From 039cd353f1dad9d3a567d5c2e34e3a2bfe44cf64 Mon Sep 17 00:00:00 2001
From: Linus Groh <mail@linusgroh.de>
Date: Fri, 27 Jan 2023 21:24:21 +0000
Subject: [PATCH] LibJS: Implement the thisBooleanValue AO and use it in
 BooleanPrototype

---
 .../LibJS/Runtime/BooleanPrototype.cpp        | 40 ++++++++++++-------
 1 file changed, 26 insertions(+), 14 deletions(-)

diff --git a/Userland/Libraries/LibJS/Runtime/BooleanPrototype.cpp b/Userland/Libraries/LibJS/Runtime/BooleanPrototype.cpp
index 0a8f85c3a0c..bb89ba895d0 100644
--- a/Userland/Libraries/LibJS/Runtime/BooleanPrototype.cpp
+++ b/Userland/Libraries/LibJS/Runtime/BooleanPrototype.cpp
@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2020, Jack Karamanian <karamanian.jack@gmail.com>
+ * Copyright (c) 2021-2023, Linus Groh <linusg@serenityos.org>
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
@@ -26,29 +27,40 @@ void BooleanPrototype::initialize(Realm& realm)
     define_native_function(realm, vm.names.valueOf, value_of, 0, attr);
 }
 
+// thisBooleanValue ( value ), https://tc39.es/ecma262/#thisbooleanvalue
+static ThrowCompletionOr<bool> this_boolean_value(VM& vm, Value value)
+{
+    // 1. If value is a Boolean, return value.
+    if (value.is_boolean())
+        return value.as_bool();
+
+    // 2. If value is an Object and value has a [[BooleanData]] internal slot, then
+    if (value.is_object() && is<BooleanObject>(value.as_object())) {
+        // a. Let b be value.[[BooleanData]].
+        // b. Assert: b is a Boolean.
+        // c. Return b.
+        return static_cast<BooleanObject&>(value.as_object()).boolean();
+    }
+
+    // 3. Throw a TypeError exception.
+    return vm.throw_completion<TypeError>(ErrorType::NotAnObjectOfType, "Boolean");
+}
+
 // 20.3.3.2 Boolean.prototype.toString ( ), https://tc39.es/ecma262/#sec-boolean.prototype.tostring
 JS_DEFINE_NATIVE_FUNCTION(BooleanPrototype::to_string)
 {
-    auto this_value = vm.this_value();
-    if (this_value.is_boolean())
-        return PrimitiveString::create(vm, this_value.as_bool() ? "true" : "false");
-    if (!this_value.is_object() || !is<BooleanObject>(this_value.as_object()))
-        return vm.throw_completion<TypeError>(ErrorType::NotAnObjectOfType, "Boolean");
+    // 1. Let b be ? thisBooleanValue(this value).
+    auto b = TRY(this_boolean_value(vm, vm.this_value()));
 
-    bool bool_value = static_cast<BooleanObject const&>(this_value.as_object()).boolean();
-    return PrimitiveString::create(vm, bool_value ? "true" : "false");
+    // 2. If b is true, return "true"; else return "false".
+    return PrimitiveString::create(vm, TRY_OR_THROW_OOM(vm, String::from_utf8(b ? "true"sv : "false"sv)));
 }
 
 // 20.3.3.3 Boolean.prototype.valueOf ( ), https://tc39.es/ecma262/#sec-boolean.prototype.valueof
 JS_DEFINE_NATIVE_FUNCTION(BooleanPrototype::value_of)
 {
-    auto this_value = vm.this_value();
-    if (this_value.is_boolean())
-        return this_value;
-    if (!this_value.is_object() || !is<BooleanObject>(this_value.as_object()))
-        return vm.throw_completion<TypeError>(ErrorType::NotAnObjectOfType, "Boolean");
-
-    return Value(static_cast<BooleanObject const&>(this_value.as_object()).boolean());
+    // 1. Return ? thisBooleanValue(this value).
+    return TRY(this_boolean_value(vm, vm.this_value()));
 }
 
 }