ag -l + entr = autotest!

autotest

#!/usr/bin/env bash

# Monitors your tree and runs tests when anything changes.
#
# Run `make`, `npm test`, etc. automatically detected.
#
#   $ autotest
#
# Run a specific command on changes:
#
#   $ autotest mocha test/foo_test.js
#

trap exit INT

if [[ -f package.json ]]; then
  BUILD=${@:-npm test}
elif [[ -f Makefile ]]; then
  BUILD=${@:-make}
else
  echo "Don't know what command to run. Try: autotest [command]" >&2
  exit 1
fi

while true; do
  ag -l | entr -rcd sh -c "$BUILD"
done