A simple spinning wheel

spinning_wheel.sh

#!/usr/bin/env bash
# ShellChecked with no issues detected

set -eu
set -o pipefail

spinning_wheel() {
    local spinning=("|" "/" "-" "\\")
    local i=0

    trap spinning_complete SIGINT SIGTERM

    while true; do
        echo -ne "\b${spinning[$i]}"
        sleep 0.2
        i=$(((i + 1) % ${#spinning[@]}))
    done
}

spinning_complete() {
    echo -ne "\b\u2714 "
    exit 0
}

start_spinning_wheel() {
    spinning_wheel &
    spinning_wheel_pid=$!
    # spinning_wheel should have a chance to run and install its signal handler
    sleep 0.1
}

stop_spinning_wheel() {
    if [ -n "$spinning_wheel_pid" ]; then
        kill -SIGTERM $spinning_wheel_pid
        wait $spinning_wheel_pid #2> /dev/null
    fi
}

test_spinning_wheel() {
    echo -n "Test:  "
    for _ in {1..3}; do
        start_spinning_wheel
        # Do something
        eval "$1"
        stop_spinning_wheel
    done
    echo ""
}

trap stop_spinning_wheel SIGINT SIGTERM

test_spinning_wheel "sleep 1"