diff --git a/2015/InstanceofOperator.js b/2015/InstanceofOperator.js
index adb8127f..d940cd6e 100644
--- a/2015/InstanceofOperator.js
+++ b/2015/InstanceofOperator.js
@@ -4,7 +4,7 @@ var GetIntrinsic = require('get-intrinsic');
 
 var $TypeError = require('es-errors/type');
 
-var $hasInstance = GetIntrinsic('Symbol.hasInstance', true);
+var $hasInstance = GetIntrinsic('%Symbol.hasInstance%', true);
 
 var Call = require('./Call');
 var GetMethod = require('./GetMethod');
diff --git a/2016/InstanceofOperator.js b/2016/InstanceofOperator.js
index adb8127f..d940cd6e 100644
--- a/2016/InstanceofOperator.js
+++ b/2016/InstanceofOperator.js
@@ -4,7 +4,7 @@ var GetIntrinsic = require('get-intrinsic');
 
 var $TypeError = require('es-errors/type');
 
-var $hasInstance = GetIntrinsic('Symbol.hasInstance', true);
+var $hasInstance = GetIntrinsic('%Symbol.hasInstance%', true);
 
 var Call = require('./Call');
 var GetMethod = require('./GetMethod');
diff --git a/2017/InstanceofOperator.js b/2017/InstanceofOperator.js
index adb8127f..d940cd6e 100644
--- a/2017/InstanceofOperator.js
+++ b/2017/InstanceofOperator.js
@@ -4,7 +4,7 @@ var GetIntrinsic = require('get-intrinsic');
 
 var $TypeError = require('es-errors/type');
 
-var $hasInstance = GetIntrinsic('Symbol.hasInstance', true);
+var $hasInstance = GetIntrinsic('%Symbol.hasInstance%', true);
 
 var Call = require('./Call');
 var GetMethod = require('./GetMethod');
diff --git a/2018/InstanceofOperator.js b/2018/InstanceofOperator.js
index adb8127f..d940cd6e 100644
--- a/2018/InstanceofOperator.js
+++ b/2018/InstanceofOperator.js
@@ -4,7 +4,7 @@ var GetIntrinsic = require('get-intrinsic');
 
 var $TypeError = require('es-errors/type');
 
-var $hasInstance = GetIntrinsic('Symbol.hasInstance', true);
+var $hasInstance = GetIntrinsic('%Symbol.hasInstance%', true);
 
 var Call = require('./Call');
 var GetMethod = require('./GetMethod');
diff --git a/2019/InstanceofOperator.js b/2019/InstanceofOperator.js
index adb8127f..d940cd6e 100644
--- a/2019/InstanceofOperator.js
+++ b/2019/InstanceofOperator.js
@@ -4,7 +4,7 @@ var GetIntrinsic = require('get-intrinsic');
 
 var $TypeError = require('es-errors/type');
 
-var $hasInstance = GetIntrinsic('Symbol.hasInstance', true);
+var $hasInstance = GetIntrinsic('%Symbol.hasInstance%', true);
 
 var Call = require('./Call');
 var GetMethod = require('./GetMethod');
diff --git a/2020/InstanceofOperator.js b/2020/InstanceofOperator.js
index adb8127f..d940cd6e 100644
--- a/2020/InstanceofOperator.js
+++ b/2020/InstanceofOperator.js
@@ -4,7 +4,7 @@ var GetIntrinsic = require('get-intrinsic');
 
 var $TypeError = require('es-errors/type');
 
-var $hasInstance = GetIntrinsic('Symbol.hasInstance', true);
+var $hasInstance = GetIntrinsic('%Symbol.hasInstance%', true);
 
 var Call = require('./Call');
 var GetMethod = require('./GetMethod');
diff --git a/2021/InstanceofOperator.js b/2021/InstanceofOperator.js
index adb8127f..d940cd6e 100644
--- a/2021/InstanceofOperator.js
+++ b/2021/InstanceofOperator.js
@@ -4,7 +4,7 @@ var GetIntrinsic = require('get-intrinsic');
 
 var $TypeError = require('es-errors/type');
 
