From 27fc3cfe75df511eb657dbe6304683ef0bb4ec86 Mon Sep 17 00:00:00 2001
From: Timothy Flynn <trflynn89@pm.me>
Date: Wed, 1 Sep 2021 22:26:06 -0400
Subject: [PATCH] LibJS: Handle existing Intl.Locale objects in
 CanonicalizeLocaleList

---
 .../LibJS/Runtime/Intl/AbstractOperations.cpp | 22 ++++++++++++-------
 .../builtins/Intl/Intl.getCanonicalLocales.js |  8 +++++++
 2 files changed, 22 insertions(+), 8 deletions(-)

diff --git a/Userland/Libraries/LibJS/Runtime/Intl/AbstractOperations.cpp b/Userland/Libraries/LibJS/Runtime/Intl/AbstractOperations.cpp
index 34aa2869f6..36283eb16c 100644
--- a/Userland/Libraries/LibJS/Runtime/Intl/AbstractOperations.cpp
+++ b/Userland/Libraries/LibJS/Runtime/Intl/AbstractOperations.cpp
@@ -12,6 +12,7 @@
 #include <LibJS/Runtime/Array.h>
 #include <LibJS/Runtime/GlobalObject.h>
 #include <LibJS/Runtime/Intl/AbstractOperations.h>
+#include <LibJS/Runtime/Intl/Locale.h>
 #include <LibUnicode/Locale.h>
 
 namespace JS::Intl {
@@ -150,8 +151,7 @@ Vector<String> canonicalize_locale_list(GlobalObject& global_object, Value local
 
     Object* object = nullptr;
     // 3. If Type(locales) is String or Type(locales) is Object and locales has an [[InitializedLocale]] internal slot, then
-    // FIXME: When we have an Intl.Locale object, handle it it here.
-    if (locales.is_string()) {
+    if (locales.is_string() || (locales.is_object() && is<Locale>(locales.as_object()))) {
         // a. Let O be CreateArrayFromList(« locales »).
         object = Array::create_from(global_object, { locales });
     }
@@ -195,14 +195,20 @@ Vector<String> canonicalize_locale_list(GlobalObject& global_object, Value local
                 return {};
             }
 
+            String tag;
+
             // iii. If Type(kValue) is Object and kValue has an [[InitializedLocale]] internal slot, then
-            //     1. Let tag be kValue.[[Locale]].
+            if (key_value.is_object() && is<Locale>(key_value.as_object())) {
+                // 1. Let tag be kValue.[[Locale]].
+                tag = static_cast<Locale const&>(key_value.as_object()).locale();
+            }
             // iv. Else,
-            //     1. Let tag be ? ToString(kValue).
-            // FIXME: When we have an Intl.Locale object, handle it it here.
-            auto tag = key_value.to_string(global_object);
-            if (vm.exception())
-                return {};
+            else {
+                // 1. Let tag be ? ToString(kValue).
+                tag = key_value.to_string(global_object);
+                if (vm.exception())
+                    return {};
+            }
 
             // v. If IsStructurallyValidLanguageTag(tag) is false, throw a RangeError exception.
             auto locale_id = is_structurally_valid_language_tag(tag);
diff --git a/Userland/Libraries/LibJS/Tests/builtins/Intl/Intl.getCanonicalLocales.js b/Userland/Libraries/LibJS/Tests/builtins/Intl/Intl.getCanonicalLocales.js
index 4164897e23..bda470aa46 100644
--- a/Userland/Libraries/LibJS/Tests/builtins/Intl/Intl.getCanonicalLocales.js
+++ b/Userland/Libraries/LibJS/Tests/builtins/Intl/Intl.getCanonicalLocales.js
@@ -115,4 +115,12 @@ describe("normal behavior", () => {
             "en-US-u-1k-aaa-2k-ccc",
         ]);
     });
+
+    test("canonicalize locale objects", () => {
+        const en = new Intl.Locale("en", { script: "Latn" });
+        expect(Intl.getCanonicalLocales(en)).toEqual(["en-Latn"]);
+
+        const es = new Intl.Locale("es", { region: "419" });
+        expect(Intl.getCanonicalLocales([en, es])).toEqual(["en-Latn", "es-419"]);
+    });
 });