Refactor scripts (#2465)

* Refactor all kinds of scripts

* Update docs to ensure linter passes

scripts/_command.js

@@ -0,0 +1,36 @@
+"use strict"
+
+process.on("unhandledRejection", (e) => { throw e })
+
+function reportExec(e) {
+	if (!e.stdout || !e.stderr) return false
+	console.error(e.stack)
+
+	if (e.stdout && e.stdout.length) {
+		console.error(e.stdout.toString("utf-8"))
+	}
+	if (e.stderr && e.stderr.length) {
+		console.error(e.stderr.toString("utf-8"))
+	}
+
+	return true
+}
+
+exports.exec = (mod, init) => {
+	if (require.main === mod) {
+		// Skip the first tick.
+		Promise.resolve().then(init).catch((e) => {
+			// eslint-disable-next-line no-process-exit
+			if (reportExec(e)) process.exit(1)
+			else throw e
+		})
+	}
+}
+
+exports.run = async (init) => {
+	try {
+		await init()
+	} catch (e) {
+		if (!reportExec(e)) console.error(e)
+	}
+}