Statements "return (" have no coverage data

[matveypashkovskiy]

Here is an example from a project:

return (
  df
  .withColumnRenamed("a", "b")
)

if the code is modified to:

return self.reset(
  df
  .withColumnRenamed("a", "b")
)

no tests will be found for the change as DB contains no mapping info about return ( line.

Any ideas on how to fix it? Any magic pytest-cov flag maybe?

[guotin]

I tried to replicate a similar situation and ran into a weird situation. If I have some similar code and run the coverage collection with pytest --cov=. --cov-context=test and check how the coverage report looks, I get this:

So no test is recorded for the return key because there is no context for that line. But if change the source code like you did, the testname gets recorded:

I don't think I can come up with a fix for this with any pytest-cov flag. You can also check what kind of contexts your program has by setting

[html]
show_contexts = True

and checking the html report produced by coverage html

[guotin]

Update: for my example, this seems to be python version specific. The above situation is with 3.6.6 and with 3.8.5 the testname is recorded for the line in both cases. I had pytest-cov 2.11.1 and coverage 5.5 during both.