From 66c31a0c07b6ad73c096c6d4553c0dbd3385baf7 Mon Sep 17 00:00:00 2001
From: Timothy Flynn <trflynn89@pm.me>
Date: Thu, 22 Jul 2021 10:22:07 -0400
Subject: [PATCH] LibJS: Implement RegExp.prototype [ @@search ] with UTF-16
 code units

---
 .../LibJS/Runtime/RegExpPrototype.cpp         |  8 ++++----
 .../LibJS/Runtime/StringPrototype.cpp         |  7 +++++--
 .../String/String.prototype.search.js         | 19 ++++++++++++-------
 3 files changed, 21 insertions(+), 13 deletions(-)

diff --git a/Userland/Libraries/LibJS/Runtime/RegExpPrototype.cpp b/Userland/Libraries/LibJS/Runtime/RegExpPrototype.cpp
index 5373735c0d..a80d94efa5 100644
--- a/Userland/Libraries/LibJS/Runtime/RegExpPrototype.cpp
+++ b/Userland/Libraries/LibJS/Runtime/RegExpPrototype.cpp
@@ -787,14 +787,14 @@ JS_DEFINE_NATIVE_FUNCTION(RegExpPrototype::symbol_replace)
 // 22.2.5.11 RegExp.prototype [ @@search ] ( string ), https://tc39.es/ecma262/#sec-regexp.prototype-@@search
 JS_DEFINE_NATIVE_FUNCTION(RegExpPrototype::symbol_search)
 {
-    auto string_value = vm.argument(0);
-
     auto* regexp_object = this_object_from(vm, global_object);
     if (!regexp_object)
         return {};
-    auto string = string_value.to_string(global_object);
+
+    auto string = vm.argument(0).to_utf16_string(global_object);
     if (vm.exception())
         return {};
+    Utf16View string_view { string };
 
     auto previous_last_index = regexp_object->get(vm.names.lastIndex);
     if (vm.exception())
@@ -805,7 +805,7 @@ JS_DEFINE_NATIVE_FUNCTION(RegExpPrototype::symbol_search)
             return {};
     }
 
-    auto result = regexp_exec(global_object, *regexp_object, string);
+    auto result = regexp_exec(global_object, *regexp_object, string_view);
     if (vm.exception())
         return {};
 
diff --git a/Userland/Libraries/LibJS/Runtime/StringPrototype.cpp b/Userland/Libraries/LibJS/Runtime/StringPrototype.cpp
index 549d82e508..dda7cd91ed 100644
--- a/Userland/Libraries/LibJS/Runtime/StringPrototype.cpp
+++ b/Userland/Libraries/LibJS/Runtime/StringPrototype.cpp
@@ -1085,13 +1085,16 @@ JS_DEFINE_NATIVE_FUNCTION(StringPrototype::search)
         if (vm.exception())
             return {};
     }
-    auto s = this_object.to_string(global_object);
+
+    auto string = this_object.to_utf16_string(global_object);
     if (vm.exception())
         return {};
+    Utf16View utf16_string_view { string };
+
     auto rx = regexp_create(global_object, regexp, js_undefined());
     if (!rx)
         return {};
-    return rx->invoke(*vm.well_known_symbol_search(), js_string(vm, s));
+    return rx->invoke(*vm.well_known_symbol_search(), js_string(vm, utf16_string_view));
 }
 
 // B.2.3.2.1 CreateHTML ( string, tag, attribute, value ), https://tc39.es/ecma262/#sec-createhtml
diff --git a/Userland/Libraries/LibJS/Tests/builtins/String/String.prototype.search.js b/Userland/Libraries/LibJS/Tests/builtins/String/String.prototype.search.js
index 07480adb9c..e104a521e5 100644
--- a/Userland/Libraries/LibJS/Tests/builtins/String/String.prototype.search.js
+++ b/Userland/Libraries/LibJS/Tests/builtins/String/String.prototype.search.js
@@ -46,10 +46,15 @@ test("override exec with non-function", () => {
     expect("test".search(re)).toBe(0);
 });
 
-// FIXME: RegExp.prototype [ @@search ] needs to support UTF-16.
-// test("UTF-16", () => {
-//     var s = "😀";
-//     expect(s.search("😀")).toBe(0);
-//     expect(s.search("\ud83d")).toBe(0);
-//     expect(s.search("\ude00")).toBe(1);
-// });
+test("UTF-16", () => {
+    var s = "😀";
+    expect(s.search("😀")).toBe(0);
+    expect(s.search("\ud83d")).toBe(0);
+    expect(s.search("\ude00")).toBe(1);
+    expect(s.search("foo")).toBe(-1);
+
+    s = "\u{80}\u{160}";
+    expect(s.search("\u{80}")).toBe(0);
+    expect(s.search("\u{160}")).toBe(1);
+    expect(s.search("foo")).toBe(-1);
+});