# mutation-testing

Skill · `skill:mutation-testing`

Favz census, built 2026-10-02. Tool names and counts only. No repo names. HTML page: https://favz.co/tools/skill-mutation-testing.html

- Repos that have it now: 27
- Repos that ever had it: 34
- Still have it: 79%
- Share of census repos with any tool: 0.06%

## Repos with it, by month

From commit dates in each repo's history. The last few days always look low, because repos found later fill them in.

| Month | Repos at month end |
|---|---|
| 2025-10 | 1 |
| 2025-12 | 2 |
| 2026-01 | 4 |
| 2026-02 | 6 |
| 2026-03 | 8 |
| 2026-04 | 12 |
| 2026-05 | 17 |
| 2026-06 | 20 |
| 2026-07 | 21 |
| 2026-08 | 27 |

## Goes with

Tools found in the same repos, ranked by lift: 3× means the two show up together three times as often as chance would give. Only pairs sharing 5 or more repos.

| Tool | Kind | Repos with both | Lift |
|---|---|---|---|
| [sharp-edges](https://favz.co/tools/skill-sharp-edges.md) | Skill | 5 | 449.0× |
| [contract-testing](https://favz.co/tools/skill-contract-testing.md) | Skill | 5 | 345.4× |
| [testing](https://favz.co/tools/skill-testing.md) | Skill | 5 | 46.1× |