Variable type duplicated when assigned using isinstance in ternary

[audoh-tickitto]

Environment data

• Language Server version: 2021.2.0
• OS and version: Windows 10 Pro 20H2 19042.789
• Python version (& distribution if applicable, e.g. Anaconda): 3.9.1 acquired via pyenv

Expected behaviour

• Type should only appear once

Actual behaviour

• Type is duplicated:
  

Logs

N/A
(I enabled logging but didn't see any relevant output in the panel when entering the problem code; when I saved I just saw the commands run for the linter, type checker etc. I have set up)

Code Snippet / Additional information

import json
json_path = "my_json.json"
with open(json_path, "rb") as data_file:
    parsed = json.load(data_file, object_hook=json_util.object_hook)
    docs = parsed if isinstance(parsed, list) else [parsed]

[erictraut]

What's happening here is that the types in the union are list[Any] and list[Unknown]. But because you have type checking disabled, we hide any Any and Unknown type arguments under the assumption that you don't want to see those additional details. I'll look at how we can elide the seemingly-redundant type from the union when displaying it.

[audoh-tickitto]

Cool, I didn't even realise that was off by default but did wonder why I didn't see generic types! I've just enabled it.

[erictraut]

This will be fixed in the next release.

[jakebailey]

This issue has been fixed in version 2021.2.1, which we've just released. You can find the changelog here: https://github.com/microsoft/pylance-release/blob/main/CHANGELOG.md#202121-10-february-2021