A simple command-line tool to start NetBSD virtual machines using QEMU with sensible defaults.
tsiry-sandratraina.com
Refactor subcommands to use Effect for error handling and asynchronous operations
1import { Data, Effect, pipe } from "effect";
2import type { VirtualMachine } from "../db.ts";
3import { getInstanceState } from "../state.ts";
4
5class VmNotFoundError extends Data.TaggedError("VmNotFoundError")<{
6 name: string;
7}> {}
8
9const findVm = (name: string) =>
10 pipe(
11 getInstanceState(name),
12 Effect.flatMap((vm) =>
13 vm ? Effect.succeed(vm) : Effect.fail(new VmNotFoundError({ name }))
14 ),
15 );
16
17const displayVm = (vm: VirtualMachine) =>
18 Effect.sync(() => {
19 console.log(vm);
20 });
21
22const handleError = (error: VmNotFoundError | Error) =>
23 Effect.sync(() => {
24 if (error instanceof VmNotFoundError) {
25 console.error(
26 `Virtual machine with name or ID ${error.name} not found.`,
27 );
28 } else {
29 console.error(`An error occurred: ${error}`);
30 }
31 Deno.exit(1);
32 });
33
34const inspectEffect = (name: string) =>
35 pipe(
36 findVm(name),
37 Effect.flatMap(displayVm),
38 Effect.catchAll(handleError),
39 );
40
41export default async function (name: string) {
42 await Effect.runPromise(inspectEffect(name));
43}