No coverage data is collected for installed package when py.test is run in the project's root directory

[jck]

If I have a package(and pytest-cov) installed in a virtualenv, and I run pytest-cov from the project's root directory(which has the package folder), then no coverage data is collected.

[ionelmc]

Hey, I need more details to figure out what's going on:

• how do you run pytest
• pytest configuration (tox.ini/setup.cfg/pytest.ini)
• coverage configuration (.coveragerc)

[jck]

Steps to reproduce the bug:

• clone https://github.com/jck/mylib
• create fresh virtualenv
• pip install pytest-cov
• pip install .
• py.test --cov mylib

~/t/mylib git:master ❯❯❯ pip freeze                                                                                                                                                          ✱ ◼ v:7573fdbc6e567b2 
coverage==4.0.2
mylib==0.1.0
py==1.4.30
pytest==2.8.2
pytest-cov==2.2.0
wheel==0.24.0
~/t/mylib git:master ❮❮❮ py.test --cov mylib                                                                                                                                                 ✱ ◼ v:7573fdbc6e567b2 
=============================================================================================== test session starts ================================================================================================
platform linux -- Python 3.5.0, pytest-2.8.2, py-1.4.30, pluggy-0.3.1
rootdir: /home/jck/tmp/mylib, inifile: 
plugins: cov-2.2.0
collected 1 items 

tests/test_mylib.py .Coverage.py warning: No data was collected.

---------------------------------------------------------------------------------- coverage: platform linux, python 3.5.0-final-0 ----------------------------------------------------------------------------------
Name                Stmts   Miss  Cover
---------------------------------------
mylib/__init__.py       7      7     0%

============================================================================================= 1 passed in 0.01 seconds =============================================================================================
~/t/mylib git:master ❯❯❯ cd tests                                                                                                                                                            ✱ ◼ v:7573fdbc6e567b2 
~/t/m/tests git:master ❮❮❮ py.test --cov mylib                                                                                                                                               ✱ ◼ v:7573fdbc6e567b2 
=============================================================================================== test session starts ================================================================================================
platform linux -- Python 3.5.0, pytest-2.8.2, py-1.4.30, pluggy-0.3.1
rootdir: /home/jck/tmp/mylib, inifile: 
plugins: cov-2.2.0
collected 1 items 

test_mylib.py .
---------------------------------------------------------------------------------- coverage: platform linux, python 3.5.0-final-0 ----------------------------------------------------------------------------------
Name                                                                                               Stmts   Miss  Cover
----------------------------------------------------------------------------------------------------------------------
/home/jck/.local/share/virtualenvs/7573fdbc6e567b2/lib/python3.5/site-packages/mylib/__init__.py       7      2    71%

============================================================================================= 1 passed in 0.01 seconds =============================================================================================

[ionelmc]

Seems to be working as expected for me:

============================================================================================================ test session starts ============================================================================================================
platform linux -- Python 3.5.0, pytest-2.8.2, py-1.4.30, pluggy-0.3.1
rootdir: /home/ionel/sandbox/mylib, inifile:
plugins: cov-2.2.0
collected 1 items

