Adding TryFromJs implementations for tuples (#3843)

* Adding TryFromJs implementations for tuples

* rustfmt and clippies

* rustfmt

* Remove unit type

* Clippies

core/engine/src/value/conversions/try_from_js.rs

@@ -5,6 +5,7 @@ use num_bigint::BigInt;
 use crate::{js_string, Context, JsBigInt, JsNativeError, JsObject, JsResult, JsString, JsValue};
 
 mod collections;
+mod tuples;
 
 /// This trait adds a fallible and efficient conversions from a [`JsValue`] to Rust types.
 pub trait TryFromJs: Sized {
@@ -367,6 +368,56 @@ fn value_into_vec() {
     ]);
 }
 
+#[test]
+fn value_into_tuple() {
+    use boa_engine::{run_test_actions, TestAction};
+    use indoc::indoc;
+
+    run_test_actions([
+        TestAction::assert_with_op(indoc! {r#" [42, "hello", true] "#}, |value, context| {
+            type TestType = (i32, String, bool);
+            TestType::try_from_js(&value, context).unwrap() == (42, "hello".to_string(), true)
+        }),
+        TestAction::assert_with_op(indoc! {r#" [42, "hello", true] "#}, |value, context| {
+            type TestType = (i32, String, Option<bool>, Option<u8>);
+            TestType::try_from_js(&value, context).unwrap()
+                == (42, "hello".to_string(), Some(true), None)
+        }),
+        TestAction::assert_with_op(indoc! {r#" [] "#}, |value, context| {
+            type TestType = (
+                Option<bool>,
+                Option<bool>,
+                Option<bool>,
+                Option<bool>,
+                Option<bool>,
+                Option<bool>,
+                Option<bool>,
+                Option<bool>,
+                Option<bool>,
+                Option<bool>,
+            );
+            TestType::try_from_js(&value, context).unwrap()
+                == (None, None, None, None, None, None, None, None, None, None)
+        }),
+        TestAction::assert_with_op(indoc!(r#"[42, "hello", {}]"#), |value, context| {
+            type TestType = (i32, String, bool);
+            let Err(value) = TestType::try_from_js(&value, context) else {
+                return false;
+            };
+            assert!(value.to_string().contains("TypeError"));
+            true
+        }),
+        TestAction::assert_with_op(indoc!(r#"[42, "hello"]"#), |value, context| {
+            type TestType = (i32, String, bool);
+            let Err(value) = TestType::try_from_js(&value, context) else {
+                return false;
+            };
+            assert!(value.to_string().contains("TypeError"));
+            true
+        }),
+    ]);
+}
+
 #[test]
 fn value_into_map() {
     use boa_engine::{run_test_actions, TestAction};

core/engine/src/value/conversions/try_from_js/tuples.rs

@@ -0,0 +1,41 @@
+//! Implementation of [`TryFromJs`] for tuples.
+//!
+//! Tuples are converted from a JavaScript array, using similar semantics to `TypeScript` tuples:
+//!     - If the tuple is shorter than the array, the extra elements are ignored.
+//!     - If the tuple is longer than the array, the extra elements are `undefined`.
+//!     - If the array is empty, all elements are `undefined`.
+//!
+//! A tuple of size 0 (unit type) does not implement [`TryFromJs`].
+
+use crate::value::JsValue;
+use crate::{Context, JsResult};
+
+use super::TryFromJs;
+
+macro_rules! impl_try_from_js_for_tuples {
+    ($($name:ident),*) => {
+        impl<$($name: TryFromJs),*> TryFromJs for ($($name,)*) {
+            fn try_from_js(value: &JsValue, context: &mut Context) -> JsResult<Self> {
+                let vec: Vec<JsValue> = value.try_js_into(context)?;
+                let mut iter = vec.into_iter();
+
+                Ok((
+                    $(
+                        $name::try_from_js(&iter.next().unwrap_or_else(JsValue::undefined), context)?,
+                    )*
+                ))
+            }
+        }
+    };
+}
+
+impl_try_from_js_for_tuples!(A);
+impl_try_from_js_for_tuples!(A, B);
+impl_try_from_js_for_tuples!(A, B, C);
+impl_try_from_js_for_tuples!(A, B, C, D);
+impl_try_from_js_for_tuples!(A, B, C, D, E);
+impl_try_from_js_for_tuples!(A, B, C, D, E, F);
+impl_try_from_js_for_tuples!(A, B, C, D, E, F, G);
+impl_try_from_js_for_tuples!(A, B, C, D, E, F, G, H);
+impl_try_from_js_for_tuples!(A, B, C, D, E, F, G, H, I);
+impl_try_from_js_for_tuples!(A, B, C, D, E, F, G, H, I, J);