Implement `Object.keys` and `Object.entries` (#1471)

Co-authored-by: jedel1043 <jedel0124@gmail.com>

boa/src/builtins/object/mod.rs

@@ -18,12 +18,14 @@ use crate::{
     object::{
         ConstructorBuilder, Object as BuiltinObject, ObjectData, ObjectInitializer, PROTOTYPE,
     },
-    property::{Attribute, DescriptorKind, PropertyDescriptor},
+    property::{Attribute, DescriptorKind, PropertyDescriptor, PropertyNameKind},
     symbol::WellKnownSymbols,
     value::{JsValue, Type},
     BoaProfiler, Context, Result,
 };
 
+use super::Array;
+
 pub mod for_in_iterator;
 #[cfg(test)]
 mod tests;
@@ -61,6 +63,8 @@ impl BuiltIn for Object {
         .static_method(Self::define_properties, "defineProperties", 2)
         .static_method(Self::assign, "assign", 2)
         .static_method(Self::is, "is", 2)
+        .static_method(Self::keys, "keys", 1)
+        .static_method(Self::entries, "entries", 1)
         .static_method(
             Self::get_own_property_descriptor,
             "getOwnPropertyDescriptor",
@@ -541,8 +545,6 @@ impl Object {
     /// [spec]: https://tc39.es/ecma262/#sec-object.assign
     /// [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/assign
     pub fn assign(_: &JsValue, args: &[JsValue], context: &mut Context) -> Result<JsValue> {
-        //
-        //
         // 1. Let to be ? ToObject(target).
         let to = args
             .get(0)
@@ -582,4 +584,62 @@ impl Object {
         // 4. Return to.
         Ok(to.into())
     }
+
+    /// `Object.keys( target )`
+    ///
+    /// This method returns an array of a given object's own enumerable
+    /// property names, iterated in the same order that a normal loop would.
+    ///
+    /// More information:
+    ///  - [ECMAScript reference][spec]
+    ///  - [MDN documentation][mdn]
+    ///
+    /// [spec]: https://tc39.es/ecma262/#sec-object.keys
+    /// [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/keys
+    pub fn keys(_: &JsValue, args: &[JsValue], context: &mut Context) -> Result<JsValue> {
+        // 1. Let obj be ? ToObject(target).
+        let obj = args
+            .get(0)
+            .cloned()
+            .unwrap_or_default()
+            .to_object(context)?;
+
+        // 2. Let nameList be ? EnumerableOwnPropertyNames(obj, key).
+        let name_list = obj.enumerable_own_property_names(PropertyNameKind::Key, context)?;
+
+        // 3. Return CreateArrayFromList(nameList).
+        let result = Array::create_array_from_list(name_list, context);
+
+        Ok(result.into())
+    }
+
+    /// `Object.entries( target )`
+    ///
+    /// This method returns an array of a given object's own enumerable string-keyed property [key, value] pairs.
+    /// This is the same as iterating with a for...in loop,
+    /// except that a for...in loop enumerates properties in the prototype chain as well).
+    ///
+    /// More information:
+    ///  - [ECMAScript reference][spec]
+    ///  - [MDN documentation][mdn]
+    ///
+    /// [spec]: https://tc39.es/ecma262/#sec-object.entries
+    /// [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/entries
+    pub fn entries(_: &JsValue, args: &[JsValue], context: &mut Context) -> Result<JsValue> {
+        // 1. Let obj be ? ToObject(target).
+        let obj = args
+            .get(0)
+            .cloned()
+            .unwrap_or_default()
+            .to_object(context)?;
+
+        // 2. Let nameList be ? EnumerableOwnPropertyNames(obj, key+value).
+        let name_list =
+            obj.enumerable_own_property_names(PropertyNameKind::KeyAndValue, context)?;
+
+        // 3. Return CreateArrayFromList(nameList).
+        let result = Array::create_array_from_list(name_list, context);
+
+        Ok(result.into())
+    }
 }

boa/src/object/internal_methods.rs

@@ -6,8 +6,9 @@
 //! [spec]: https://tc39.es/ecma262/#sec-ordinary-object-internal-methods-and-internal-slots
 
 use crate::{
+    builtins::Array,
     object::{GcObject, Object, ObjectData},
-    property::{DescriptorKind, PropertyDescriptor, PropertyKey},
+    property::{DescriptorKind, PropertyDescriptor, PropertyKey, PropertyNameKind},
     value::{JsValue, Type},
     BoaProfiler, Context, Result,
 };
@@ -881,6 +882,65 @@ impl GcObject {
         Ok(list)
     }
 
+    /// It is used to iterate over names of object's keys.
+    ///
+    /// More information:
+    /// - [EcmaScript reference][spec]
+    ///
+    /// [spec]: https://tc39.es/ecma262/#sec-enumerableownpropertynames
+    pub(crate) fn enumerable_own_property_names(
+        &self,
+        kind: PropertyNameKind,
+        context: &mut Context,
+    ) -> Result<Vec<JsValue>> {
+        // 1. Assert: Type(O) is Object.
+        // 2. Let ownKeys be ? O.[[OwnPropertyKeys]]().
+        let own_keys = self.own_property_keys();
+        // 3. Let properties be a new empty List.
+        let mut properties = vec![];
+
+        // 4. For each element key of ownKeys, do
+        for key in own_keys {
+            // a. If Type(key) is String, then
+            if let PropertyKey::String(key_str) = &key {
+                // i. Let desc be ? O.[[GetOwnProperty]](key).
+                let desc = self.__get_own_property__(&key);
+                // ii. If desc is not undefined and desc.[[Enumerable]] is true, then
+                if let Some(desc) = desc {
+                    if desc.expect_enumerable() {
+                        // 1. If kind is key, append key to properties.
+                        if let PropertyNameKind::Key = kind {
+                            properties.push(key_str.clone().into())
+                        }
+                        // 2. Else,
+                        else {
+                            // a. Let value be ? Get(O, key).
+                            let value = self.get(key.clone(), context)?;
+                            // b. If kind is value, append value to properties.
+                            if let PropertyNameKind::Value = kind {
+                                properties.push(value)
+                            }
+                            // c. Else,
+                            else {
+                                // i. Assert: kind is key+value.
+                                // ii. Let entry be ! CreateArrayFromList(« key, value »).
+                                let key_val = key_str.clone().into();
+                                let entry =
+                                    Array::create_array_from_list([key_val, value], context);
+
+                                // iii. Append entry to properties.
+                                properties.push(entry.into());
+                            }
+                        }
+                    }
+                }
+            }
+        }
+
+        // 5. Return properties.
+        Ok(properties)
+    }
+
     pub(crate) fn length_of_array_like(&self, context: &mut Context) -> Result<usize> {
         // 1. Assert: Type(obj) is Object.
         // 2. Return ℝ(? ToLength(? Get(obj, "length"))).

boa/src/property/mod.rs

@@ -662,3 +662,10 @@ impl PartialEq<&str> for PropertyKey {
         }
     }
 }
+
+#[derive(Debug, Clone, Copy)]
+pub(crate) enum PropertyNameKind {
+    Key,
+    Value,
+    KeyAndValue,
+}