Add a pre-commit-hook

pre-commit-hook.sh

@@ -0,0 +1,27 @@
+#!/bin/sh
+# Stolen from
+# https://deaddabe.fr/blog/2021/09/29/git-pre-commit-hook-for-rust-projects/
+# Run `ln -s ../../pre-commit-hook.sh .git/hooks/pre-commit` to install
+
+set -eu
+
+if ! cargo fmt -- --check
+then
+    echo "There are some code style issues."
+    echo "Run cargo fmt first."
+    exit 1
+fi
+
+if ! cargo clippy --all-targets -- -D warnings
+then
+    echo "There are some clippy issues."
+    exit 1
+fi
+
+if ! cargo test
+then
+    echo "There are some test issues."
+    exit 1
+fi
+
+exit 0