tests/test_mylib.py .
---------------------------------------------------------------------------------------------- coverage: platform linux, python 3.5.0-final-0 -----------------------------------------------------------------------------------------------
Name                                                                  Stmts   Miss  Cover
-----------------------------------------------------------------------------------------
.ve/lib/python3.5/codecs.py                                             398    389     2%
.ve/lib/python3.5/encodings/__init__.py                                  65     54    17%
.ve/lib/python3.5/site-packages/_pytest/_argcomplete.py                  35     34     3%
.ve/lib/python3.5/site-packages/_pytest/assertion/__init__.py            81     45    44%
.ve/lib/python3.5/site-packages/_pytest/assertion/newinterpret.py       268    200    25%
.ve/lib/python3.5/site-packages/_pytest/assertion/reinterpret.py         36     13    64%
.ve/lib/python3.5/site-packages/_pytest/assertion/rewrite.py            523    373    29%
.ve/lib/python3.5/site-packages/_pytest/assertion/util.py               222    202     9%
.ve/lib/python3.5/site-packages/_pytest/cacheprovider.py                137    103    25%
.ve/lib/python3.5/site-packages/_pytest/capture.py                      308    250    19%
.ve/lib/python3.5/site-packages/_pytest/config.py                       759    632    17%
.ve/lib/python3.5/site-packages/_pytest/doctest.py                      146    142     3%
.ve/lib/python3.5/site-packages/_pytest/genscript.py                     81     78     4%
.ve/lib/python3.5/site-packages/_pytest/helpconfig.py                    95     87     8%
.ve/lib/python3.5/site-packages/_pytest/junitxml.py                     178    176     1%
.ve/lib/python3.5/site-packages/_pytest/main.py                         511    292    43%
.ve/lib/python3.5/site-packages/_pytest/mark.py                         160    152     5%
.ve/lib/python3.5/site-packages/_pytest/monkeypatch.py                  115    103    10%
.ve/lib/python3.5/site-packages/_pytest/nose.py                          42     28    33%
.ve/lib/python3.5/site-packages/_pytest/pastebin.py                      58     57     2%
.ve/lib/python3.5/site-packages/_pytest/pdb.py                           78     71     9%
.ve/lib/python3.5/site-packages/_pytest/python.py                      1390   1073    23%
.ve/lib/python3.5/site-packages/_pytest/resultlog.py                     84     82     2%
.ve/lib/python3.5/site-packages/_pytest/runner.py                       333    223    33%
.ve/lib/python3.5/site-packages/_pytest/skipping.py                     212    182    14%
.ve/lib/python3.5/site-packages/_pytest/terminal.py                     439    325    26%
.ve/lib/python3.5/site-packages/_pytest/tmpdir.py                        62     55    11%
.ve/lib/python3.5/site-packages/_pytest/unittest.py                     144    137     5%
.ve/lib/python3.5/site-packages/_pytest/vendored_packages/pluggy.py     413    277    33%
.ve/lib/python3.5/site-packages/mylib/__init__.py                         7      2    71%
.ve/lib/python3.5/site-packages/pkg_resources/__init__.py              1607   1604     1%
.ve/lib/python3.5/site-packages/py/_apipkg.py                           138    109    21%
.ve/lib/python3.5/site-packages/py/_builtin.py                          188    177     6%
.ve/lib/python3.5/site-packages/py/_code/code.py                        523    498     5%
.ve/lib/python3.5/site-packages/py/_code/source.py                      285    165    42%
.ve/lib/python3.5/site-packages/py/_error.py                             50     45    10%
.ve/lib/python3.5/site-packages/py/_io/saferepr.py                       49     28    43%
.ve/lib/python3.5/site-packages/py/_io/terminalwriter.py                234    151    35%
.ve/lib/python3.5/site-packages/py/_path/common.py                      244    153    37%
.ve/lib/python3.5/site-packages/py/_path/local.py                       628    490    22%
.ve/lib/python3.5/site-packages/py/_std.py                               11      5    55%
.ve/lib/python3.5/site-packages/py/_xmlgen.py                           170    168     1%
.ve/lib/python3.5/site-packages/pytest_cov/engine.py                    156    145     7%
.ve/lib/python3.5/site-packages/pytest_cov/plugin.py                    101     90    11%
tests/test_mylib.py                                                       4      0   100%
-----------------------------------------------------------------------------------------
TOTAL                                                                 11768   9665    18%

========================================================================================================= 1 passed in 1.16 seconds ==========================================================================================================

[ionelmc]

Note the .ve/lib/python3.5/site-packages/mylib/__init__.py 7 2 71%

I think what you need here is a path mapping in .coveragerc

[ionelmc]

To be honest I have never figured out how to get that damn mapping to work (https://coverage.readthedocs.org/en/latest/config.html#paths) so I always have two envs, one for normal runs and one for coverage runs (where something alone the lines of pip install -e . happens - editable installs). See this.

[jck]

What was your PWD and command from the output you posted?

[ionelmc]

I was in the root of the repo (/home/ionel/sandbox/mylib). ​ ​​

[ionelmc]

You also appear to have the expected result:

~/t/m/tests git:master ❮❮❮ py.test --cov mylib                                                                                                                                                 ◼ v:7573fdbc6e567b2 
=============================================================================================== test session starts ================================================================================================
platform linux -- Python 3.5.0, pytest-2.8.2, py-1.4.30, pluggy-0.3.1
rootdir: /home/jck/tmp/mylib, inifile: 
plugins: cov-2.2.0
collected 1 items 

test_mylib.py .
---------------------------------------------------------------------------------- coverage: platform linux, python 3.5.0-final-0 ----------------------------------------------------------------------------------
Name                                                                                               Stmts   Miss  Cover
----------------------------------------------------------------------------------------------------------------------
/home/jck/.local/share/virtualenvs/7573fdbc6e567b2/lib/python3.5/site-packages/mylib/__init__.py       7      2    71%

============================================================================================= 1 passed in 0.01 seconds =============================================================================================

[ionelmc]

I think this can be closed. I don't think there's a way to solve this in pytest-cov. Maybe report issue with paths mapping at https://bitbucket.org/ned/coveragepy/ ?

[jck]

I have the expected result when my pwd is the tests subdirectory.

When I run from the project root, I get nothing.

[ionelmc]

Ok, and if you run just py.test --cov (no package name) in the root?