ehmicky
Properly update an error's properties.
Features
- Prevents overriding error core properties (
name,message, etc.) - Protects against prototype pollution
- Prevents overriding existing properties
- Copies another error's properties
- Can set properties as non-enumerable
- Preserves properties descriptors (
enumerable,writable,configurable,get/set) - Exception-safe: this only throws syntax errors
- Strict TypeScript typing of the return value
Example
import setErrorProps from 'set-error-props'
const error = new Error('one')
setErrorProps(error, { prop: true, message: 'two' })
console.log(error.prop) // true
console.log(error.message) // 'one': message is readonlyInstall
npm install set-error-propsThis package works in both Node.js >=18.18.0 and browsers.
This is an ES module. It must be loaded using
an import or import() statement,
not require(). If TypeScript is used, it must be configured to
output ES modules,
not CommonJS.
API
setErrorProps(error, props, options?)
error Error | object\
props Error | object\
options Options?\
Return value: Error
Assigns props to error, then returns error.
Options
soft
Type: boolean\
Default: false
Prevents overriding existing properties.
Usage
Error core properties
const error = new Error('one')
setErrorProps(error, { message: 'two' })
console.log(error.message) // 'one'Prototype pollution
const error = new Error('one')
setErrorProps(error, { toString: () => 'injected' })
console.log(error.toString()) // 'Error: one'
console.log(Error.prototype.toString()) // 'Error'Overriding protection
const error = new Error('message')
error.one = true
setErrorProps(error, { one: false, two: true }, { soft: true })
console.log(error.one) // true
console.log(error.two) // trueError copy
const error = new Error('one')
const secondError = new Error('two')
secondError.prop = true
setErrorProps(error, secondError)
console.log(error.message) // 'one'
console.log(error.prop) // trueNon-enumerable properties
const error = new Error('message')
// Properties that start with `_` are not enumerable
setErrorProps(error, { _one: true, two: true })
console.log(error._one) // true
console.log(error.two) // true
console.log(Object.keys(error)) // ['two']
console.log(error) // Prints `two` but not `_one`Descriptors
const error = new Error('message')
Object.defineProperty(error, 'prop', {
value: false,
enumerable: false,
writable: true,
configurable: true,
})
setErrorProps(error, { prop: true })
console.log(error.prop) // true
console.log(Object.getOwnPropertyDescriptor(error, 'prop').enumerable) // falseException safety
const error = new Proxy(new Error('message'), {
set: () => {
throw new Error('example')
},
defineProperty: () => {
throw new Error('example')
},
})
setErrorProps(error, { prop: true }) // This does not throwRelated projects
modern-errors: Handle errors in a simple, stable, consistent wayerror-custom-class: Create one error classerror-class-utils: Utilities to properly create error classeserror-serializer: Convert errors to/from plain objectsnormalize-exception: Normalize exceptions/errorsis-error-instance: Check if a value is anErrorinstanceset-error-class: Properly update an error's classset-error-message: Properly update an error's messagewrap-error-message: Properly wrap an error's messageset-error-stack: Properly update an error's stackmerge-error-cause: Merge an error with itscauseerror-cause-polyfill: Polyfillerror.causehandle-cli-error: 💣 Error handler for CLI applications 💥log-process-errors: Show some ❤ to Node.js process errorserror-http-response: Create HTTP error responseswinston-error-format: Log errors with Winston
Support
For any question, don't hesitate to submit an issue on GitHub.
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Contributing
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