Table of Contents

• About
• Installation
• Usage
• Authors
• Acknowledgments

About

Zod Error converts and formats Zod Issues into a customizable error message string that can be consumed by various applications such as front end error message modals or api error messages.

Basic Usage

Zod Error converts an array of Zod Issues that look like this:

[
  {
    code: 'invalid_type',
    expected: 'string',
    received: 'undefined',
    path: ['name'],
    message: 'Required',
  },
  {
    code: 'invalid_type',
    expected: 'string',
    received: 'number',
    path: ['pets', 1],
    message: 'Expected string, received number',
  },
];

into this:

Error #1: Code: invalid_type ~ Path: name ~ Message: Required | Error #2: Code: invalid_type ~ Path: pets[1] ~ Message: Expected string, received number

Installation

Install the package using your favorite package manager:

npm install zod-error
yarn add zod-error
pnpm add zod-error

Usage

Message Format

🕓 2022-07-14T20:19:52.290Z ~ Error #1: Code: invalid_type ~ Path: ratings[0].speed ~ Message: Expected number, received string 🔥 Error #2: Code: invalid_enum_value ~ Path: position ~ Message: Invalid enum value. Expected 'C' | 'PF' | 'SF' | 'SG' | 'PG', received 'Center'🔚

| Value | Description | | --------------------------------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------- | | 🕓 2022-07-14T20:19:15.660Z ~ | Prefix | | ~ | Component delimiter | | Error #1: | Added using options.transform() | | Code: | Code label | | invalid_type | Code value | | Path: | Path label | | ratings[0].speed | Path value | | Message: | Message label | | Expected number, received string | Message value | | 🔥 | Error delimiter | | Error #2: Code: invalid_enum_value ~ Path: position ~ Message: Invalid enum value. Expected 'C' \| 'PF' \| 'SF' \| 'SG'\| 'PG', received 'Center' | Error from second ZodIssue from Issues array input | | 🔚 | Suffix |

Options

Error messages are completely customizable from label names to delimiters, prefixes, suffixes and the inclusion/exclusion of components (code, path, message). An options argument can be passed to any Zod Error function as the last argument to customize the error message.

| Property | Value | Description | | ---------- | ----------------------------------------------------------------- | ------------------------------------------------------------------------- | | code? | CodeOptions | Options to customize the code component of the error message. | | delimiter? | DelimiterOptions | Set the delimiter between error messages and between components. | | maxErrors? | number | Maximum amount of error messages to display in final concatenated string. | | message? | MessageOptions | Options to customize the message component of the error message. | | path? | PathOptions | Options to customize the code path of the error message. | | prefix? | string | Add a prefix to the start of the final concatenated message. | | suffix? | string | Add a suffix to the end of the final concatenated string. | | transform? | (params: TransformErrorParams) => string | A custom function to transform the format of each error message. |

CodeOptions

| Property | Value | Description | | ---------- | ------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------- | | enabled | boolean | Display or hide the code component of the error message. Defaults to true. | | label? | string | null | Set a custom label. Defaults to Code: . Only available if enabled is true. | | transform? | (params: TransformComponentParams) => string | A custom function to transform the format of the code component. Only available if enabled is true. |

DelimiterOptions

| Property | Value | Description | | ---------- | ------ | --------------------------------------------------------------------------------------------- | | component? | string | The delimiter between each component during the concatentation process. Defaults to ~. | | error? | string | The delimiter between each error message during the concatentation process. Defaults to \|. |

MessageOptions

| Property | Value | Description | | ---------- | ------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------- | | enabled | boolean | Display or hide the message component of the error message. Defaults to true. | | label? | string | null | Set a custom label. Defaults to Message: . Only available if enabled is true. | | transform? | (params: TransformComponentParams) => string | A custom function to transform the format of the message component. Only available if enabled is true. |

