typed-errors.ts

/**
 * Typed error responses: declare error schemas per status, return them with
 * c.error() (payload type-checked!), and the client narrows by status.
 *
 *   bun run examples/typed-errors.ts
 */
import { Ma, mc } from "@ma/core"
import { z } from "zod"

const app = new Ma().get(
  "/users/:id",
  {
    response: z.object({ id: z.string(), name: z.string() }),
    errors: {
      404: z.object({ message: z.string() }),
      403: z.object({ message: z.string(), requiredRole: z.string() }),
    },
  },
  (c) => {
    if (c.params.id === "0") return c.error(404, { message: "no such user" })
    if (c.params.id === "1") return c.error(403, { message: "forbidden", requiredRole: "admin" })
    return { id: c.params.id, name: "Alice" }
  },
)

// mc(app) is the in-process test client — no server needed.
const client = mc(app)

for (const id of ["42", "0", "1"]) {
  const res = await client.users[":id"].get({ id })
  if (res.ok) {
    console.log(`ok:  ${res.data.name}`) // data: { id: string; name: string }
  } else if (res.status === 404) {
    console.log(`404: ${res.data.message}`) // data: { message: string }
  } else {
    console.log(`403: needs ${res.data.requiredRole}`) // data: { message: string; requiredRole: string }
  }
}