Run flutter in terminal with auto refresh (recursive)

flutter.sh

#!/usr/bin/env bash
set -euo pipefail

# adb reverse tcp:4000 tcp:4000 || true

PID_FILE="/tmp/flutter.pid"
rm -f "$PID_FILE"

# https://stackoverflow.com/a/2173421
trap "trap - SIGTERM && kill -- -$$" SIGINT SIGTERM EXIT
(
    sleep 10

    while [ ! -f "$PID_FILE" ]; do
        sleep 5
    done

    echo "Starting watch"

    while true; do
        fswatch -ro ./lib --latency 1 --event Updated --event Created --event Removed | \
            xargs -n1 -I{} kill -USR1 "$(cat "$PID_FILE")"
    done
) &

flutter run --pid-file "$PID_FILE" <&0