LibJS: Implement Intl %SegmentsPrototype%[@@iterator]

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

@@ -5,6 +5,7 @@
  */
 
 #include <LibJS/Runtime/GlobalObject.h>
+#include <LibJS/Runtime/Intl/SegmentIterator.h>
 #include <LibJS/Runtime/Intl/Segments.h>
 #include <LibJS/Runtime/Intl/SegmentsPrototype.h>
 
@@ -19,6 +20,28 @@ SegmentsPrototype::SegmentsPrototype(GlobalObject& global_object)
 void SegmentsPrototype::initialize(GlobalObject& global_object)
 {
     Object::initialize(global_object);
+
+    auto& vm = this->vm();
+
+    u8 attr = Attribute::Writable | Attribute::Configurable;
+    define_native_function(*vm.well_known_symbol_iterator(), symbol_iterator, 0, attr);
+}
+
+// 18.5.2.2 %SegmentsPrototype% [ @@iterator ] ( ), https://tc39.es/ecma402/#sec-%segmentsprototype%-@@iterator
+JS_DEFINE_NATIVE_FUNCTION(SegmentsPrototype::symbol_iterator)
+{
+    // 1. Let segments be the this value.
+    // 2. Perform ? RequireInternalSlot(segments, [[SegmentsSegmenter]]).
+    auto* segments = TRY(typed_this_object(global_object));
+
+    // 3. Let segmenter be segments.[[SegmentsSegmenter]].
+    auto& segmenter = segments->segments_segmenter();
+
+    // 4. Let string be segments.[[SegmentsString]].
+    auto& string = segments->segments_string();
+
+    // 5. Return ! CreateSegmentIterator(segmenter, string).
+    return SegmentIterator::create(global_object, segmenter, string);
 }
 
 }

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

@@ -18,6 +18,9 @@ public:
     explicit SegmentsPrototype(GlobalObject&);
     virtual void initialize(GlobalObject&) override;
     virtual ~SegmentsPrototype() override = default;
+
+private:
+    JS_DECLARE_NATIVE_FUNCTION(symbol_iterator);
 };
 
 }

Userland/Libraries/LibJS/Tests/builtins/Intl/Segmenter/Segmenter.prototype.segment.js

@@ -9,4 +9,12 @@ describe("correct behavior", () => {
             Object.getPrototypeOf(segmenter.segment("friends"))
         );
     });
+
+    test("returns segments object segment iterator", () => {
+        const segmenter = new Intl.Segmenter();
+        const segments = segmenter.segment("hello friends!");
+        expect(Object.getPrototypeOf(segments[Symbol.iterator]())[Symbol.toStringTag]).toBe(
+            "Segmenter String Iterator"
+        );
+    });
 });