LibJS: Convert to_length() to ThrowCompletionOr

Author: https://github.com/IdanHo
Commit: aad12b050b
Pull-request: https://github.com/SerenityOS/serenity/pull/10522
Reviewed-by: https://github.com/linusg ✅

Userland/Applications/Spreadsheet/JSIntegration.cpp

@@ -425,9 +425,7 @@ JS_DEFINE_NATIVE_FUNCTION(WorkbookObject::sheet)
                 return JS::Value(&sheet.global_object());
         }
     } else {
-        auto index = name_value.to_length(global_object);
-        if (vm.exception())
-            return {};
+        auto index = TRY_OR_DISCARD(name_value.to_length(global_object));
         if (index < workbook.sheets().size())
             return JS::Value(&workbook.sheets()[index].global_object());
     }

Userland/Libraries/LibJS/Runtime/AbstractOperations.cpp

@@ -79,10 +79,7 @@ ThrowCompletionOr<size_t> length_of_array_like(GlobalObject& global_object, Obje
 {
     auto& vm = global_object.vm();
     auto result = TRY(object.get(vm.names.length));
-    auto length = result.to_length(global_object);
-    if (auto* exception = vm.exception())
-        return throw_completion(exception->value());
-    return length;
+    return result.to_length(global_object);
 }
 
 // 7.3.19 CreateListFromArrayLike ( obj [ , elementTypes ] ), https://tc39.es/ecma262/#sec-createlistfromarraylike

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

@@ -212,9 +212,8 @@ ThrowCompletionOr<Vector<String>> canonicalize_locale_list(GlobalObject& global_
     }
 
     // 5. Let len be ? ToLength(? Get(O, "length")).
-    auto length = TRY(object->get(vm.names.length)).to_length(global_object);
-    if (auto* exception = vm.exception())
-        return throw_completion(exception->value());
+    auto length_value = TRY(object->get(vm.names.length));
+    auto length = TRY(length_value.to_length(global_object));
 
     // 6. Let k be 0.
     // 7. Repeat, while k < len,

Userland/Libraries/LibJS/Runtime/RegExpPrototype.cpp

@@ -72,9 +72,8 @@ static ThrowCompletionOr<void> increment_last_index(GlobalObject& global_object,
 {
     auto& vm = global_object.vm();
 
-    auto last_index = TRY(regexp_object.get(vm.names.lastIndex)).to_length(global_object);
-    if (auto* exception = vm.exception())
-        return throw_completion(exception->value());
+    auto last_index_value = TRY(regexp_object.get(vm.names.lastIndex));
+    auto last_index = TRY(last_index_value.to_length(global_object));
 
     last_index = advance_string_index(string, last_index, unicode);
     TRY(regexp_object.set(vm.names.lastIndex, Value(last_index), Object::ShouldThrowExceptions::Yes));
@@ -154,9 +153,8 @@ static Value regexp_builtin_exec(GlobalObject& global_object, RegExpObject& rege
     // FIXME: This should try using internal slots [[RegExpMatcher]], [[OriginalFlags]], etc.
     auto& vm = global_object.vm();
 
-    auto last_index = TRY_OR_DISCARD(regexp_object.get(vm.names.lastIndex)).to_length(global_object);
-    if (vm.exception())
-        return {};
+    auto last_index_value = TRY_OR_DISCARD(regexp_object.get(vm.names.lastIndex));
+    auto last_index = TRY_OR_DISCARD(last_index_value.to_length(global_object));
 
     auto& regex = regexp_object.regex();
     bool global = regex.options().has_flag_set(ECMAScriptFlags::Global);
@@ -457,9 +455,8 @@ JS_DEFINE_NATIVE_FUNCTION(RegExpPrototype::symbol_match_all)
     if (vm.exception())
         return {};
     auto* matcher = TRY_OR_DISCARD(matcher_value.to_object(global_object));
-    auto last_index = TRY_OR_DISCARD(regexp_object->get(vm.names.lastIndex)).to_length(global_object);
-    if (vm.exception())
-        return {};
+    auto last_index_value = TRY_OR_DISCARD(regexp_object->get(vm.names.lastIndex));
+    auto last_index = TRY_OR_DISCARD(last_index_value.to_length(global_object));
 
