Added Array.prototype.findIndex
@@ -435,6 +435,43 @@ pub fn find(this: &Value, args: &[Value], interpreter: &mut Interpreter) -> Resu
Ok(Gc::new(ValueData::Undefined))
}
+/// Array.prototype.findIndex ( predicate [ , thisArg ] )
+///
+/// This method executes the provided predicate function for each element of the array.
+/// If the predicate function returns `true` for an element, this method returns the index of the element.
+/// If all elements return `false`, the value `-1` is returned.
+/// <https://tc39.es/ecma262/#sec-array.prototype.findindex/>
+pub fn find_index(this: &Value, args: &[Value], interpreter: &mut Interpreter) -> ResultValue {
+ if args.is_empty() {
+ return Err(to_value(
+ "Missing argument for Array.prototype.findIndex".to_string(),
+ ));
+ }
+
+ let predicate_arg = args.get(0).expect("Could not get `predicate` argument.");
+
+ let this_arg = args
+ .get(1)
+ .cloned()
+ .unwrap_or_else(|| Gc::new(ValueData::Undefined));
+
+ let length: i32 =
+ from_value(this.get_field_slice("length")).expect("Could not get `length` property.");
+
+ for i in 0..length {
+ let element = this.get_field(&i.to_string());
+ let arguments = vec![element.clone(), to_value(i), this.clone()];
+
+ let result = interpreter.call(predicate_arg, &this_arg, arguments)?;
+
+ if result.is_true() {
+ return Ok(Gc::new(ValueData::Number(f64::from(i))));
+ }
+ }
+
+ Ok(Gc::new(ValueData::Number(f64::from(-1))))
+}
+
/// Create a new `Array` object
pub fn create_constructor(global: &Value) -> Value {
// Create Constructor
@@ -468,6 +505,7 @@ pub fn create_constructor(global: &Value) -> Value {
array_prototype.set_field_slice("unshift", to_value(unshift as NativeFunctionData));
array_prototype.set_field_slice("every", to_value(every as NativeFunctionData));
array_prototype.set_field_slice("find", to_value(find as NativeFunctionData));
+ array_prototype.set_field_slice("findIndex", to_value(find_index as NativeFunctionData));
array_prototype.set_field_slice("indexOf", index_of_func);
array_prototype.set_field_slice("lastIndexOf", last_index_of_func);
@@ -589,6 +627,32 @@ mod tests {
assert_eq!(found, String::from("a"));
}
+ #[test]
+ fn find_index() {
+ let realm = Realm::create();
+ let mut engine = Executor::new(realm);
+
+ let code = r#"
+ function comp(item) {
+ return item == 2;
+ }
+ let many = [1, 2, 3];
+ let empty = [];
+ let missing = [4, 5, 6];
+ "#;
+
+ forward(&mut engine, code);
+
+ let many = forward(&mut engine, "many.findIndex(comp)");
+ assert_eq!(many, String::from("1"));
+
+ let empty = forward(&mut engine, "empty.findIndex(comp)");
+ assert_eq!(empty, String::from("-1"));
+
+ let missing = forward(&mut engine, "missing.findIndex(comp)");
+ assert_eq!(missing, String::from("-1"));
+ }
+
#[test]
fn index_of() {
let realm = Realm::create();
