don't unwrap parenthesized assignments in calls (#816)

Author: froydnj

fixtures/small/paren_expr_unwrap_actual.rb

@@ -37,3 +37,9 @@
 
 # Ternary without keywords
 foo (condition ? a : b)
+
+# Assignments we leave alone, for consistency with code like:
+#
+# if (var = thing)
+foo ((var = thing))
+foo(1, (var2 = thing))

fixtures/small/paren_expr_unwrap_expected.rb

@@ -37,3 +37,9 @@
 
 # Ternary without keywords
 foo(condition ? a : b)
+
+# Assignments we leave alone, for consistency with code like:
+#
+# if (var = thing)
+foo((var = thing))
+foo(1, (var2 = thing))

librubyfmt/src/format_prism.rs

@@ -4943,6 +4943,9 @@ fn is_keyword_expression(node: &prism::Node) -> bool {
         Node::BeginNode { .. } => true,
         // For completeness: other control flow that shouldn't be unwrapped
         Node::ForNode { .. } => true,
+        // Assignments to local variables can be left wrapped for consistency with
+        // wrapping assignments in `if` conditions and the like.
+        Node::LocalVariableWriteNode { .. } => true,
         _ => false,
     }
 }