diagnostic code actions fail if "code" is "None" in helix

[mtbentley]

When mypy returns a "missing library stubs" error, like this:

test.py:3: error: Skipping analyzing "pylsp": module is installed, but missing library stubs or py.typed marker  [import-untyped]
test.py:3: note: See https://mypy.readthedocs.io/en/stable/running_mypy.html#missing-imports

pylsp-mypy parses the "code" for the 2nd line as "None" (happens here).

When I try to use a code action on that line, helix doesn't pass the "code" back, and I get the following error:

"Traceback (most recent call last):\n"
"  File \"/home/maddie/pg/t/venv/lib/python3.13/site-packages/pylsp/config/config.py\", line 39, in _hookexec\n"
"    return self._inner_hookexec(hook_name, methods, kwargs, firstresult)\n"
"           ~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\n"
"  File \"/home/maddie/pg/t/venv/lib/python3.13/site-packages/pluggy/_manager.py\", line 480, in traced_hookexec\n"
"    return outcome.get_result()\n"
"           ~~~~~~~~~~~~~~~~~~^^\n"
"  File \"/home/maddie/pg/t/venv/lib/python3.13/site-packages/pluggy/_result.py\", line 100, in get_result\n"
"    raise exc.with_traceback(exc.__traceback__)\n"
"  File \"/home/maddie/pg/t/venv/lib/python3.13/site-packages/pluggy/_result.py\", line 62, in from_call\n"
"    result = func()\n"
"  File \"/home/maddie/pg/t/venv/lib/python3.13/site-packages/pluggy/_manager.py\", line 477, in <lambda>\n"
"    lambda: oldcall(hook_name, hook_impls, caller_kwargs, firstresult)\n"
"            ~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\n"
"  File \"/home/maddie/pg/t/venv/lib/python3.13/site-packages/pluggy/_callers.py\", line 139, in _multicall\n"
"    raise exception.with_traceback(exception.__traceback__)\n"
"  File \"/home/maddie/pg/t/venv/lib/python3.13/site-packages/pluggy/_callers.py\", line 103, in _multicall\n"
"    res = hook_impl.function(*args)\n"
"  File \"/home/maddie/pg/t/venv/lib/python3.13/site-packages/pylsp_mypy/plugin.py\", line 576, in pylsp_code_actions\n"
"    code = diagnostic[\"code\"]\n"
"           ~~~~~~~~~~^^^^^^^^\n"
"KeyError: 'code'\n"

I believe this is a bug in pylsp-mypy (not helix) - the specification says diagnostic["code"] should be a string or integer.

The fix should be relatively straightforward - use an empty string when there's no code (in the lint action) or skip adding a code action if a diagnostic has no code (as it's likely an info message?) - I'd probably lean towards the latter.

[Richardk2n]

Should be fixed