LibJS: Fix small issues in Array.prototype.concat

cubiclove · Jun 22, 2021 · 9d1fd40 · 9d1fd40
1 parent 91de113
commit 9d1fd40
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Showing 2 changed files with 12 additions and 2 deletions.
diff --git a/Userland/Libraries/LibJS/Runtime/ArrayPrototype.cpp b/Userland/Libraries/LibJS/Runtime/ArrayPrototype.cpp
@@ -531,7 +531,7 @@ JS_DEFINE_NATIVE_FUNCTION(ArrayPrototype::concat)
  if (!spreadable.is_undefined())
  return spreadable.to_boolean();
 
- return object->is_array();
+ return val.is_array(global_object);
  };
 
  auto append_to_new_array = [&vm, &is_concat_spreadable, &new_array, &global_object, &n](Value arg) {
@@ -546,7 +546,7 @@ JS_DEFINE_NATIVE_FUNCTION(ArrayPrototype::concat)
  if (vm.exception())
  return;
 
- if (length + k > MAX_ARRAY_LIKE_INDEX) {
+ if (n + length > MAX_ARRAY_LIKE_INDEX) {
  vm.throw_exception<TypeError>(global_object, ErrorType::ArrayMaxSize);
  return;
  }

diff --git a/Userland/Libraries/LibJS/Tests/builtins/Array/Array.prototype.concat.js b/Userland/Libraries/LibJS/Tests/builtins/Array/Array.prototype.concat.js
@@ -40,4 +40,14 @@ describe("normal behavior", () => {
  expect(concatenated[4]).toBe(1);
  expect(concatenated[5]).toEqual([2, 3]);
  });
+
+ test("Proxy is concatenated as array", () => {
+ var proxy = new Proxy([9, 8], {});
+ var concatenated = array.concat(proxy);
+ expect(array).toHaveLength(1);
+ expect(concatenated).toHaveLength(3);
+ expect(concatenated[0]).toBe("hello");
+ expect(concatenated[1]).toBe(9);
+ expect(concatenated[2]).toBe(8);
+ });
 });