Documentation of the debt ratings of the Tech Debt Tracker extension for VSCode.
Ratings range from A (best) to E (worse). A function rated A is less likely to receive a bug fix in the future than a function rated B, etc.
The debt ratings are computed by an algorithm trained to estimate the likelihood of code receiving a bug fix in the future based on its metrics. This analysis is done on a combination of open & closed source repositories which use semantic commit messages.
We checkout the state of the repositories 2 months ago, parse and rate all the functions, and then look at the commit history since then. We look out for commit messages prefixed with fix: and check which functions were modified by these commits.
This is what gives us the relative likelihood of functions receiving bug fixes in the near future based on their debt rating.
Note that these estimates are just to give you a sense of the impact of badly rated code, they're not meant to be treated as scientific predictions and you should always apply your best judgement. They're likely to change over time because we're continuously expanding our dataset and refining our algorithms.