LibJS: Convert DisplayNames AOs to ThrowCompletionOr

Userland/Libraries/LibJS/Runtime/Intl/DisplayNames.cpp

@@ -99,69 +99,59 @@ StringView DisplayNames::fallback_string() const
 }
 
 // 12.1.1 CanonicalCodeForDisplayNames ( type, code ), https://tc39.es/ecma402/#sec-canonicalcodefordisplaynames
-Value canonical_code_for_display_names(GlobalObject& global_object, DisplayNames::Type type, StringView code)
+ThrowCompletionOr<Value> canonical_code_for_display_names(GlobalObject& global_object, DisplayNames::Type type, StringView code)
 {
     auto& vm = global_object.vm();
 
     // 1. If type is "language", then
     if (type == DisplayNames::Type::Language) {
         // a. If code does not match the unicode_language_id production, throw a RangeError exception.
-        if (!Unicode::parse_unicode_language_id(code).has_value()) {
-            vm.throw_exception<RangeError>(global_object, ErrorType::OptionIsNotValidValue, code, "language"sv);
-            return {};
-        }
+        if (!Unicode::parse_unicode_language_id(code).has_value())
+            return vm.throw_completion<RangeError>(global_object, ErrorType::OptionIsNotValidValue, code, "language"sv);
 
         // b. If IsStructurallyValidLanguageTag(code) is false, throw a RangeError exception.
         auto locale_id = is_structurally_valid_language_tag(code);
-        if (!locale_id.has_value()) {
-            vm.throw_exception<RangeError>(global_object, ErrorType::IntlInvalidLanguageTag, code);
-            return {};
-        }
+        if (!locale_id.has_value())
+            return vm.throw_completion<RangeError>(global_object, ErrorType::IntlInvalidLanguageTag, code);
 
         // c. Set code to CanonicalizeUnicodeLocaleId(code).
         // d. Return code.
         auto canonicalized_tag = JS::Intl::canonicalize_unicode_locale_id(*locale_id);
-        return js_string(vm, move(canonicalized_tag));
+        return { js_string(vm, move(canonicalized_tag)) };
     }
 
     // 2. If type is "region", then
     if (type == DisplayNames::Type::Region) {
         // a. If code does not match the unicode_region_subtag production, throw a RangeError exception.
-        if (!Unicode::is_unicode_region_subtag(code)) {
-            vm.throw_exception<RangeError>(global_object, ErrorType::OptionIsNotValidValue, code, "region"sv);
-            return {};
-        }
+        if (!Unicode::is_unicode_region_subtag(code))
+            return vm.throw_completion<RangeError>(global_object, ErrorType::OptionIsNotValidValue, code, "region"sv);
 
         // b. Let code be the result of mapping code to upper case as described in 6.1.
         // c. Return code.
-        return js_string(vm, code.to_uppercase_string());
+        return { js_string(vm, code.to_uppercase_string()) };
     }
 
     // 3. If type is "script", then
     if (type == DisplayNames::Type::Script) {
         // a. If code does not match the unicode_script_subtag production, throw a RangeError exception.
-        if (!Unicode::is_unicode_script_subtag(code)) {
-            vm.throw_exception<RangeError>(global_object, ErrorType::OptionIsNotValidValue, code, "script"sv);
-            return {};
-        }
+        if (!Unicode::is_unicode_script_subtag(code))
+            return vm.throw_completion<RangeError>(global_object, ErrorType::OptionIsNotValidValue, code, "script"sv);
 
         // b. Let code be the result of mapping the first character in code to upper case, and mapping the second, third, and fourth character in code to lower case, as described in 6.1.
         // c. Return code.
-        return js_string(vm, code.to_titlecase_string());
+        return { js_string(vm, code.to_titlecase_string()) };
     }
 
     // 4. Assert: type is "currency".
     VERIFY(type == DisplayNames::Type::Currency);
 
     // 5. If ! IsWellFormedCurrencyCode(code) is false, throw a RangeError exception.
-    if (!is_well_formed_currency_code(code)) {
-        vm.throw_exception<RangeError>(global_object, ErrorType::OptionIsNotValidValue, code, "currency"sv);
-        return {};
-    }
+    if (!is_well_formed_currency_code(code))
+        return vm.throw_completion<RangeError>(global_object, ErrorType::OptionIsNotValidValue, code, "currency"sv);
 
     // 6. Let code be the result of mapping code to upper case as described in 6.1.
     // 7. Return code.
-    return js_string(vm, code.to_uppercase_string());
+    return { js_string(vm, code.to_uppercase_string()) };
 }
 
 }

Userland/Libraries/LibJS/Runtime/Intl/DisplayNames.h

@@ -62,6 +62,6 @@ private:
     Fallback m_fallback { Fallback::Invalid }; // [[Fallback]]
 };
 
-Value canonical_code_for_display_names(GlobalObject& global_object, DisplayNames::Type type, StringView code);
+ThrowCompletionOr<Value> canonical_code_for_display_names(GlobalObject& global_object, DisplayNames::Type type, StringView code);
 
 }

Userland/Libraries/LibJS/Runtime/Intl/DisplayNamesPrototype.cpp

@@ -50,9 +50,7 @@ JS_DEFINE_NATIVE_FUNCTION(DisplayNamesPrototype::of)
     code = js_string(vm, move(code_string));
 
     // 4. Let code be ? CanonicalCodeForDisplayNames(displayNames.[[Type]], code).
-    code = canonical_code_for_display_names(global_object, display_names->type(), code.as_string().string());
-    if (vm.exception())
-        return {};
+    code = TRY_OR_DISCARD(canonical_code_for_display_names(global_object, display_names->type(), code.as_string().string()));
 
     // 5. Let fields be displayNames.[[Fields]].
     // 6. If fields has a field [[<code>]], return fields.[[<code>]].