PathOptions

| Property | Value | Description | | -------------------- | ------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | | arraySquareBrackets? | boolean | Adds square brackets around index number in the path. Only available if enabled is true and type is objectNotation or breadcrumbs. Defaults to true. | | delimiter? | string | Set a custom delimeter between each path element. Only available if enabled is true and type is breadcrumbs. Defaults to >. | | enabled | boolean | Display or hide the path component of the error message. Defaults to true. | | label? | string | null | Set a custom label. Defaults to Message: . Only available if enabled is true. | | transform? | (params: TransformComponentParams) => string | A custom function to transform the format of the message component. Only available if enabled is true. | | type | 'objectNotation' | 'zodPathArray' | 'breadcrumbs' | Sets the style of the path string.objectNotation = car.wheels[1].tyre zodPathArray = ["car", "wheels", 1, "tyre"]breadcrumbs = car > wheels > [1] > tyre. |

TransformComponentParams

| Property | Value | Description | | --------- | ------ | ----------------------------------------------------------------- | | component | string | The transformed component string. Defaults to ${label}${value}. | | label | string | The label of the component. | | value | string | The value of the component. |

TransformErrorParams

| Property | Value | Description | | ---------------- | ---------- | ------------------------------------------------------------------------- | | codeComponent | string | The transformed code component string. Defaults to ${label}${value}. | | errorMessage | string | The transformed error message consisting of all components concatentated. | | index | string | The index of the current error message. | | issue | z.ZodIssue | The original ZodIssue object. | | messageComponent | string | The transformed message component string. Defaults to ${label}${value}. | | pathComponent | string | The transformed path component string. Defaults to ${label}${value}. |

Examples

There are 6 ways to consume Zod Error. generateErrorMessage(), generateError(), parse(), parseAsync(), safeParse() and safeParseAsync().

generateErrorMessage(issues: z.ZodIssue[], options?: ErrorMessageOptions): string

Formats an array of Zod Issues as a result of z.parse(), z.parseAsync(), z.safeParse() or z.safeParseAsync() and outputs as a single string. Multiple errors are concatenated into a single readable string.

import { generateErrorMessage, ErrorMessageOptions } from 'zod-error';
import { z } from 'zod';

enum Color {
  Red = 'Red',
  Blue = 'Blue',
}

const options: ErrorMessageOptions = {
  delimiter: {
    error: ' 🔥 ',
  },
  transform: ({ errorMessage, index }) => `Error #${index + 1}: ${errorMessage}`,
};

const schema = z.object({
  color: z.nativeEnum(Color),
  shape: z.string(),
  size: z.number().gt(0),
});

const data = {
  color: 'Green',
  size: -1,
};

const result = schema.safeParse(data);
if (!result.success) {
  const errorMessage = generateErrorMessage(result.error.issues, options);
  throw new Error(errorMessage);
}

Error Message:

Error #1: Code: invalid_enum_value ~ Path: color ~ Message: Invalid enum value. Expected 'Red' | 'Blue', received 'Green' 🔥 Error #2: Code: invalid_type ~ Path: shape ~ Message: Required 🔥 Error #3: Code: too_small ~ Path: size ~ Message: Number must be greater than 0

generateError(issues: z.ZodIssue[], options?: ErrorMessageOptions): Error

Formats an array of Zod Issues as a result of z.parse(), z.parseAsync(), z.safeParse() or z.safeParseAsync() and outputs as a JavaScript Error object. Multiple errors are concatenated into a single readable string.

import { ErrorMessageOptions, generateError } from 'zod-error';
import { z } from 'zod';

const options: ErrorMessageOptions = {
  maxErrors: 2,
  delimiter: {
    component: ' - ',
  },
  path: {
    enabled: true,
    type: 'zodPathArray',
    label: 'Zod Path: ',
  },
  code: {
    enabled: false,
  },
  message: {
    enabled: true,
    label: '',
  },
};

const schema = z.object({
  dates: z.object({
    purchased: z.date(),
    fulfilled: z.date(),
  }),
  item: z.string(),
  price: z.number(),
});

const data = {
  dates: { purchased: 'yesterday' },
  item: 1,
  price: '1,000',
};

try {
  schema.parse(data);
} catch (error) {
  const genericError = generateError(error, options);
  throw genericError;
}

