I discovered some issues with the generate_filename function.

Folder structure

project
  |-- src
  |    |-- package
  |    |     \-- foo2.py
  |    \-- foo.py
  |-- data
  \-- doc

Executing generate_filename:

print(generate_filename(["/home/iceflower/project/src/"], "foo.py", "/home/iceflower/project/"))
print(generate_filename(["/home/iceflower/project/src/"], "package/foo2.py", "/home/iceflower/project/"))

Result:

src/foo.py
package/foo2.py

Expected:

src/foo.py
src/package/foo2.py

Reason:
reporter.py#L49
package/foo2.py cannot be found in the /home/iceflower/project/src/ which is obvious.
Then it will check the subfolder reporter.py#54.
But it will never found them because package/foo2.py as a filename does not exist.

Fix
Use of os.path.isfile() instead of the own function.

Other bug: the strip_prefix does not support Windows \ and Linux / separators, but the git subprocess can (will ever?) return / style, while the coverage.xml can contain the Windows style. So the prefix cannot be stripped correctly.

Fix
Replace Windows style seperator with Linux style seperators.