Data Validation

This example shows how to validate API responses using schemas (Zod, Valibot) via adapters.

Unireq Code

import { client, validate } from '@unireq/core';
import { http, parse } from '@unireq/http';
import { z } from 'zod';

// 1. Define a Zod schema
const UserSchema = z.object({
  id: z.number(),
  name: z.string(),
  email: z.string().email(),
});

// 2. Create an adapter (or import from a lib)
const zodAdapter = () => (schema, data) => {
  const result = schema.safeParse(data);
  if (!result.success) {
    throw new Error(result.error.message);
  }
  return result.data;
};

// 3. Use the validate() policy
const api = client(
  http('https://jsonplaceholder.typicode.com'),
  parse.json(),
  validate(UserSchema, zodAdapter())
);

try {
  // response.data is now typed as z.infer<typeof UserSchema>
  const response = await api.get('/users/1');
  console.log(response.data.email);
} catch (error) {
  console.error('Validation failed:', error);
}

Comparison with Axios

Axios

Axios does not validate data. You must do it manually after the request.

const response = await axios.get('https://jsonplaceholder.typicode.com/users/1');

try {
  const user = UserSchema.parse(response.data);
  console.log(user.email);
} catch (error) {
  console.error('Validation failed:', error);
}

Differences

1. Integration: With Unireq, validation is part of the request pipeline. If validation fails, the request is considered failed (and can be intercepted or logged as such).
2. Automatic Typing: The validate policy automatically infers the return type of api.get() based on the schema. No need to pass generics manually.
3. Agnostic: Unireq uses an adapter pattern, so you can use Zod, Valibot, ArkType, or any other validation library.

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