TryFromJs from JsMap for HashMap & BtreeMap

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

@@ -559,3 +559,26 @@ fn value_into_map() {
         }),
     ]);
 }
+
+#[test]
+fn js_map_into_rust_map() -> JsResult<()> {
+    use boa_engine::Source;
+    use std::collections::{BTreeMap, HashMap};
+
+    let js_code = "new Map([['a', 1], ['b', 3], ['aboba', 42024]])";
+    let mut context = Context::default();
+
+    let js_value = context.eval(Source::from_bytes(js_code))?;
+
+    let hash_map = HashMap::<String, i32>::try_from_js(&js_value, &mut context)?;
+    let btree_map = BTreeMap::<String, i32>::try_from_js(&js_value, &mut context)?;
+
+    let expect = vec![("a".into(), 1), ("aboba".into(), 42024), ("b".into(), 3)];
+
+    let expected_hash_map: HashMap<String, _> = expect.iter().cloned().collect();
+    assert_eq!(expected_hash_map, hash_map);
+
+    let expected_btree_map: BTreeMap<String, _> = expect.iter().cloned().collect();
+    assert_eq!(expected_btree_map, btree_map);
+    Ok(())
+}

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

@@ -3,6 +3,9 @@
 use std::collections::{BTreeMap, HashMap};
 use std::hash::Hash;
 
+use boa_macros::js_str;
+
+use crate::object::{JsArray, JsMap};
 use crate::value::TryFromJs;
 use crate::{Context, JsNativeError, JsResult, JsValue};
 
@@ -18,6 +21,21 @@ where
                 .into());
         };
 
+        // JsMap case
+        if let Ok(js_map) = JsMap::from_object(object.clone()) {
+            let mut map = Self::default();
+            let f = |key, value, context: &mut _| {
+                map.insert(
+                    K::try_from_js(&key, context)?,
+                    V::try_from_js(&value, context)?,
+                );
+                Ok(())
+            };
+            for_each_elem_in_js_map(&js_map, f, context)?;
+            return Ok(map);
+        }
+
+        // key-valued JsObject case:
         let keys = object.__own_property_keys__(context)?;
 
         keys.into_iter()
@@ -47,6 +65,21 @@ where
                 .into());
         };
 
+        // JsMap case
+        if let Ok(js_map) = JsMap::from_object(object.clone()) {
+            let mut map = Self::default();
+            let f = |key, value, context: &mut _| {
+                map.insert(
+                    K::try_from_js(&key, context)?,
+                    V::try_from_js(&value, context)?,
+                );
+                Ok(())
+            };
+            for_each_elem_in_js_map(&js_map, f, context)?;
+            return Ok(map);
+        }
+
+        // key-valued JsObject case:
         let keys = object.__own_property_keys__(context)?;
 
         keys.into_iter()
@@ -62,3 +95,44 @@ where
             .collect()
     }
 }
+
+fn for_each_elem_in_js_map<F>(js_map: &JsMap, mut f: F, context: &mut Context) -> JsResult<()>
+where
+    F: FnMut(JsValue, JsValue, &mut Context) -> JsResult<()>,
+{
+    let unexp_obj_err = || {
+        JsResult::Err(
+            JsNativeError::typ()
+                .with_message("MapIterator return unexpected object")
+                .into(),
+        )
+    };
+
+    let iter = js_map.entries(context)?;
+    loop {
+        let next = iter.next(context)?;
+        let Some(iter_obj) = next.as_object() else {
+            return unexp_obj_err();
+        };
+
+        let done = iter_obj.get(js_str!("done"), context)?;
+        let Some(done) = done.as_boolean() else {
+            return unexp_obj_err();
+        };
+        if done {
+            break;
+        }
+
+        let value = iter_obj.get(js_str!("value"), context)?;
+        let Some(js_obj) = value.as_object() else {
+            return unexp_obj_err();
+        };
+        let arr = JsArray::from_object(js_obj.clone())?;
+
+        let key = arr.at(0, context)?;
+        let value = arr.at(1, context)?;
+
+        f(key, value, context)?;
+    }
+    Ok(())
+}