Using Deno, register a command in the Windows registry to be run at startup

startup.ts

// https://github.com/DjDeveloperr/deno_win32
import { HKEY_CURRENT_USER, REG_SZ, RegDeleteKeyValueA, RegSetKeyValueA } from "https://win32.deno.dev/0.4.1/System.Registry";

const HKEY = Deno.UnsafePointer.create(BigInt(HKEY_CURRENT_USER));
const STARTUP_RUN = "Software\\Microsoft\\Windows\\CurrentVersion\\Run";

export function registerStartupRun(name: string, command: string) {
	const ffiString = new TextEncoder().encode(`${command}\0`);
	const lpData = Deno.UnsafePointer.of(ffiString);
	// https://learn.microsoft.com/en-us/windows/win32/api/winreg/nf-winreg-regsetkeyvaluea
	const error = RegSetKeyValueA(
		/*hKey*/ HKEY,
		/*lpSubKey*/ STARTUP_RUN,
		/*lpValueName*/ name,
		/*dwType*/ REG_SZ,
		/*lpData*/ lpData,
		/*cbData*/ ffiString.length,
	)
	if (error !== 0) {
		throw new Error(`RegSetKeyValueA failed with error ${error}`);
	}
}

export function deregisterStartupRun(name: string) {
	// https://learn.microsoft.com/en-us/windows/win32/api/winreg/nf-winreg-regdeletekeyvaluea
	const error = RegDeleteKeyValueA(
		/*hKey*/ HKEY,
		/*lpSubKey*/ STARTUP_RUN,
		/*lpValueName*/ name,
	);
	if (error !== 0) {
		throw new Error(`RegDeleteKeyValueA failed with error ${error}`);
	}
}