Test discovery failed for pytest 4.2.0

[niksite]

Environment data

• VS Code version: 1.31.1
• Extension version (available under the Extensions sidebar): 2019.1.0
• OS and version: MacOS 10.14.3 (18D103)
• Python version (& distribution if applicable, e.g. Anaconda): 2.7.15
• Type of virtual environment used (N/A | venv | virtualenv | conda | ...): virtualenv
• Relevant/affected Python packages and their versions: pytest==4.2.0

Expected behaviour

Test discovery succeeded.

Actual behaviour

Test discovery failed:

Works well with pytest 4.0.2

Logs

Output for Python in the Output panel (View→Output, change the drop-down the upper-right of the Output panel to Python)

Test Discovery failed: 
TypeError: Cannot read property 'item' of undefined

Output from Console under the Developer Tools panel (toggle Developer Tools on under Help; turn on source maps to make any tracebacks be useful by running Enable source map support for extension debugging)

/Applications/Visual Studio Code.app/Contents/Resources/app/out/vs/workbench/workbench.main.js:2561 Test discovery error, please check the configuration settings for the tests.
t.onDidNotificationChange @ /Applications/Visual Studio Code.app/Contents/Resources/app/out/vs/workbench/workbench.main.js:2561
/Applications/Visual Studio Code.app/Contents/Resources/app/out/vs/workbench/workbench.main.js:287 [Extension Host] Python Extension: displayDiscoverStatus TypeError: Cannot read property 'item' of undefined
	at module.exports.l.parsePyTestModuleCollectionResult.t.forEach.t (/Users/sisuser/.vscode/extensions/ms-python.python-2019.1.0/out/client/extension.js:83:786559)
	at Array.forEach (<anonymous>)
	at l.parsePyTestModuleCollectionResult (/Users/sisuser/.vscode/extensions/ms-python.python-2019.1.0/out/client/extension.js:83:785904)
	at module.exports.l.getTestFiles.e.split.forEach (/Users/sisuser/.vscode/extensions/ms-python.python-2019.1.0/out/client/extension.js:83:784530)
	at Array.forEach (<anonymous>)
	at l.getTestFiles (/Users/sisuser/.vscode/extensions/ms-python.python-2019.1.0/out/client/extension.js:83:784404)
	at l.parse (/Users/sisuser/.vscode/extensions/ms-python.python-2019.1.0/out/client/extension.js:83:784191)
	at h.<anonymous> (/Users/sisuser/.vscode/extensions/ms-python.python-2019.1.0/out/client/extension.js:83:783405)
	at Generator.next (<anonymous>)
	at s (/Users/sisuser/.vscode/extensions/ms-python.python-2019.1.0/out/client/extension.js:83:781847)

[hmaerki]

This is how I could reproduce Test Discovery failed:

def test_new():
    """
    Test Doc: Line 1 ...
    """
    assert True

Pytest output is

<Module test_sample.py>
  <Function test_new>

• will be parsed correctly by Visual Studio Code

Now a add --verbose

pytest.ini:
addopts = --verbose

Pytest output is

<Module test_sample.py>
  <Function test_new>
    Test Doc: Line 1 ...

Now Visual Studio Code reports Test Discovery failed

Conclusion of the effect demonstrated above
The --verbose option changed from pytest 3.9 to 4.2: Now there is more verbose output - this seems to be valid.
However, the Visual Studio Code parser can't handle this verbosity.

[karrtikr]

Closing in favour of #3911