node /bin/bg cordova run

bg.js

/* jshint esversion: 6,-W097, -W040, node: true, expr: true, undef: true */
const /* utils */
    { max, round }= Math,
    { spawn }= require('child_process'),
    { writeFileSync, readFileSync }= require("fs");
const /* runtime arguments and cwd */
    [ cmd, ...cmd_arguments ]= process.argv.slice(2),
    cwd= process.cwd();
let iteration= -1;
const /* animation */
    ani_array= [ "|", "/", "–", "\\" ],
    ani_array_length= ani_array.length,
    incAni= function(){ iteration+= 1; if(iteration===ani_array_length){ iteration= 0; } },
    nextAni= ()=> ": "+ani_array[iteration]+(prev_data_length ? ` (${round(100*data_buffer.length/prev_data_length)}% – based on previous log file)` : "");
let mesage= [ "\x1Bc\033c", (new Date()).toString(),`Running '${cmd}' with '${cmd_arguments.join(" ")}' arguments.` ];
let data_buffer= mesage.join("\n")+"\n\n   ===   LOG   ===   \n\n";
const /* output file */
    log_file= `${cmd}.log`,
    prev_data_length= getPrevLogLength(log_file);

mesage.push("executing…");
log();
const run_cmd= spawn(cmd+(cmd==="cordova"?".cmd":""), cmd_arguments, { cwd });
mesage.push("running");
const interval= setInterval(logAni, 500);
run_cmd.stdout.on("data", function(data){ data_buffer+= data; });
run_cmd.on("error", function(err){
    data_buffer+= err&&err.toString ? err.toString() : "";
    if(interval) clearInterval(interval);
    mesage.push("error detected");
});
run_cmd.on("close", function(){
    if(interval) clearInterval(interval);
    mesage.push("done");
    try{
        writeFileSync(log_file, data_buffer);
    } catch(e) {
        mesage.push(`unable to create '${cmd}.log', see ${e}.`);
    }
    log();
});

function logAni(){
    incAni();
    log(nextAni());
}
function log(text= ""){
    console.log(mesage.join("\n")+text);
}
function getPrevLogLength(log_file){
    let data_length;
    try{
        data_length= readFileSync(log_file).toString().length;
        if(!max(data_length-data_buffer.length, 0)) return 0;
        return data_length;
    } catch (e) {
        return 0;
    }
}