From 5b7150d297dc9442dbd341ae007e47c43451d178 Mon Sep 17 00:00:00 2001
From: Sven van Heugten <sven@memcmp.org>
Date: Wed, 29 Apr 2026 07:09:46 +0200
Subject: [PATCH] Add skills

---
 skills/maintain-mutations/SKILL.md | 18 ++++++++++++++++++
 skills/write-mutations/SKILL.md    | 25 +++++++++++++++++++++++++
 2 files changed, 43 insertions(+)
 create mode 100644 skills/maintain-mutations/SKILL.md
 create mode 100644 skills/write-mutations/SKILL.md

diff --git a/skills/maintain-mutations/SKILL.md b/skills/maintain-mutations/SKILL.md
new file mode 100644
index 0000000..0563e7a
--- /dev/null
+++ b/skills/maintain-mutations/SKILL.md
@@ -0,0 +1,18 @@
+---
+name: Maintain mutations
+description: Trigger when asked to maintain mutations
+---
+
+Start with:
+
+```sh
+mutannot <path/to/test-project.fsproj> --validate
+```
+
+Fix every reported error. Re-run `mutannot <path/to/test-project.fsproj> --validate` until it succeeds with no errors.
+
+If you change mutations, you must run the changed mutations with:
+
+```sh
+mutannot <path/to/test-project.fsproj> --run <mutation id 1> <mutation id 2> <...>
+```
diff --git a/skills/write-mutations/SKILL.md b/skills/write-mutations/SKILL.md
new file mode 100644
index 0000000..97bc2ed
--- /dev/null
+++ b/skills/write-mutations/SKILL.md
@@ -0,0 +1,25 @@
+---
+name: Write mutations
+description: Trigger when asked to write mutations
+---
+
+Annotate tests with one or more mutations (`MutationCase`s) that will cause the test to fail.
+
+Example:
+
+```fs
+[<Fact>]
+[<MutationCase("calc-operator-mixup", "Calculator/Calculator.fs", 4, "value + 1", "value - 1")>]
+member _.AddOne_increments() =
+    Assert.Equal(42, Calculator.addOne 41)
+```
+
+In this example,
+
+* `calc-operator-mixup` is the mutation name,
+* `Calculator/Calculator.fs` is the path to the production code (relative to the repository root),
+* `4` is the number of the line to mutate,
+* `value + 1` is the string to find, and
+* `value - 1` is the string to replace it with.
+
+Verify your work with `mutannot <path/to/test-project.fsproj> --run <mutation id 1> <mutation id 2> <...>`.