pylance loses link to a object if it was returned by fixture

[Akopov4]

Environment data

• Language Server version: 2024.4.1
• OS and version: linux x64
• Python version (and distribution if applicable, e.g. Anaconda): python3.8 , pip23.2.1,
• python.analysis.indexing: true
• python.analysis.typeCheckingMode: basic

Code Snippet

class Cl_1:
    def __init__(self):
       pass
    def some_f1:(self):
       pass
   

class Cl_2:
    def __init__(self):
         self.obj1=Cl_1()
     
     def some_f2:(self):
       pass


  


@fixture
def fixt_1():    
    yield Cl_2()

@fixture
def fixt_2(fixt_1):     
     yield fixt_1

def test_some_test(fixt_2):
      fixt_2.some_f2()
      fixt_2.obj1.some_f1

Repro Steps

1. XXX

Expected behavior

Test run ok. When I press CTRL+ left mouse click in any of the :
fixt_2.some_f2()
fixt_2.obj1.some_f1()

I jump into declaration of the appropriate function

Actual behavior

Test runs ok.
Inside my test:
(function) some_f2: Unknown
(function) obj1: Unknown

Logs

vscode_log.txt

XXX

Requirments

[requirements.txt](https://github.com/microsoft/pylance-release/files/14846468/requirements.txt)

XXX

[Akopov4]

I did some experiments, this issue is reproducible when the inlay hints are not visible:
"editor.inlayHints.enabled": "offUnlessPressed" or "editor.inlayHints.enabled": "off"

[bschnurr]

thank you for the issue.

yes there seems to be an issue with fixtures that use yield to return a generator.

there was a slight type in your def somef1:(self) to def somef1(self)

if you set typecheckingmode to basic you should see the errors

for now try adding annotations to the fixture usage

from pytest import fixture


class Cl_1:
    def __init__(self):
       pass
    def some_f1(self):
       pass
   

class Cl_2:
    def __init__(self):
         self.obj1=Cl_1()
     
    def some_f2(self):
       pass


@fixture
def fixt_1():    
    yield Cl_2()

@fixture
def fixt_2(fixt_1: Cl_2):     
     yield fixt_1

def test_some_test(fixt_2: Cl_2):
      fixt_2.some_f2()
      fixt_2.obj1.some_f1

on second thought maybe my annotation is wrong for this def test_some_test(fixt_2: Cl_2):

[Akopov4]

Hello, is there any movement in this investigation?

[rchiodo]

Sorry this hasn't been investigated yet.

[heejaechang]

Repro workspace for investigation:
https://github.com/heejaechang/pylance-repro/tree/main/pylance-issues/5718

[rchiodo]

This issue has been fixed in prerelease version 2026.2.105, which we've just released. You can find the changelog here: CHANGELOG.md