Thank you for your honest feedback!

1. I've updated the description to be clearer about checking for EXACT lengths and EXACT occurences of streaks
2. 'HHHHHH' would therefore be 0 matches for L=3, as it is a streak of length L=6.
3. Added additional sample tests that include sequences longer than L
4. Added a range of simple fixed tests
5. Reduced the number of random tests to 500

Hope that helps! :)

Thank you for pointing that out! Should be fixed now :)