Decouple install/update from the rest of zxb

zxb previously relied on the script name to be passed in along with arguments to the script. Since that's no longer the case, I needed to figure out a better way of handling installing/updating zxb.

src/inc/commands.mjs

@@ -2,7 +2,6 @@ import { binfo, search, getSourceDirectories, scriptPaths, addSourceDirectory, g
 import { confirm, selection } from "./helpers.mjs";
 import { getBins, relinkBins, makeScriptExecutable } from './bins.mjs'
 import { ZXB_PATHS, get, update as updateConfig } from "./config.mjs";
-import { installLatestRelease } from "./install.mjs";
 import { version } from "./github.mjs";
 
 let commandInfo = {};
@@ -262,7 +261,11 @@ async function update() {
 	}
 
 	console.log("\nUpdating...")
-	await installLatestRelease();
+	cd(`${ZXB_PATHS.zxb}/src`);
+	const result = await $`zx install.mjs --update`;
+	if (result.exitCode !== 0) {
+		throw new Error(result);
+	}
 	updateConfig("version", latestVersion)
 	console.log("Done!")
 }

src/inc/install.mjs

@@ -3,9 +3,7 @@ const zxb = `${os.homedir()}/.zxb`
 
 /**
  * 
- * This is a standalone zx file that also exports the functions
- * that it uses so that zxb can reuse parts of
- * the code in the updater.
+ * This is a standalone zx file for installing and updating zxb.
  * 
  */
 
@@ -95,7 +93,7 @@ async function download(url) {
 	process.exit(1);
 }
 
-export async function installLatestRelease() {
+async function installLatestRelease() {
 	const releaseUrl = "https://github.com/pyronaur/zxb/releases/latest/download/latest.zip";
 
 	cd(zxb)
@@ -144,11 +142,12 @@ if (parseInt(zx_version.toString()[0]) < 7) {
  * 
  * That's why this is is a necessary side-effect:
  */
-if (process.args?._?.length === 1 && !process.args._[0].includes('zxb.mjs')) {
-
-	// Turn off verbose mode by default
-	$.verbose = argv.verbose || false;
 
+// Turn off verbose mode by default
+$.verbose = argv.verbose || false;
+if (argv.update) {
+	await installLatestRelease();
+} else {
 	await fs.ensureDir(`${zxb}/bin`);
 
 	console.log(`\nInstalling ${chalk.bold("zxb")}...\n`);