Add Array.prototype.every method fixes #163

src/lib/js/array.rs

@@ -271,6 +271,41 @@ pub fn unshift(this: &Value, args: &[Value], _: &mut Interpreter) -> ResultValue
     Ok(to_value(temp))
 }
 
+/// Array.prototype.every ( callback, [ thisArg ] )
+///
+/// The every method executes the provided callback function once for each
+/// element present in the array until it finds the one where callback returns
+/// a falsy value. It returns `false` if it finds such element, otherwise it
+/// returns `true`.
+/// <https://tc39.es/ecma262/#sec-array.prototype.every/>
+pub fn every(this: &Value, args: &[Value], interpreter: &mut Interpreter) -> ResultValue {
+    if args.is_empty() {
+        return Err(to_value(
+            "missing callback when calling function Array.prototype.every".to_string(),
+        ));
+    }
+    let callback = &args[0];
+    let this_arg = if args.len() > 1 {
+        args[1].clone()
+    } else {
+        Gc::new(ValueData::Undefined)
+    };
+    let mut i = 0;
+    let max_len: i32 = from_value(this.get_field_slice("length")).unwrap();
+    let mut len = max_len;
+    while i < len {
+        let element = this.get_field(&i.to_string());
+        let arguments = vec![element.clone(), to_value(i), this.clone()];
+        let result = interpreter.call(callback, &this_arg, arguments)?.is_true();
+        if !result {
+            return Ok(to_value(false));
+        }
+        len = std::cmp::min(max_len, from_value(this.get_field_slice("length")).unwrap());
+        i += 1;
+    }
+    Ok(to_value(true))
+}
+
 /// Array.prototype.indexOf ( searchElement[, fromIndex ] )
 ///
 ///
@@ -431,6 +466,7 @@ pub fn create_constructor(global: &Value) -> Value {
     array_prototype.set_field_slice("reverse", to_value(reverse as NativeFunctionData));
     array_prototype.set_field_slice("shift", to_value(shift as NativeFunctionData));
     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("indexOf", index_of_func);
     array_prototype.set_field_slice("lastIndexOf", last_index_of_func);
@@ -493,6 +529,51 @@ mod tests {
         assert_eq!(many, String::from("a.b.c"));
     }
 
+    #[test]
+    fn every() {
+        let realm = Realm::create();
+        let mut engine = Executor::new(realm);
+        // taken from https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/every
+        let init = r#"
+        let empty = [];
+
+        let array = [11, 23, 45];
+        function callback(element) {
+            return element > 10;
+        }
+        function callback2(element) {
+            return element < 10;
+        }
+
+        let appendArray = [1,2,3,4];
+        function appendingCallback(elem,index,arr) {
+          arr.push('new');
+          return elem !== "new";
+        }
+
+        let delArray = [1,2,3,4];
+        function deletingCallback(elem,index,arr) {
+          arr.pop()
+          return elem < 3;
+        }
+        "#;
+        forward(&mut engine, init);
+        let result = forward(&mut engine, "array.every(callback);");
+        assert_eq!(result, "true");
+
+        let result = forward(&mut engine, "empty.every(callback);");
+        assert_eq!(result, "true");
+
+        let result = forward(&mut engine, "array.every(callback2);");
+        assert_eq!(result, "false");
+
+        let result = forward(&mut engine, "appendArray.every(appendingCallback);");
+        assert_eq!(result, "true");
+
+        let result = forward(&mut engine, "delArray.every(deletingCallback);");
+        assert_eq!(result, "true");
+    }
+
     #[test]
     fn find() {
         let realm = Realm::create();