Zod Integration (in progress)

ds-express-errors automatically identifies Zod validation errors and maps them to 400 Bad Request.

The Zod mapper works out of the box and does not require Zod to be passed to ds-express-errors.

1. Basic integration
2. Supported errors
3. Configuration
4. Strict error detection
5. Example
6. Resulting responses

1. Basic Integration

Use Zod normally to validate data in your Express application and add the ds-express-errors error handler after all routes.

Add errorHandler after your application routes:

javascript

Import syntaxES Modules (import)CommonJS (require) Copy

import express from 'express'
import { errorHandler } from 'ds-express-errors'

const app = express();

// Your routes

// Add Error Handler at the very end
app.use(errorHandler);

2. Supported Errors

The Zod mapper handles validation errors containing a Zod issues array.

Each issue is converted into a message containing its path and validation message.

For example, Zod issues such as:

javascript

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[ 
  { 
    path: ['email'], 
    message: 'Invalid email address' 
  }, 
  { 
    path: ['profile', 'age'], 
    message: 'Too small: expected number to be >=18' 
  } 
]

are formatted as:

The resulting error is mapped to 400 Bad Request.

3. Configuration

By default, all available mappers are enabled.

If you want ds-express-errors to use only selected mappers, configure them with needMappers:

javascript

Import syntaxES Modules (import)CommonJS (require) Copy

import { setConfig } from 'ds-express-errors'

setConfig({ needMappers: ['zod'] })

4. Strict Error Detection

By default, ds-express-errors follows its zero dependency policy and identifies supported third-party errors without requiring Zod as its own dependency.

The default detection checks for an issues array with a validation path.

For strict detection, you can provide Zod through errorClasses:

javascript

Import syntaxES Modules (import)CommonJS (require) Copy

import { setConfig } from 'ds-express-errors'
import { z } from 'zod'

setConfig({ 
  errorClasses: {
    Zod: z
  } 
})

When Zod is provided, ds-express-errors uses:

err instanceof z.ZodError

to identify Zod errors.

5. Example

javascript

Import syntaxES Modules (import)CommonJS (require) Copy

import { z } from 'zod'
            
const userSchema = z.object({ 
  email: z.string().email(), 
  age: z.number().min(18) 
})

Invalid data can be passed to parse() normally:

javascript

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userSchema.parse({ 
  email: 'not-an-email', 
  age: 16 
})

Zod throws a validation error containing its validation issues.

You do not need to catch the error and manually convert every Zod issue into an HTTP error. Once it reaches errorHandler, the Zod mapper handles the conversion.

6. Resulting Responses

For a supported Zod error, the final response follows the standard ds-express-errors response format. (configured by setConfig())

json

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{ 
	"status": "fail", 
	"message": "[Validation error]: email: Invalid email address; age: Too small: expected number to be >=18" 
}