Multi-function serverless framework command issuer.

function.ts

import {exec, spawn} from "child_process";
import * as fs from "fs";
import * as path from "path";

const indivitualUsage = "ts-node function.ts <command> [--function <function>] [--args <args list...>]";
const npmUsage = "npm run <command> -- [--function <function>] [--args <args list...>]";

const commands = [
    "webpack",
    "package",
    "deploy",
    "invoke",
    "invoke-local",
];

function isEmptyString(str: string) {
    return (!str || /^\s*$/.test(str));
}

const command = process.argv[2];
if (isEmptyString(command) || commands.indexOf(command) === -1) {
    global.console.log(npmUsage);
    process.exit(-1);
}

let isSeparate = false;
let functionName = "";
let commandArgs: string[] = [];
if (process.argv[3] === "--function") {
    isSeparate = true;
    functionName = process.argv[4];
    if (isEmptyString(functionName)) {
        global.console.log(npmUsage);
        process.exit(-1);
    }
    if (process.argv[5] === "--args") {
        commandArgs = process.argv.slice(6);
    }
} else if (process.argv[3] === "--args") {
    commandArgs = process.argv.slice(4);
}

// Function-must-provided command check.
if ((["invoke", "invoke-local"].indexOf(command) !== -1) && !isSeparate) {
    global.console.log(npmUsage);
    process.exit(-1);
}

let targetPath = "";

// Directory check.
if (isSeparate) {
    const filePath = path.join(__dirname, "functions", functionName, "src", functionName + ".ts");
    if (!fs.existsSync(filePath)) {
        global.console.error(`Specified function <${functionName}> does not exists.\nPaths searched: ${targetPath}`);
    } else {
        targetPath = path.join(__dirname, "functions", functionName, "src");
    }
}



const execServerlessCommand = command.replace(/-/g, " ");
const commandSeparator = process.platform.match(/^.*win.*$/) ? ";" : " && ";
const commandArgsString = commandArgs.join(" ");
const execCommand = `${isSeparate ? "cd \"" + targetPath  + "\\\""  +  commandSeparator : ""}serverless ${execServerlessCommand} ${isSeparate ? "--function " + functionName : ""}${commandArgsString}${isSeparate ? commandSeparator + "cd" + " " + "\"" + __dirname + "\\\"" : ""}`;
global.console.log(`Now executing & {${execCommand}}...`);

(async () => {
    if (process.platform.match(/^.*win.*$/) !== null) {
        const currentProc = spawn("powershell.exe", ["-Command", `& {${execCommand}}`], {
            cwd: __dirname,
            detached: false,
            env: process.env,
            stdio: [process.stdin, process.stdout, process.stderr],
        });
        currentProc.on("close", (code) => {
            global.console.log(`child process exited with code ${code}`);
        });
    } else {
        // TODO: test for linux.
        const currentProc = spawn("echo", [execCommand]);
        currentProc.stdout.on("data", (data) => {
            global.console.log(`${data}`);
        });
        currentProc.stderr.on("data", (data) => {
            global.console.log(`${data}`);
        });
        currentProc.on("close", (code) => {
            global.console.log(`child process exited with code ${code}`);
        });
        currentProc.stdin.end();
    }
})();

Need more elegant argument parsing.