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LibJS: Implement String.prototype.charCodeAt

It's broken for strings with characters outside 7-bit ASCII, but
it's broken in the same way as several existing functions (e.g.
charAt()), so that's probably ok for now.
This commit is contained in:
Nico Weber 2020-07-22 09:38:39 -04:00 committed by Andreas Kling
parent 7230b7aad7
commit 979e02c0a8
4 changed files with 40 additions and 0 deletions

View file

@ -72,6 +72,7 @@ void StringPrototype::initialize(Interpreter& interpreter, GlobalObject& global_
define_native_property("length", length_getter, nullptr, 0);
define_native_function("charAt", char_at, 1, attr);
define_native_function("charCodeAt", char_code_at, 1, attr);
define_native_function("repeat", repeat, 1, attr);
define_native_function("startsWith", starts_with, 1, attr);
define_native_function("indexOf", index_of, 1, attr);
@ -111,6 +112,22 @@ JS_DEFINE_NATIVE_FUNCTION(StringPrototype::char_at)
return js_string(interpreter, string.substring(index, 1));
}
JS_DEFINE_NATIVE_FUNCTION(StringPrototype::char_code_at)
{
auto string = ak_string_from(interpreter, global_object);
if (string.is_null())
return {};
i32 index = 0;
if (interpreter.argument_count()) {
index = interpreter.argument(0).to_i32(interpreter);
if (interpreter.exception())
return {};
}
if (index < 0 || index >= static_cast<i32>(string.length()))
return js_nan();
return Value((i32)string[index]);
}
JS_DEFINE_NATIVE_FUNCTION(StringPrototype::repeat)
{
auto string = ak_string_from(interpreter, global_object);

View file

@ -40,6 +40,7 @@ public:
private:
JS_DECLARE_NATIVE_FUNCTION(char_at);
JS_DECLARE_NATIVE_FUNCTION(char_code_at);
JS_DECLARE_NATIVE_FUNCTION(repeat);
JS_DECLARE_NATIVE_FUNCTION(starts_with);
JS_DECLARE_NATIVE_FUNCTION(index_of);

View file

@ -1,6 +1,7 @@
test("basic functionality", () => {
const genericStringPrototypeFunctions = [
"charAt",
"charCodeAt",
"repeat",
"startsWith",
"indexOf",

View file

@ -0,0 +1,21 @@
test("basic functionality", () => {
expect(String.prototype.charAt).toHaveLength(1);
var s = "Foobar";
expect(typeof s).toBe("string");
expect(s).toHaveLength(6);
expect(s.charCodeAt(0)).toBe(70);
expect(s.charCodeAt(1)).toBe(111);
expect(s.charCodeAt(2)).toBe(111);
expect(s.charCodeAt(3)).toBe(98);
expect(s.charCodeAt(4)).toBe(97);
expect(s.charCodeAt(5)).toBe(114);
expect(s.charCodeAt(6)).toBe(NaN);
expect(s.charCodeAt(-1)).toBe(NaN);
expect(s.charCodeAt()).toBe(70);
expect(s.charCodeAt(NaN)).toBe(70);
expect(s.charCodeAt("foo")).toBe(70);
expect(s.charCodeAt(undefined)).toBe(70);
});