Unexpected SyntaxError while compiling await (() => 42)

[Corei13]

Version: Deno 2.1.7

> () => 42
[Function (anonymous)]
> await (() => 42)
Uncaught SyntaxError: Malformed arrow function parameter list
> await [() => 42]
[ [Function (anonymous)] ]
> const f = () => 42; await f
[Function: f]
> await function() { return 42 }
[Function (anonymous)]

await (() => 42) should be treated as a valid syntax.

[marvinhagemeister]

Can confirm. It doesn't reproduce in SWC and seems to only happens in repl.

[HasanAlrimawi]

This is caused by repl session fn evaluate_expression in deno\cli\tools\repl\session.rs .
If you check the value at the end of the function you'll find the error, while if you check parsed_source.diagnostics() you will get empty vector.

Which means that it's related to deno and most probably deno_core has something to do with it -> fn post_message of LocalInspectorSession in deno_core\core\inspector.rs