fester

Your git log is a pain diary. This reads it.

fester scans your git history for fix-type commits and ranks files by how often — and how recently — they've caused pain.

Usage

npx fester                                  # scan last 90 days
npx fester --days 30                        # custom window
npx fester --since 2024-01-01 --until 2024-03-31  # explicit date range
npx fester --top 10                         # show top 10 only
npx fester --author "jane"                  # only fixes authored by matching name
npx fester --compare                        # compare this window vs the preceding one
npx fester --report                         # generate + open HTML report
npx fester --json | jq .                    # pipe-friendly JSON
npx fester --path /path/to/repo             # run on another repo

How it works

1. Reads git log for the given window
2. Classifies commits by subject line: fix:, hotfix:, revert:, bug:, patch:
3. Scores each file using a recency-weighted formula:

   score(file) = Σ weight[type] / (days_since + 1)

4. Normalises scores 0–100 relative to the worst offender
5. Detects trend by comparing first vs second half of the window

Score weights

| type | weight | |---------|--------| | revert | 3.0 | | hotfix | 2.5 | | fix | 2.0 | | bug | 1.5 | | patch | 1.0 |

Comparing windows

--compare scores the current window and the immediately preceding window of equal length, then shows which files got worse or better:

npx fester --compare              # last 90 days vs the 90 days before that
npx fester --days 30 --compare    # last 30 days vs the 30 days before that

No AI. No estimates. Pure git math.

MIT