fix(repl): don't hang on unpaired braces (#8151)

Previously, entering a single ']' would cause repl to forever accepting
new lines, due to that `ValidationResult::Invalid` would actually be
consumed by the editor itself while continue building the lines. Instead
we should mark it as `Valid` and send the bad input for evaluation to
get the proper error from V8.

Before:
```
> ]
(you can keep entering new line here, and it will never consume input
until you Ctrl-C)
```

After:
```
> ]
Uncaught SyntaxError: Unexpected token ']'
>
```

1 files changed, 4 insertions, 5 deletions

diff --git a/cli/repl.rs b/cli/repl.rs
index 1cc866a6f..b2ea32670 100644
--- a/cli/repl.rs
+++ b/cli/repl.rs
@@ -171,11 +171,10 @@ impl Validator for Helper {
               left
             ))))
           }
-          (None, c) => {
-            return Ok(ValidationResult::Invalid(Some(format!(
-              "Mismatched pairs: {:?} is unpaired",
-              c
-            ))))
+          (None, _) => {
+            // While technically invalid when unpaired, it should be V8's task to output error instead.
+            // Thus marked as valid with no info.
+            return Ok(ValidationResult::Valid(None));
           }
         },
         _ => {}