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LibJS: Rewrite Array.prototype.slice to be spec compliant

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This makes it generic in the process (which is required by jQuery)
This fixes 19 test262 test cases :^)
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Luke 2021-06-13 15:49:52 +01:00 • committed by Linus Groh
parent 2e1a01a499
commit d72aeb2e1a
3 changed files with 87 additions and 28 deletions
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88
Userland/Libraries/LibJS/Runtime/ArrayPrototype.cpp
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@ -387,46 +387,78 @@ JS_DEFINE_NATIVE_FUNCTION(ArrayPrototype::concat)
// 23.1.3.25 Array.prototype.slice ( start, end ), https://tc39.es/ecma262/#sec-array.prototype.slice
JS_DEFINE_NATIVE_FUNCTION(ArrayPrototype::slice)
{
auto* array = Array::typed_this(vm, global_object);
if (!array)
auto* this_object = vm.this_value(global_object).to_object(global_object);
if (!this_object)
return {};
auto* new_array = Array::create(global_object);
if (vm.argument_count() == 0) {
new_array->indexed_properties().append_all(array, array->indexed_properties());
if (vm.exception())
return {};
return new_array;
}
ssize_t array_size = static_cast<ssize_t>(array->indexed_properties().array_like_size());
auto start_slice = vm.argument(0).to_i32(global_object);
auto initial_length = length_of_array_like(global_object, *this_object);
if (vm.exception())
return {};
auto end_slice = array_size;
if (start_slice > array_size)
return new_array;
auto relative_start = vm.argument(0).to_integer_or_infinity(global_object);
if (vm.exception())
return {};
if (start_slice < 0)
start_slice = end_slice + start_slice;
double actual_start;
if (vm.argument_count() >= 2) {
end_slice = vm.argument(1).to_i32(global_object);
if (vm.exception())
return {};
if (end_slice < 0)
end_slice = array_size + end_slice;
else if (end_slice > array_size)
end_slice = array_size;
}
if (Value(relative_start).is_negative_infinity())
actual_start = 0.0;
else if (relative_start < 0.0)
actual_start = max((double)initial_length + relative_start, 0.0);
else
actual_start = min(relative_start, (double)initial_length);
for (ssize_t i = start_slice; i < end_slice; ++i) {
new_array->indexed_properties().append(array->get(i));
double relative_end;
if (vm.argument(1).is_undefined() || vm.argument(1).is_empty()) {
relative_end = (double)initial_length;
} else {
relative_end = vm.argument(1).to_integer_or_infinity(global_object);
if (vm.exception())
return {};
}
double final;
if (Value(relative_end).is_negative_infinity())
final = 0.0;
else if (relative_end < 0.0)
final = max((double)initial_length + relative_end, 0.0);
else
final = min(relative_end, (double)initial_length);
auto count = max(final - actual_start, 0.0);
// FIXME: Use ArraySpeciesCreate.
auto* new_array = Array::create(global_object, (size_t)count);
if (vm.exception())
return {};
size_t index = 0;
while (actual_start < final) {
bool present = this_object->has_property(actual_start);
if (vm.exception())
return {};
if (present) {
auto value = this_object->get(actual_start).value_or(js_undefined());
if (vm.exception())
return {};
new_array->define_property(index, value);
if (vm.exception())
return {};
}
++actual_start;
++index;
}
new_array->put(vm.names.length, Value(index));
if (vm.exception())
return {};
return new_array;
}