scripts-to-rule-them-all (#174)

Reviewed-on: #174
Co-authored-by: sneak <sneak@sneak.berlin>
Co-committed-by: sneak <sneak@sneak.berlin>

script/fmt-check

@@ -0,0 +1,17 @@
+#!/bin/sh
+# script/fmt-check: check formatting (read-only). Same scope as
+# script/fmt, but fails instead of writing.
+set -eu
+
+ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
+
+main() {
+    cd "$ROOT"
+    if [ -n "$(gofmt -l .)" ]; then
+        echo "Files not formatted:"
+        gofmt -l .
+        exit 1
+    fi
+}
+
+main "$@"