Wrong test result output for missing ")" token

[alaviss]

Grammar:

module.exports = grammar({
  name: "bug",

  rules: {
    source_file: (_) => seq("(", ")"),
  },
});

Corpus corpus/error.txt:

===
Err
===

(

---

Running tests:

1 failure:

expected / actual

  1. Err:

    (source_file
      (MISSING "))
)

As you can see, the closing " is missing and the associated ) as well.

Expected output:

1 failure:

expected / actual

  1. Err:

    (source_file
      (MISSING ")"))
)

Testing against corpus updated with -u also fails:

================================================================================
Err
================================================================================

(

--------------------------------------------------------------------------------

(source_file
  (MISSING "))

Output:

  err:
    ✗ Err

1 failure:

expected / actual

  1. Err:

    (source_file
      (MISSING "))

Surprisingly, no "expected/actual" diff here, just that this was "invalid".

[Plentywolf]

Invalid?

[alaviss]

The test was marked as a fail even though the output is identical to the expected result.