LibJS: Add %TypedArray%.prototype.keys

3 files changed, 58 insertions, 0 deletions

diff --git a/Userland/Libraries/LibJS/Runtime/TypedArrayPrototype.cpp b/Userland/Libraries/LibJS/Runtime/TypedArrayPrototype.cpp
index 6819c7367a..0ce14a7da5 100644
--- a/Userland/Libraries/LibJS/Runtime/TypedArrayPrototype.cpp
+++ b/Userland/Libraries/LibJS/Runtime/TypedArrayPrototype.cpp
@@ -5,6 +5,7 @@
  * SPDX-License-Identifier: BSD-2-Clause
  */
 
+#include <LibJS/Runtime/ArrayIterator.h>
 #include <LibJS/Runtime/GlobalObject.h>
 #include <LibJS/Runtime/TypedArray.h>
 #include <LibJS/Runtime/TypedArrayPrototype.h>
@@ -33,6 +34,7 @@ void TypedArrayPrototype::initialize(GlobalObject& object)
     define_native_function(vm.names.forEach, for_each, 1, attr);
     define_native_function(vm.names.some, some, 1, attr);
     define_native_function(vm.names.join, join, 1, attr);
+    define_native_function(vm.names.keys, keys, 0, attr);
 
     define_native_accessor(*vm.well_known_symbol_to_string_tag(), to_string_tag_getter, nullptr, Attribute::Configurable);
 
@@ -238,6 +240,15 @@ JS_DEFINE_NATIVE_FUNCTION(TypedArrayPrototype::join)
     return js_string(vm, builder.to_string());
 }
 
+// 23.2.3.16 %TypedArray%.prototype.keys ( ), https://tc39.es/ecma262/#sec-%typedarray%.prototype.keys
+JS_DEFINE_NATIVE_FUNCTION(TypedArrayPrototype::keys)
+{
+    auto typed_array = typed_array_from(vm, global_object);
+    if (!typed_array)
+        return {};
+    return ArrayIterator::create(global_object, typed_array, Object::PropertyKind::Key);
+}
+
 // 23.2.3.1 get %TypedArray%.prototype.buffer, https://tc39.es/ecma262/#sec-get-%typedarray%.prototype.buffer
 JS_DEFINE_NATIVE_GETTER(TypedArrayPrototype::buffer_getter)
 {
diff --git a/Userland/Libraries/LibJS/Runtime/TypedArrayPrototype.h b/Userland/Libraries/LibJS/Runtime/TypedArrayPrototype.h
index 72d58b79a3..fc9b1735fe 100644
--- a/Userland/Libraries/LibJS/Runtime/TypedArrayPrototype.h
+++ b/Userland/Libraries/LibJS/Runtime/TypedArrayPrototype.h
@@ -32,6 +32,7 @@ private:
     JS_DECLARE_NATIVE_FUNCTION(for_each);
     JS_DECLARE_NATIVE_FUNCTION(some);
     JS_DECLARE_NATIVE_FUNCTION(join);
+    JS_DECLARE_NATIVE_FUNCTION(keys);
 };
 
 }
diff --git a/Userland/Libraries/LibJS/Tests/builtins/TypedArray/TypedArray.prototype.keys.js b/Userland/Libraries/LibJS/Tests/builtins/TypedArray/TypedArray.prototype.keys.js
new file mode 100644
index 0000000000..7124ed36c5
--- /dev/null
+++ b/Userland/Libraries/LibJS/Tests/builtins/TypedArray/TypedArray.prototype.keys.js
@@ -0,0 +1,46 @@
+const TYPED_ARRAYS = [
+    Uint8Array,
+    Uint16Array,
+    Uint32Array,
+    Int8Array,
+    Int16Array,
+    Int32Array,
+    Float32Array,
+    Float64Array,
+];
+
+const BIGINT_TYPED_ARRAYS = [BigUint64Array, BigInt64Array];
+
+test("length is 0", () => {
+    TYPED_ARRAYS.forEach(T => {
+        expect(T.prototype.keys).toHaveLength(0);
+    });
+
+    BIGINT_TYPED_ARRAYS.forEach(T => {
+        expect(T.prototype.keys).toHaveLength(0);
+    });
+});
+
+test("basic functionality", () => {
+    TYPED_ARRAYS.forEach(T => {
+        const a = new T([30, 40, 50]);
+        const it = a.keys();
+        expect(it.next()).toEqual({ value: 0, done: false });
+        expect(it.next()).toEqual({ value: 1, done: false });
+        expect(it.next()).toEqual({ value: 2, done: false });
+        expect(it.next()).toEqual({ value: undefined, done: true });
+        expect(it.next()).toEqual({ value: undefined, done: true });
+        expect(it.next()).toEqual({ value: undefined, done: true });
+    });
+
+    BIGINT_TYPED_ARRAYS.forEach(T => {
+        const a = new T([30n, 40n, 50n]);
+        const it = a.keys();
+        expect(it.next()).toEqual({ value: 0, done: false });
+        expect(it.next()).toEqual({ value: 1, done: false });
+        expect(it.next()).toEqual({ value: 2, done: false });
+        expect(it.next()).toEqual({ value: undefined, done: true });
+        expect(it.next()).toEqual({ value: undefined, done: true });
+        expect(it.next()).toEqual({ value: undefined, done: true });
+    });
+});