Covers decorator and plugin

Normally, lines in source files are marked as "covered" by coverage.py as long as they are executed. However, a unit test is normally only intended to test one function, not other functions called further down the stack.

Example:

def a():
   b()
   return 1

def b():
   return 2

def test_a():
   assert a() == 1

In this situation, test_a is only intended to test a, but coverage.py will also mark b as covered code.

This new plugin will only count lines that are explicitly marked as being covered. For example:

@covers('a')
def test_a():
   assert a() == 1

Now coverage will only report lines inside a as being executed, and nothing in b.

Requires

• coverage

To run

coverage run main.py
coverage report
coverage html

You should see in the report that only lines in foo are marked as covered.