@nice-code/common-errors

Docs: nicecode.io — guides, integrations, and the full API surface. Working with an AI assistant? Point it at nicecode.io/llms-common-errors.txt (just this package) or nicecode.io/llms.txt (the whole stack) — the complete, current docs flattened into plain text.

Shared error domains for Standard Schema validation errors, with Hono middleware integration.

Install

bun add @nice-code/common-errors

Peer deps: valibot (or any Standard Schema library), hono (for /hono subpath).

Validation error domain

err_validation is a @nice-code/error domain for Standard Schema validation failures. Import it to match or inspect validation errors by domain.

import { err_validation, EValidator } from "@nice-code/common-errors";

// Check if an error is a validation error
if (err_validation.isExact(caught)) {
  const hydrated = err_validation.hydrate(caught);
  const { issues } = hydrated.getContext(EValidator.standard_schema);
  // issues: readonly StandardSchemaV1.Issue[]
}

The domain exposes one error id: EValidator.standard_schema with context { issues }.

Hono middleware

Import from the /hono subpath:

import { niceSValidator, niceCatchSValidation } from "@nice-code/common-errors/hono";

niceSValidator(target, schema)

Drop-in replacement for @hono/standard-validator's sValidator that throws a NiceError instead of returning a 400 response when validation fails.

import { niceSValidator } from "@nice-code/common-errors/hono";
import * as v from "valibot";

const CreateUserSchema = v.object({
  name: v.string(),
  email: v.pipe(v.string(), v.email()),
});

app.post("/users", niceSValidator("json", CreateUserSchema), async (c) => {
  const body = c.req.valid("json"); // fully typed
  // ...
});

When validation fails, a NiceError from the err_validation domain is thrown. Use Hono's onError handler to convert it to a JSON response:

import { castNiceError } from "@nice-code/error";

app.onError((err, c) => {
  const niceError = castNiceError(err);
  return c.json(niceError.toJsonObject(), niceError.httpStatusCode as any);
});

niceCatchSValidation()

Middleware that intercepts raw @hono/standard-validator validation responses (the default { success: false, error: [...] } shape) and converts them into NiceError JSON responses. Use this when you can't replace sValidator with niceSValidator directly.

app.use(niceCatchSValidation());

// Existing sValidator usage is automatically intercepted
app.post("/data", sValidator("json", MySchema), handler);

Full Hono example

import { Hono } from "hono";
import { niceSValidator } from "@nice-code/common-errors/hono";
import { castNiceError, EErrorPackType } from "@nice-code/error";
import * as v from "valibot";

const app = new Hono();

app.onError((err, c) => {
  const niceError = castNiceError(err);
  return c.json(niceError.toJsonObject(), niceError.httpStatusCode as any);
});

const BodySchema = v.object({ message: v.string() });

app.post("/echo", niceSValidator("json", BodySchema), async (c) => {
  const { message } = c.req.valid("json");
  return c.json({ echo: message });
});