-var $hasInstance = GetIntrinsic('Symbol.hasInstance', true);
+var $hasInstance = GetIntrinsic('%Symbol.hasInstance%', true);
 
 var Call = require('./Call');
 var GetMethod = require('./GetMethod');
diff --git a/2022/InstanceofOperator.js b/2022/InstanceofOperator.js
index adb8127f..d940cd6e 100644
--- a/2022/InstanceofOperator.js
+++ b/2022/InstanceofOperator.js
@@ -4,7 +4,7 @@ var GetIntrinsic = require('get-intrinsic');
 
 var $TypeError = require('es-errors/type');
 
-var $hasInstance = GetIntrinsic('Symbol.hasInstance', true);
+var $hasInstance = GetIntrinsic('%Symbol.hasInstance%', true);
 
 var Call = require('./Call');
 var GetMethod = require('./GetMethod');
diff --git a/2022/TypedArrayElementSize.js b/2022/TypedArrayElementSize.js
index ea4f95f2..2cc3ce39 100644
--- a/2022/TypedArrayElementSize.js
+++ b/2022/TypedArrayElementSize.js
@@ -13,7 +13,7 @@ var tableTAO = require('./tables/typed-array-objects');
 
 module.exports = function TypedArrayElementSize(O) {
 	var type = whichTypedArray(O);
-	if (type === false) {
+	if (!type) {
 		throw new $TypeError('Assertion failed: `O` must be a TypedArray');
 	}
 	var size = tableTAO.size['$' + tableTAO.name['$' + type]];
diff --git a/2022/TypedArrayElementType.js b/2022/TypedArrayElementType.js
index 103976ac..0e9abe6a 100644
--- a/2022/TypedArrayElementType.js
+++ b/2022/TypedArrayElementType.js
@@ -11,7 +11,7 @@ var tableTAO = require('./tables/typed-array-objects');
 
 module.exports = function TypedArrayElementType(O) {
 	var type = whichTypedArray(O);
-	if (type === false) {
+	if (!type) {
 		throw new $TypeError('Assertion failed: `O` must be a TypedArray');
 	}
 	var result = tableTAO.name['$' + type];
diff --git a/2023/FindViaPredicate.js b/2023/FindViaPredicate.js
index d72ec454..a1c46947 100644
--- a/2023/FindViaPredicate.js
+++ b/2023/FindViaPredicate.js
@@ -11,6 +11,8 @@ var ToString = require('./ToString');
 var isInteger = require('../helpers/isInteger');
 var isObject = require('../helpers/isObject');
 
+// https://262.ecma-international.org/14.0/#sec-findviapredicate
+
 module.exports = function FindViaPredicate(O, len, direction, predicate, thisArg) {
 	if (!isObject(O)) {
 		throw new $TypeError('Assertion failed: Type(O) is not Object');
diff --git a/2023/InstanceofOperator.js b/2023/InstanceofOperator.js
index adb8127f..d940cd6e 100644
--- a/2023/InstanceofOperator.js
+++ b/2023/InstanceofOperator.js
@@ -4,7 +4,7 @@ var GetIntrinsic = require('get-intrinsic');
 
 var $TypeError = require('es-errors/type');
 
-var $hasInstance = GetIntrinsic('Symbol.hasInstance', true);
+var $hasInstance = GetIntrinsic('%Symbol.hasInstance%', true);
 
 var Call = require('./Call');
 var GetMethod = require('./GetMethod');
diff --git a/2023/TypedArrayElementSize.js b/2023/TypedArrayElementSize.js
index ea4f95f2..2cc3ce39 100644
--- a/2023/TypedArrayElementSize.js
+++ b/2023/TypedArrayElementSize.js
@@ -13,7 +13,7 @@ var tableTAO = require('./tables/typed-array-objects');
 
