zod-validation-error

zod-validation-error

Wrap zod validation errors in user-friendly readable messages.

Features

• User-friendly readable messages, configurable via options;
• Maintain original errors under error.details;
• Extensive tests.

Installation

npm install zod-validation-error

Requirements

• Node.js v.14+

Quick start

// create zod schema
const zodSchema = zod.object({
  id: zod.number().int().positive(),
  email: zod.string().email(),
});

// parse some invalid value
try {
  zodSchema.parse({
    id: 1,
    email: 'foobar', // note: invalid email
  });
} catch (err) {
  const validationError = fromZodError(err);
  // the error now is readable by the user
  // you may print it to console
  // or return it via an API
  console.log(validationError);
}

Motivation

Zod errors are difficult to consume for the end-user. This library wraps Zod validation errors in user-friendly readable messages that can be exposed to the outer world, while maintaining the original errors in an array for dev use.

Example

Input (from Zod)

[
  {
    "code": "too_small",
    "inclusive": false,
    "message": "Number must be greater than 0",
    "minimum": 0,
    "path": ["id"],
    "type": "number"
  },
  {
    "code": "invalid_string",
    "message": "Invalid email",
    "path": ["email"],
    "validation": "email"
  }
]

Output

Validation error: Number must be greater than 0 at "id"; Invalid email at "email"

Guides and concepts

Type-guards

zod-validation-error exposes two type-guard utilities that are used to indicate whether the supplied argument is a ValidationError.

• isValidationError(err: unknown): err is ValidationError
• isValidationErrorLike(err: unknown): err is ValidationError

What is the difference?

isValidationError is based on an instanceof comparison, whereas isValidationErrorLike is using a heuristics-based approach.

In most cases, it is recommended to use isValidationErrorLike to avoid multiple-version inconsistencies. For instance, it's possible that a dependency is using an older zod-validation-error version internally. In such case, the instanceof comparison will yield invalid results because module deduplication does not apply at npm/yarn level and the prototype is different.

Example

import { ValidationError, isValidationErrorLike } from 'zod-validation-error';

const err = new ValidationError('foobar', { details: [] });
isValidationErrorLike(err); // returns true

const invalidErr = new Error('foobar');
isValidationErrorLike(err); // returns false

Contribute

Source code contributions are most welcome. Please open a PR, ensure the linter is satisfied and all tests pass.

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License

MIT