     TRY_OR_DISCARD(matcher->set(vm.names.lastIndex, Value(last_index), Object::ShouldThrowExceptions::Yes));
 
@@ -668,9 +665,8 @@ JS_DEFINE_NATIVE_FUNCTION(RegExpPrototype::symbol_split)
             continue;
         }
 
-        auto last_index = TRY_OR_DISCARD(splitter->get(vm.names.lastIndex)).to_length(global_object); // 'e' in the spec.
-        if (vm.exception())
-            return {};
+        auto last_index_value = TRY_OR_DISCARD(splitter->get(vm.names.lastIndex));
+        auto last_index = TRY_OR_DISCARD(last_index_value.to_length(global_object)); // 'e' in the spec.
         last_index = min(last_index, string_view.length_in_code_units());
 
         if (last_index == last_match_end) {

Userland/Libraries/LibJS/Runtime/RegExpStringIteratorPrototype.cpp

@@ -58,9 +58,8 @@ JS_DEFINE_NATIVE_FUNCTION(RegExpStringIteratorPrototype::next)
     auto match_string_value = TRY_OR_DISCARD(match_object->get(0));
     auto match_string = TRY_OR_DISCARD(match_string_value.to_string(global_object));
     if (match_string.is_empty()) {
-        auto last_index = TRY_OR_DISCARD(iterator->regexp_object().get(vm.names.lastIndex)).to_length(global_object);
-        if (vm.exception())
-            return {};
+        auto last_index_value = TRY_OR_DISCARD(iterator->regexp_object().get(vm.names.lastIndex));
+        auto last_index = TRY_OR_DISCARD(last_index_value.to_length(global_object));
 
         last_index = advance_string_index(iterator->string().view(), last_index, iterator->unicode());
 

Userland/Libraries/LibJS/Runtime/StringPrototype.cpp

@@ -468,9 +468,7 @@ static Value pad_string(GlobalObject& global_object, Utf16String string, PadPlac
     auto& vm = global_object.vm();
     auto string_length = string.length_in_code_units();
 
-    auto max_length = vm.argument(0).to_length(global_object);
-    if (vm.exception())
-        return {};
+    auto max_length = TRY_OR_DISCARD(vm.argument(0).to_length(global_object));
     if (max_length <= string_length)
         return js_string(vm, move(string));
 

Userland/Libraries/LibJS/Runtime/Value.cpp

@@ -692,13 +692,13 @@ ThrowCompletionOr<u8> Value::to_u8_clamp(GlobalObject& global_object) const
 }
 
 // 7.1.20 ToLength ( argument ), https://tc39.es/ecma262/#sec-tolength
-size_t Value::to_length(GlobalObject& global_object) const
+ThrowCompletionOr<size_t> Value::to_length(GlobalObject& global_object) const
 {
     auto& vm = global_object.vm();
 
     auto len = to_integer_or_infinity(global_object);
-    if (vm.exception())
-        return {};
+    if (auto* exception = vm.exception())
+        return throw_completion(exception->value());
     if (len <= 0)
         return 0;
     // FIXME: The spec says that this function's output range is 0 - 2^53-1. But we don't want to overflow the size_t.
@@ -720,8 +720,7 @@ size_t Value::to_index(GlobalObject& global_object) const
         vm.throw_exception<RangeError>(global_object, ErrorType::InvalidIndex);
         return {};
     }
-    auto index = Value(integer_index).to_length(global_object);
-    VERIFY(!vm.exception());
+    auto index = MUST(Value(integer_index).to_length(global_object));
     if (integer_index != index) {
         vm.throw_exception<RangeError>(global_object, ErrorType::InvalidIndex);
         return {};

Userland/Libraries/LibJS/Runtime/Value.h

@@ -322,7 +322,7 @@ public:
     ThrowCompletionOr<i8> to_i8(GlobalObject&) const;
     ThrowCompletionOr<u8> to_u8(GlobalObject&) const;
     ThrowCompletionOr<u8> to_u8_clamp(GlobalObject&) const;
-    size_t to_length(GlobalObject&) const;
+    ThrowCompletionOr<size_t> to_length(GlobalObject&) const;
     size_t to_index(GlobalObject&) const;
     double to_integer_or_infinity(GlobalObject&) const;
     bool to_boolean() const;