 module.exports = function TypedArrayElementSize(O) {
 	var type = whichTypedArray(O);
-	if (type === false) {
+	if (!type) {
 		throw new $TypeError('Assertion failed: `O` must be a TypedArray');
 	}
 	var size = tableTAO.size['$' + tableTAO.name['$' + type]];
diff --git a/2023/TypedArrayElementType.js b/2023/TypedArrayElementType.js
index 103976ac..0e9abe6a 100644
--- a/2023/TypedArrayElementType.js
+++ b/2023/TypedArrayElementType.js
@@ -11,7 +11,7 @@ var tableTAO = require('./tables/typed-array-objects');
 
 module.exports = function TypedArrayElementType(O) {
 	var type = whichTypedArray(O);
-	if (type === false) {
+	if (!type) {
 		throw new $TypeError('Assertion failed: `O` must be a TypedArray');
 	}
 	var result = tableTAO.name['$' + type];
diff --git a/2024/FindViaPredicate.js b/2024/FindViaPredicate.js
index 24e3ecdd..21247221 100644
--- a/2024/FindViaPredicate.js
+++ b/2024/FindViaPredicate.js
@@ -11,6 +11,8 @@ var ToString = require('./ToString');
 var isInteger = require('../helpers/isInteger');
 var isObject = require('../helpers/isObject');
 
+// https://262.ecma-international.org/15.0/#sec-findviapredicate
+
 module.exports = function FindViaPredicate(O, len, direction, predicate, thisArg) {
 	if (!isObject(O)) {
 		throw new $TypeError('Assertion failed: Type(O) is not Object');
diff --git a/2024/GroupBy.js b/2024/GroupBy.js
index 95b03648..e91787c4 100644
--- a/2024/GroupBy.js
+++ b/2024/GroupBy.js
@@ -39,7 +39,8 @@ module.exports = function GroupBy(items, callbackfn, keyCoercion) {
 	while (true) { // step 6
 		if (k >= maxSafeInteger) { // step 6.a
 			var error = ThrowCompletion(new $TypeError('k must be less than 2 ** 53 - 1')); // step 6.a.i
-			return IteratorClose(iteratorRecord, error); // step 6.a.ii
+			IteratorClose(iteratorRecord, error); // step 6.a.ii
+			return void undefined;
 		}
 		var next = IteratorStep(iteratorRecord); // step 6.b
 		if (!next) { // step 6.c
@@ -52,14 +53,16 @@ module.exports = function GroupBy(items, callbackfn, keyCoercion) {
 		try {
 			key = Call(callbackfn, undefined, [value, k]); // step 6.e
 		} catch (e) {
-			return IteratorClose(iteratorRecord, ThrowCompletion(e)); // step 6.f
+			IteratorClose(iteratorRecord, ThrowCompletion(e)); // step 6.f
+			return void undefined;
 		}
 
 		if (keyCoercion === 'PROPERTY') { // step 6.g
 			try {
 				key = ToPropertyKey(key); // step 6.g.i
 			} catch (e) {
-				return IteratorClose(iteratorRecord, ThrowCompletion(e)); // step 6.g.ii
+				IteratorClose(iteratorRecord, ThrowCompletion(e)); // step 6.g.ii
+				return void undefined;
 			}
 		} else { // step 6.h
 			if (keyCoercion !== 'ZERO') {
diff --git a/2024/InstanceofOperator.js b/2024/InstanceofOperator.js
index adb8127f..d940cd6e 100644
--- a/2024/InstanceofOperator.js
+++ b/2024/InstanceofOperator.js
@@ -4,7 +4,7 @@ var GetIntrinsic = require('get-intrinsic');
 
 var $TypeError = require('es-errors/type');
 
-var $hasInstance = GetIntrinsic('Symbol.hasInstance', true);
+var $hasInstance = GetIntrinsic('%Symbol.hasInstance%', true);
 
 var Call = require('./Call');
 var GetMethod = require('./GetMethod');
diff --git a/2024/SetValueInBuffer.js b/2024/SetValueInBuffer.js
index a706720b..44d11b29 100644
--- a/2024/SetValueInBuffer.js
+++ b/2024/SetValueInBuffer.js
@@ -14,7 +14,7 @@ var NumericToRawBytes = require('./NumericToRawBytes');
 
 var isArrayBuffer = require('is-array-buffer');
 var isSharedArrayBuffer = require('is-shared-array-buffer');
-var has = require('hasown');
+var hasOwn = require('hasown');
 
 var tableTAO = require('./tables/typed-array-objects');
 
