;
+    // 1.2. If signedness is "unsigned", then let lowerBound be 0.
+    // 1.3. Otherwise let lowerBound be −2^53 + 1.
+    lowerBound = !signed ? 0 : NumberMIN_SAFE_INTEGER;
+  } else if (!signed) {
+    // 2. Otherwise, if signedness is "unsigned", then:
+    // 2.1. Let lowerBound be 0.
+    // 2.2. Let upperBound be 2^bitLength − 1.
+    lowerBound = 0;
+    upperBound = pow2(bitLength) - 1;
+  } else {
+    // 3. Otherwise:
+    // 3.1. Let lowerBound be -2^(bitLength − 1).
+    // 3.2. Let upperBound be 2^(bitLength − 1) − 1.
+    lowerBound = -pow2(bitLength - 1);
+    upperBound = pow2(bitLength - 1) - 1;
+  }
+
+  // 4. Let x be ? ToNumber(V).
+  let x = +value;
+  // 5. If x is −0, then set x to +0.
+  if (x === 0) {
+    x = 0;
+  }
+
+  // 6. If the conversion is to an IDL type associated with the [EnforceRange]
+  // extended attribute, then:
+  if (enforceRange) {
+    // 6.1. If x is NaN, +∞, or −∞, then throw a TypeError.
+    if (NumberIsNaN(x) || x === Infinity || x === -Infinity) {
+      throw new ERR_INVALID_ARG_VALUE(name, x);
+    }
+    // 6.2. Set x to IntegerPart(x).
+    x = integerPart(x);
+
+    // 6.3. If x < lowerBound or x > upperBound, then throw a TypeError.
+    if (x < lowerBound || x > upperBound) {
+      throw new ERR_INVALID_ARG_VALUE(name, x);
+    }
+
+    // 6.4. Return x.
+    return x;
+  }
+
+  // 7. If x is not NaN and the conversion is to an IDL type associated with
+  // the [Clamp] extended attribute, then:
+  if (clamp && !NumberIsNaN(x)) {
+    // 7.1. Set x to min(max(x, lowerBound), upperBound).
+    x = MathMin(MathMax(x, lowerBound), upperBound);
+
+    // 7.2. Round x to the nearest integer, choosing the even integer if it
+    // lies halfway between two, and choosing +0 rather than −0.
+    x = evenRound(x);
+
+    // 7.3. Return x.
+    return x;
+  }
+
+  // 8. If x is NaN, +0, +∞, or −∞, then return +0.
+  if (NumberIsNaN(x) || x === 0 || x === Infinity || x === -Infinity) {
+    return 0;
+  }
+
+  // 9. Set x to IntegerPart(x).
+  x = integerPart(x);
+
+  // 10. Set x to x modulo 2^bitLength.
+  x = modulo(x, pow2(bitLength));
+
+  // 11. If signedness is "signed" and x ≥ 2^(bitLength − 1), then return x −
+  // 2^bitLength.
+  if (signed && x >= pow2(bitLength - 1)) {
+    return x - pow2(bitLength);
+  }
+
+  // 12. Otherwise, return x.
+  return x;
+}
+
+/**
+ * @see https://webidl.spec.whatwg.org/#es-DOMString
+ * @param {any} V
+ * @returns {string}
+ */
+converters.DOMString = function DOMString(V) {
+  if (typeof V === 'symbol') {
+    throw new ERR_INVALID_ARG_VALUE('value', V);
+  }
+
+  return String(V);
+};
+
+module.exports = {
+  convertToInt,
+  evenRound,
+  converters,
+};
@@ -151,6 +151,7 @@ const expectedModules = new Set([
   'NativeModule internal/vm',
   'NativeModule internal/vm/module',
   'NativeModule internal/wasm_web_api',
+  'NativeModule internal/webidl',
   'NativeModule internal/webstreams/adapters',
   'NativeModule internal/webstreams/compression',
   'NativeModule internal/webstreams/encoding',
 
@@ -705,3 +705,15 @@ let asyncTest = Promise.resolve();
     name: 'TypeError',
   });
 }
+
+{
+  const et = new EventTarget();
+
+  throws(() => {
+    et.addEventListener(Symbol('symbol'), () => {});
+  }, TypeError);
+
+  throws(() => {
+    et.removeEventListener(Symbol('symbol'), () => {});
+  }, TypeError);
+}