Re-enable must_use clippy rule (#3180)

boa_engine/src/builtins/function/mod.rs

@@ -316,6 +316,7 @@ pub struct Function {
 
 impl Function {
     /// Returns the codeblock of the function, or `None` if the function is a [`NativeFunction`].
+    #[must_use]
     pub fn codeblock(&self) -> Option<&CodeBlock> {
         match &self.kind {
             FunctionKind::Native { .. } => None,
@@ -438,6 +439,7 @@ impl Function {
     }
 
     /// Gets the `Realm` from where this function originates.
+    #[must_use]
     pub const fn realm(&self) -> &Realm {
         &self.realm
     }
@@ -1128,16 +1130,19 @@ impl BoundFunction {
     }
 
     /// Get a reference to the bound function's this.
+    #[must_use]
     pub const fn this(&self) -> &JsValue {
         &self.this
     }
 
     /// Get a reference to the bound function's target function.
+    #[must_use]
     pub const fn target_function(&self) -> &JsObject {
         &self.target_function
     }
 
     /// Get a reference to the bound function's args.
+    #[must_use]
     pub fn args(&self) -> &[JsValue] {
         self.args.as_slice()
     }

boa_engine/src/builtins/iterable/mod.rs

@@ -77,60 +77,70 @@ pub struct IteratorPrototypes {
 impl IteratorPrototypes {
     /// Returns the `ArrayIteratorPrototype` object.
     #[inline]
+    #[must_use]
     pub fn array(&self) -> JsObject {
         self.array.clone()
     }
 
     /// Returns the `IteratorPrototype` object.
     #[inline]
+    #[must_use]
     pub fn iterator(&self) -> JsObject {
         self.iterator.clone()
     }
 
     /// Returns the `AsyncIteratorPrototype` object.
     #[inline]
+    #[must_use]
     pub fn async_iterator(&self) -> JsObject {
         self.async_iterator.clone()
     }
 
     /// Returns the `AsyncFromSyncIteratorPrototype` object.
     #[inline]
+    #[must_use]
     pub fn async_from_sync_iterator(&self) -> JsObject {
         self.async_from_sync_iterator.clone()
     }
 
     /// Returns the `SetIteratorPrototype` object.
     #[inline]
+    #[must_use]
     pub fn set(&self) -> JsObject {
         self.set.clone()
     }
 
     /// Returns the `StringIteratorPrototype` object.
     #[inline]
+    #[must_use]
     pub fn string(&self) -> JsObject {
         self.string.clone()
     }
 
     /// Returns the `RegExpStringIteratorPrototype` object.
     #[inline]
+    #[must_use]
     pub fn regexp_string(&self) -> JsObject {
         self.regexp_string.clone()
     }
 
     /// Returns the `MapIteratorPrototype` object.
     #[inline]
+    #[must_use]
     pub fn map(&self) -> JsObject {
         self.map.clone()
     }
 
     /// Returns the `ForInIteratorPrototype` object.
     #[inline]
+    #[must_use]
     pub fn for_in(&self) -> JsObject {
         self.for_in.clone()
     }
 
     /// Returns the `%SegmentIteratorPrototype%` object.
     #[inline]
+    #[must_use]
     #[cfg(feature = "intl")]
     pub fn segment(&self) -> JsObject {
         self.segment.clone()
@@ -378,6 +388,7 @@ pub struct IteratorRecord {
 impl IteratorRecord {
     /// Creates a new `IteratorRecord` with the given iterator object, next method and `done` flag.
     #[inline]
+    #[must_use]
     pub fn new(iterator: JsObject, next_method: JsValue) -> Self {
         Self {
             iterator,

boa_engine/src/builtins/map/ordered_map.rs

@@ -191,6 +191,7 @@ impl<V> OrderedMap<V> {
     /// Return `true` if an equivalent to `key` exists in the map.
     ///
     /// Computes in **O(1)** time (average).
+    #[must_use]
     pub fn contains_key(&self, key: &JsValue) -> bool {
         self.map.contains_key(key)
     }

boa_engine/src/builtins/promise/mod.rs

@@ -51,6 +51,7 @@ unsafe impl Trace for PromiseState {
 impl PromiseState {
     /// Gets the inner `JsValue` of a fulfilled promise state, or returns `None` if
     /// the state is not `Fulfilled`.
+    #[must_use]
     pub const fn as_fulfilled(&self) -> Option<&JsValue> {
         match self {
             Self::Fulfilled(v) => Some(v),
@@ -60,6 +61,7 @@ impl PromiseState {
 
     /// Gets the inner `JsValue` of a rejected promise state, or returns `None` if
     /// the state is not `Rejected`.
+    #[must_use]
     pub const fn as_rejected(&self) -> Option<&JsValue> {
         match self {
             Self::Rejected(v) => Some(v),

boa_engine/src/builtins/set/ordered_set.rs

@@ -122,6 +122,7 @@ impl OrderedSet {
     /// Return `true` if `value` is present in set, false otherwise.
     ///
     /// Computes in **O(n)** time (average).
+    #[must_use]
     pub fn contains(&self, value: &JsValue) -> bool {
         self.inner.contains(value)
     }

boa_engine/src/builtins/typed_array/integer_indexed_object.rs

@@ -66,6 +66,7 @@ impl IntegerIndexed {
     }
 
     /// Get the integer indexed object's byte offset.
+    #[must_use]
     pub const fn byte_offset(&self) -> u64 {
         self.byte_offset
     }
@@ -81,6 +82,7 @@ impl IntegerIndexed {
     }
 
     /// Get a reference to the integer indexed object's viewed array buffer.
+    #[must_use]
     pub const fn viewed_array_buffer(&self) -> Option<&JsObject> {
         self.viewed_array_buffer.as_ref()
     }
@@ -91,6 +93,7 @@ impl IntegerIndexed {
     }
 
     /// Get the integer indexed object's byte length.
+    #[must_use]
     pub const fn byte_length(&self) -> u64 {
         self.byte_length
     }
@@ -101,6 +104,7 @@ impl IntegerIndexed {
     }
 
     /// Get the integer indexed object's array length.
+    #[must_use]
     pub const fn array_length(&self) -> u64 {
         self.array_length
     }