Error Message:

Zod Path: ["dates", "purchased"] - Expected date, received string | Zod Path: ["dates", "fulfilled"] - Required

parse<T extends z.ZodTypeAny>(schema: T, data: unknown, options?: ErrorMessageOptions): T['_output']

Replaces Zod's .parse() function by replacing Zod's ZodError with a generic JavaScript Error object where the custom formatted message can be accessed on error.message.

import { ErrorMessageOptions, parse } from 'zod-error';
import { z } from 'zod';

const options: ErrorMessageOptions = {
  delimiter: {
    error: ' ',
  },
  path: {
    enabled: true,
    type: 'objectNotation',
    transform: ({ label, value }) => `<${label}: ${value}>`,
  },
  code: {
    enabled: true,
    transform: ({ label, value }) => `<${label}: ${value}>`,
  },
  message: {
    enabled: true,
    transform: ({ label, value }) => `<${label}: ${value}>`,
  },
  transform: ({ errorMessage }) => `👉 ${errorMessage} 👈`,
};

const schema = z.object({
  animal: z.enum(['🐶', '🐱', '🐵']),
  quantity: z.number().gte(1),
});

const data = {
  animal: '🐼',
  quantity: 0,
};

try {
  const safeData = parse(schema, data, options);
  /**
   * Asynchronous version
   * const safeData = await parseAsync(schema, data, options);
   */
} catch (error) {
  /**
   * Replaces ZodError with a JavaScript
   * Error object with custom formatted message.
   */
  if (error instanceof Error) {
    console.error(error.message);
  }
}

Error Message:

👉 <Code: : invalid_enum_value> ~ <Path: : animal> ~ <Message: : Invalid enum value. Expected '🐶' | '🐱' | '🐵', received '🐼'> 👈 👉 <Code: : too_small> ~ <Path: : quantity> ~ <Message: : Number must be greater than or equal to 1> 👈

Note:

If your schema contains an async .refine() or .transform() function, use parseAsync() instead.

safeParse<T extends z.ZodTypeAny>(schema: T, data: unknown, options?: ErrorMessageOptions): SafeParseReturnType<T['_output']

Replaces Zod's .safeParse() function by replacing Zod's SafeParseReturnType with a similar return type where if result.success is false, the custom formatted error message will be available on result.error.message.

import { ErrorMessageOptions, safeParse } from 'zod-error';
import { z } from 'zod';

const options: ErrorMessageOptions = {
  prefix: `Time: ${new Date().toISOString()} ~ `,
  suffix: '🔚',
};

const schema = z.object({
  id: z.string().uuid(),
  timestamp: z.number(),
  message: z.string().min(5),
});

const data = {
  id: 'ID001',
  timestamp: new Date(),
  message: 'lol!',
};

const result = safeParse(schema, data, options);
/**
 * Asynchronous version
 * const result = await safeParseAsync(schema, data, options);
 */
if (!result.success) {
  /**
   * Replaces Zod's error object with custom
   * error object with formatted message.
   */
  const message = result.error.message;
  console.error(message);
} else {
  const safeData = result.data;
}

Error Message:

Time: 2022-07-14T11:10:10.602Z ~ Code: invalid_string ~ Path: id ~ Message: Invalid uuid | Code: invalid_type ~ Path: timestamp ~ Message: Expected number, received date | Code: too_small ~ Path: message ~ Message: String must contain at least 5 character(s)🔚

Note:

If your schema contains an async .refine() or .transform() function, use safeParseAsync() instead.

Authors

• @andrewvo89 - Idea & Initial work.

See also the list of contributors who participated in this project.

Acknowledgements

• Zod for an amazing validation library.