LibJS: Implement Intl.NumberFormat.prototype.formatToParts

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

@@ -5,6 +5,7 @@
  */
 
 #include <AK/Array.h>
+#include <LibJS/Runtime/Array.h>
 #include <LibJS/Runtime/GlobalObject.h>
 #include <LibJS/Runtime/Intl/NumberFormat.h>
 #include <LibJS/Runtime/Intl/NumberFormatFunction.h>
@@ -959,6 +960,43 @@ String format_numeric(NumberFormat& number_format, double number)
     return result.build();
 }
 
+// 15.1.9 FormatNumericToParts ( numberFormat, x ), https://tc39.es/ecma402/#sec-formatnumbertoparts
+Array* format_numeric_to_parts(GlobalObject& global_object, NumberFormat& number_format, double number)
+{
+    auto& vm = global_object.vm();
+
+    // 1. Let parts be ? PartitionNumberPattern(numberFormat, x).
+    // Note: Our implementation of PartitionNumberPattern does not throw.
+    auto parts = partition_number_pattern(number_format, number);
+
+    // 2. Let result be ArrayCreate(0).
+    auto* result = MUST(Array::create(global_object, 0));
+
+    // 3. Let n be 0.
+    size_t n = 0;
+
+    // 4. For each Record { [[Type]], [[Value]] } part in parts, do
+    for (auto& part : parts) {
+        // a. Let O be OrdinaryObjectCreate(%Object.prototype%).
+        auto* object = Object::create(global_object, global_object.object_prototype());
+
+        // b. Perform ! CreateDataPropertyOrThrow(O, "type", part.[[Type]]).
+        MUST(object->create_data_property_or_throw(vm.names.type, js_string(vm, part.type)));
+
+        // c. Perform ! CreateDataPropertyOrThrow(O, "value", part.[[Value]]).
+        MUST(object->create_data_property_or_throw(vm.names.value, js_string(vm, move(part.value))));
+
+        // d. Perform ! CreateDataPropertyOrThrow(result, ! ToString(n), O).
+        MUST(result->create_data_property_or_throw(n, object));
+
+        // e. Increment n by 1.
+        ++n;
+    }
+
+    // 5. Return result.
+    return result;
+}
+
 static String cut_trailing_zeroes(StringView string, int cut)
 {
     // These steps are exactly the same between ToRawPrecision and ToRawFixed.