Extend unnecessary-type-conversion lint to redundant bytes() calls.

Author: ABohra3

crates/pyrefly_config/src/error_kind.rs

@@ -276,7 +276,7 @@ pub enum ErrorKind {
     /// Identity comparison (`is` or `is not`) between types that are provably disjoint
     /// or between literals whose comparison result is statically known.
     UnnecessaryComparison,
-    /// Warning when calling a builtin type constructor (str, int, float, bool) on a value that is already of that type.
+    /// Warning when calling a builtin type constructor (str, int, float, bytes) on a value that is already of that type.
     UnnecessaryTypeConversion,
     /// A return or yield that can never be reached.
     /// This occurs when a return/yield follows a statement that always exits,

pyrefly/lib/alt/call.rs

@@ -1007,7 +1007,7 @@ impl<'a, Ans: LookupAnswer> AnswersSolver<'a, Ans> {
         range: TextRange,
         errors: &ErrorCollector,
     ) {
-        let builtin_names = ["str", "int", "float"];
+        let builtin_names = ["str", "int", "float", "bytes"];
         if !builtin_names
             .iter()
             .any(|name| cls.has_qname("builtins", name))

pyrefly/lib/test/unnecessary_type_conversion.rs

@@ -56,6 +56,14 @@ def f(x: Any) -> None:
 "#,
 );
 
+testcase!(
+    test_bytes_to_bytes,
+    r#"
+def f(x: bytes) -> None:
+    y = bytes(x)  # E: Unnecessary `bytes()` call; argument is already of type `bytes`
+"#,
+);
+
 testcase!(
     test_no_args_ok,
     r#"