Zod Error

---

Utilities to format and customize Zod error messages.

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:

1[
2  {
3    code: 'invalid_type',
4    expected: 'string',
5    received: 'undefined',
6    path: ['name'],
7    message: 'Required',
8  },
9  {
10    code: 'invalid_type',
11    expected: 'string',
12    received: 'number',
13    path: ['pets', 1],
14    message: 'Expected string, received number',
15  },
16];

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.

1import { generateErrorMessage, ErrorMessageOptions } from 'zod-error';
2import { z } from 'zod';
3
4enum Color {
5  Red = 'Red',
6  Blue = 'Blue',
7}
8
9const options: ErrorMessageOptions = {
10  delimiter: {
11    error: ' 🔥 ',
12  },
13  transform: ({ errorMessage, index }) => `Error #${index + 1}: ${errorMessage}`,
14};
15
16const schema = z.object({
17  color: z.nativeEnum(Color),
18  shape: z.string(),
19  size: z.number().gt(0),
20});
21
22const data = {
23  color: 'Green',
24  size: -1,
25};
26
27const result = schema.safeParse(data);
28if (!result.success) {
29  const errorMessage = generateErrorMessage(result.error.issues, options);
30  throw new Error(errorMessage);
31}

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.

1import { ErrorMessageOptions, generateError } from 'zod-error';
2import { z } from 'zod';
3
4const options: ErrorMessageOptions = {
5  maxErrors: 2,
6  delimiter: {
7    component: ' - ',
8  },
9  path: {
10    enabled: true,
11    type: 'zodPathArray',
12    label: 'Zod Path: ',
13  },
14  code: {
15    enabled: false,
16  },
17  message: {
18    enabled: true,
19    label: '',
20  },
21};
22
23const schema = z.object({
24  dates: z.object({
25    purchased: z.date(),
26    fulfilled: z.date(),
27  }),
28  item: z.string(),
29  price: z.number(),
30});
31
32const data = {
33  dates: { purchased: 'yesterday' },
34  item: 1,
35  price: '1,000',
36};
37
38try {
39  schema.parse(data);
40} catch (error) {
41  const genericError = generateError(error, options);
42  throw genericError;
43}

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.

1import { ErrorMessageOptions, parse } from 'zod-error';
2import { z } from 'zod';
3
4const options: ErrorMessageOptions = {
5  delimiter: {
6    error: ' ',
7  },
8  path: {
9    enabled: true,
10    type: 'objectNotation',
11    transform: ({ label, value }) => `<${label}: ${value}>`,
12  },
13  code: {
14    enabled: true,
15    transform: ({ label, value }) => `<${label}: ${value}>`,
16  },
17  message: {
18    enabled: true,
19    transform: ({ label, value }) => `<${label}: ${value}>`,
20  },
21  transform: ({ errorMessage }) => `👉 ${errorMessage} 👈`,
22};
23
24const schema = z.object({
25  animal: z.enum(['🐶', '🐱', '🐵']),
26  quantity: z.number().gte(1),
27});
28
29const data = {
30  animal: '🐼',
31  quantity: 0,
32};
33
34try {
35  const safeData = parse(schema, data, options);
36  /**
37   * Asynchronous version
38   * const safeData = await parseAsync(schema, data, options);
39   */
40} catch (error) {
41  /**
42   * Replaces ZodError with a JavaScript
43   * Error object with custom formatted message.
44   */
45  if (error instanceof Error) {
46    console.error(error.message);
47  }
48}

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.

1import { ErrorMessageOptions, safeParse } from 'zod-error';
2import { z } from 'zod';
3
4const options: ErrorMessageOptions = {
5  prefix: `Time: ${new Date().toISOString()} ~ `,
6  suffix: '🔚',
7};
8
9const schema = z.object({
10  id: z.string().uuid(),
11  timestamp: z.number(),
12  message: z.string().min(5),
13});
14
15const data = {
16  id: 'ID001',
17  timestamp: new Date(),
18  message: 'lol!',
19};
20
21const result = safeParse(schema, data, options);
22/**
23 * Asynchronous version
24 * const result = await safeParseAsync(schema, data, options);
25 */
26if (!result.success) {
27  /**
28   * Replaces Zod's error object with custom
29   * error object with formatted message.
30   */
31  const message = result.error.message;
32  console.error(message);
33} else {
34  const safeData = result.data;
35}

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.