@@ -35,7 +35,7 @@ module.exports = function SetValueInBuffer(arrayBuffer, byteIndex, type, value,
 		throw new $TypeError('Assertion failed: `byteIndex` must be a non-negative integer');
 	}
 
-	if (typeof type !== 'string' || !has(tableTAO.size, '$' + type)) {
+	if (typeof type !== 'string' || !hasOwn(tableTAO.size, '$' + type)) {
 		throw new $TypeError('Assertion failed: `type` must be a Typed Array Element Type');
 	}
 
diff --git a/2024/ThisBigIntValue.js b/2024/ThisBigIntValue.js
index 252f9553..7b479349 100644
--- a/2024/ThisBigIntValue.js
+++ b/2024/ThisBigIntValue.js
@@ -9,10 +9,12 @@ var $bigIntValueOf = callBound('BigInt.prototype.valueOf', true);
 
 module.exports = function ThisBigIntValue(value) {
 	if (typeof value === 'bigint') {
-		return value; // step 1
+		return value;
 	}
+
 	if (!$bigIntValueOf) {
 		throw new $SyntaxError('BigInt is not supported');
 	}
+
 	return $bigIntValueOf(value);
 };
diff --git a/2024/TypedArrayElementSize.js b/2024/TypedArrayElementSize.js
index ea4f95f2..2cc3ce39 100644
--- a/2024/TypedArrayElementSize.js
+++ b/2024/TypedArrayElementSize.js
@@ -13,7 +13,7 @@ var tableTAO = require('./tables/typed-array-objects');
 
 module.exports = function TypedArrayElementSize(O) {
 	var type = whichTypedArray(O);
-	if (type === false) {
+	if (!type) {
 		throw new $TypeError('Assertion failed: `O` must be a TypedArray');
 	}
 	var size = tableTAO.size['$' + tableTAO.name['$' + type]];
diff --git a/2024/TypedArrayElementType.js b/2024/TypedArrayElementType.js
index 103976ac..0e9abe6a 100644
--- a/2024/TypedArrayElementType.js
+++ b/2024/TypedArrayElementType.js
@@ -11,7 +11,7 @@ var tableTAO = require('./tables/typed-array-objects');
 
 module.exports = function TypedArrayElementType(O) {
 	var type = whichTypedArray(O);
-	if (type === false) {
+	if (!type) {
 		throw new $TypeError('Assertion failed: `O` must be a TypedArray');
 	}
 	var result = tableTAO.name['$' + type];
diff --git a/helpers/isFullyPopulatedPropertyDescriptor.js b/helpers/isFullyPopulatedPropertyDescriptor.js
index e75f33f7..227860ef 100644
--- a/helpers/isFullyPopulatedPropertyDescriptor.js
+++ b/helpers/isFullyPopulatedPropertyDescriptor.js
@@ -4,7 +4,6 @@ var isPropertyDescriptor = require('./records/property-descriptor');
 
 module.exports = function isFullyPopulatedPropertyDescriptor(ES, Desc) {
 	return isPropertyDescriptor(Desc)
-		&& typeof Desc === 'object'
 		&& '[[Enumerable]]' in Desc
 		&& '[[Configurable]]' in Desc
 		&& (ES.IsAccessorDescriptor(Desc) || ES.IsDataDescriptor(Desc));
diff --git a/helpers/isObject.js b/helpers/isObject.js
index 620243f2..10469eef 100644
--- a/helpers/isObject.js
+++ b/helpers/isObject.js
@@ -1,5 +1,5 @@
 'use strict';
 
 module.exports = function isObject(x) {
-	return x && (typeof x === 'function' || typeof x === 'object');
+	return !!x && (typeof x === 'function' || typeof x === 'object');
 };