scripts/build/utils simplify exec

Using shell-based execution is always a bad idea; this thing didn't do
that via an option, but instead did it manually by constructing a shell
command so it suffers from the same diseases.

Perhaps there was need for this at some point in the past, but things
are pretty robust now, so there's no need to avoid running the command
normally.  The only thing that is needed is to add `which` which also
handles windows executable suffixes.

I tried this with a fresh clone on windows, where the tree and TS are
installed in paths that have spaces, and everything works as it should.

Author: elibarzilay

scripts/build/utils.js

@@ -9,12 +9,11 @@ const del = require("del");
 const File = require("vinyl");
 const ts = require("../../lib/typescript");
 const chalk = require("chalk");
+const which = require("which");
 const { spawn } = require("child_process");
 const { CancellationToken, CancelError, Deferred } = require("prex");
 const { Readable, Duplex } = require("stream");
 
-const isWindows = /^win/.test(process.platform);
-
 /**
  * Executes the provided command once with the supplied arguments.
  * @param {string} cmd
@@ -32,12 +31,8 @@ function exec(cmd, args, options = {}) {
         const { ignoreExitCode, cancelToken = CancellationToken.none, waitForExit = true } = options;
         cancelToken.throwIfCancellationRequested();
 
-        // TODO (weswig): Update child_process types to add windowsVerbatimArguments to the type definition
-        const subshellFlag = isWindows ? "/c" : "-c";
-        const command = isWindows ? [possiblyQuote(cmd), ...args] : [`${cmd} ${args.join(" ")}`];
-
         if (!options.hidePrompt) log(`> ${chalk.green(cmd)} ${args.join(" ")}`);
-        const proc = spawn(isWindows ? "cmd" : "/bin/sh", [subshellFlag, ...command], { stdio: waitForExit ? "inherit" : "ignore", windowsVerbatimArguments: true });
+        const proc = spawn(which.sync(cmd), args, { stdio: waitForExit ? "inherit" : "ignore" });
         const registration = cancelToken.register(() => {
             log(`${chalk.red("killing")} '${chalk.green(cmd)} ${args.join(" ")}'...`);
             proc.kill("SIGINT");
@@ -68,13 +63,6 @@ function exec(cmd, args, options = {}) {
 }
 exports.exec = exec;
 
-/**
- * @param {string} cmd
- */
-function possiblyQuote(cmd) {
-    return cmd.indexOf(" ") >= 0 ? `"${cmd}"` : cmd;
-}
-
 /**
  * @param {ts.Diagnostic[]} diagnostics
  * @param {{ cwd?: string, pretty?: boolean }} [options]
@@ -440,4 +428,4 @@ class Debouncer {
         }
     }
 }
-exports.Debouncer = Debouncer;
+exports.Debouncer = Debouncer;