Normalize exceptions/errors
npm install normalize-exception






Normalize:
- Exceptions that are not Error instances
- Error properties (name, message, stack, constructor) that are
missing, invalid,
enumerable, readonly,
non-writable,
non-configurable,
non-extensible, proxied or
throwing
- error.cause
and
error.errors
recursively, when present
``js
import normalizeException from 'normalize-exception'
try {
throw 'message'
} catch (error) {
console.log(error) // 'message'
console.log(normalizeException(error)) // Error: message
console.log(normalizeException(error) instanceof Error) // true
}
`
`bash`
npm install normalize-exception
This 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.
error any\options Options\Error
_Return value_:
normalizeException() never throws.
If error is an Error instance, it is returned. Any missing or invalid error
property is directly modified.
If it is not an Error instance, a new one is created and returned.
Options are an optional object with the following properties.
#### shallow
_Type_: boolean\false
_Default_:
Unless true,error.causeerror.errors
and
are normalized recursively, when present.
`js`
try {
throw 'message'
} catch (error) {
console.log(error) // 'message'
console.log(normalizeException(error)) // Error: message
console.log(normalizeException(error) instanceof Error) // true
}
`js`
try {
throw { name: 'TypeError', message: 'message' }
} catch (error) {
console.log(normalizeException(error)) // TypeError: message
}
`js`
try {
throw null
} catch (error) {
console.log(error.message) // Throws
console.log(normalizeException(error).message) // 'null'
}
`js`
try {
const error = new TypeError('message')
error.name = undefined
throw error
} catch (error) {
console.log(error.name) // undefined
console.log(normalizeException(error).name) // 'TypeError'
}
`js`
try {
const error = new TypeError('message')
error.constructor = RangeError
throw error
} catch (error) {
console.log(error.constructor) // RangeError
console.log(normalizeException(error).constructor) // TypeError
}
`js`
try {
const error = new Error('message')
error.stack = undefined
throw error
} catch (error) {
console.log(error.stack) // undefined
console.log(normalizeException(error).stack) // 'Error: message ...'
}
`js`
try {
const error = new Error('message')
error.message = true
throw error
} catch (error) {
console.log(typeof error.message) // 'boolean'
console.log(typeof normalizeException(error).message) // 'string'
}
`jserror.name
class ExampleError extends Error {
constructor(...args) {
super(...args)
// Common mistake: this makes enumerable
this.name = 'ExampleError'
}
}
try {
throw new ExampleError('message')
} catch (error) {
console.log({ ...error }) // { name: 'ExampleError' }
console.log({ ...normalizeException(error) }) // {}
}
`
`js`
try {
const error = new Error('message')
Object.defineProperty(error, 'message', { get: () => 'message' })
throw error
} catch (error) {
error.message = 'other' // Throws
normalizeException(error).message = 'other' // Does not throw
}
`js`
try {
const error = new Error('message')
Object.defineProperty(error, 'message', { value: '', writable: false })
throw error
} catch (error) {
error.message = 'other' // Throws
normalizeException(error).message = 'other' // Does not throw
}
`js`
try {
const error = new Error('message')
Object.defineProperty(error, 'message', { value: '', configurable: false })
throw error
} catch (error) {
delete error.message // Throws
delete normalizeException(error).message // Does not throw
}
`js`
try {
const error = new Error('message')
Object.preventExtensions(error)
throw error
} catch (error) {
error.prop = true // Throws
normalizeException(error).prop = true // Does not throw
}
`js`
try {
throw new Proxy(new Error('message'), {})
} catch (error) {
const { toString } = Object.prototype
console.log(toString.call(error)) // '[object Object]'
console.log(toString.call(normalizeException(error))) // '[object Error]'
}
`js`
try {
throw new Proxy(new Error('message'), {
get: () => {
throw new Error('example')
},
})
} catch (error) {
console.log(error.message) // Throws
console.log(normalizeException(error).message) // Does not throw
}
`js`
try {
const error = new Error('message')
Object.defineProperty(error, 'message', {
get: () => {
throw new Error('example')
},
})
throw error
} catch (error) {
console.log(error.message) // Throws
console.log(normalizeException(error).message) // Does not throw
}
`js`
try {
throw new Error('message', { cause: 'innerError' })
} catch (error) {
console.log(error.cause instanceof Error) // false
console.log(normalizeException(error).cause instanceof Error) // true
}
`js`
try {
throw new AggregateError(['innerError'], 'message')
} catch (error) {
console.log(error.errors[0] instanceof Error) // false
console.log(normalizeException(error).errors[0] instanceof Error) // true
}
- modern-errors: Handle errors in
a simple, stable, consistent way
- error-custom-class: Create
one error class
- error-class-utils: Utilities
to properly create error classes
- error-serializer: Convert
errors to/from plain objects
- merge-error-cause: Merge an
error with its causeis-error-instance
- : Check ifError
a value is an instanceset-error-class
- : Properlyset-error-message
update an error's class
- : Properlywrap-error-message
update an error's message
- :set-error-props
Properly wrap an error's message
- : Properlyset-error-stack
update an error's properties
- : Properlyerror-cause-polyfill
update an error's stack
- :error.cause
Polyfill handle-cli-error
- : 💣 Errorlog-process-errors
handler for CLI applications 💥
- : Showerror-http-response
some ❤ to Node.js process errors
- :winston-error-format
Create HTTP error responses
- : Log
errors with Winston
For any question, _don't hesitate_ to submit an issue on GitHub.
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