Remove unneeded return stmt and add more comments/docs

boa_engine/src/vm/completion_record.rs

@@ -1,5 +1,11 @@
+//! An implementation of a `CompletionRecord` for Boa's VM.
+
 use crate::{JsError, JsResult, JsValue};
 
+/// An implementation of the ECMAScript's `CompletionRecord` [specification] for
+/// Boa's VM output Completion and Result.
+///
+/// [specification]: https://tc39.es/ecma262/#sec-completion-record-specification-type
 #[derive(Debug, Clone)]
 pub(crate) enum CompletionRecord {
     Normal(JsValue),
@@ -14,6 +20,11 @@ impl CompletionRecord {
     }
 
     /// This function will consume the current `CompletionRecord` and return a `JsResult<JsValue>`
+    // NOTE: rustc bug around evaluating destructors that prevents this from being a const function.
+    // Related issue(s):
+    //   - https://github.com/rust-lang/rust-clippy/issues/4041
+    //   - https://github.com/rust-lang/rust/issues/60964
+    //   - https://github.com/rust-lang/rust/issues/73255
     #[allow(clippy::missing_const_for_fn)]
     pub(crate) fn consume(self) -> JsResult<JsValue> {
         match self {

boa_engine/src/vm/opcode/push/class/mod.rs

@@ -58,9 +58,9 @@ impl Operation for PushClassPrototype {
             context.vm.push(JsValue::Null);
             Ok(CompletionType::Normal)
         } else {
-            return Err(JsNativeError::typ()
+            Err(JsNativeError::typ()
                 .with_message("superclass must be a constructor")
-                .into());
+                .into())
         }
     }
 }