Status line length miscalculation

[zajosk]

When multiple tests are in a single test file, the test result progress bar gets printed for each test in the file, when using pytest-sugar in a windows powershell terminal. Example output:

Command:

pytest .\tests\test_1.py

Output:

Test session starts (platform: win32, Python 3.8.5, pytest 6.1.1, pytest-sugar 0.9.4)  
rootdir: ..., configfile: pytest.ini
plugins: forked-1.3.0, mock-3.3.1, pspec-0.0.4, sugar-0.9.4, xdist-2.1.0
collecting ... 
 test_1.py ✓                                                         25% ██▌       
 test_1.py ✓✓                                                        50% █████     
 test_1.py ✓✓✓                                                       75% ███████▌  
 test_1.py ✓✓✓✓                                                     100% ██████████

Results (0.30s):
       4 passed

The progressbar is rendered so, that it ends right on the right window margin (last character is used by the progressbar)

I could get it fixed locally by either setting LEN_RIGHT_MARGIN to 1 or inside SugarTerminalReporter.insert_progress by adding 1 less space (num_spaces -1), but I don't know, if these are the correct fixes for the issue.

I believe some part of the calculation of number of needed spaces to insert into the status line is broken, because for in test runs with errors the lines with "-" or "=" padding are always 1 character shorter than the line with the status line