@kernel/exceptions

Common error classes

• Suite of node.js Error classes like most other modern languages

• Generate your own custom Error classes

• Map HTTP status codes to Errors for automatic handling responses from web services and applications

• Suitable to run on browsers (client-side)

Install

npm install @kernel/exceptions

Class Directory

Common Error Classes

• AlreadyInUseError

• ArgumentError

• ArgumentNullError

• AuthenticationRequiredError

• ConnectionError

• DataError

• ForbiddenError

• HttpError

• InvalidOperationError

• SocketError

• NotFoundError

• NotImplementedError

• NotPermittedError

• NotSupportedError

• RangeError

• ReferenceError

• SyntaxError

• TimeoutError

• TypeError

• URIError

Error Classes

AlreadyInUseError

Applicable when a resource is already in use, for example unique key constraints like a username.

new AlreadyInUseError(entityName, [arg1, arg2, arg3, ..., error])

Arguments

• entityName - the entity that owns the protected resource

• args - the fields or attributes that are already in use

• error - the Error instance that caused the current error. Stack trace will be appended

// Example
throw new AlreadyInUseError('user', 'username');

ArgumentError

Applicable when there's a generic problem with an argument received by a function call.

new ArgumentError(argumentName[, error])

Arguments

• argumentName - the name of the argument that has a problem

• error - the Error instance that caused the current error. Stack trace will be appended

// Example
throw new ArgumentError('username', 500, err);

ArgumentNullError

Applicable when an argument received by a function call is null/undefined or empty.

new ArgumentNullError(message[, code, error])

Arguments

• message - any message

• code - the error code

• error - the Error instance that caused the current error. Stack trace will be appended

// Example
throw new ArgumentNullError('username', 400, err);

AuthenticationRequiredError

Applicable when an operation requires authentication

new AuthenticationRequiredError(message, [code, error])

Arguments

• message - any message

• code - the error code

• error - the Error instance that caused the current error. Stack trace will be appended

// Example
throw new AuthenticationRequiredError("Please provide authentication.", 403, err);

ConnectionError

Applicable when an error occurs on a connection.

new ConnectionError(message[, code, error])

Arguments

• message - any message

• code - the error code

• error - the Error instance that caused the current error. Stack trace will be appended

// Example
throw new ConnectionError('WebService unavailable');
throw new ConnectionError('Database connection no longer available', 500, err);

DataError

Applicable when an error occurs on or with an external data source.

new DataError(message[, code, error])

Arguments

• message - any message

• code - the error code

• error - the Error instance that caused the current error. Stack trace will be appended

// Example
throw new DataError('Too many rows returned from database', 500, err);

ForbiddenError

Applicable when an operation is not permitted

new ForbiddenError(message[, code, error])

Arguments

• message - any message

• code - the error code

• error - the Error instance that caused the current error. Stack trace will be appended

// Example
throw new NotPermittedError("username cannot be changed once set.", 403, err);

HttpError

Represents a message and a HTTP status code.

new HttpError(code[, message, codeMap, error])

Arguments

• code - any HTTP status code integer

• message - any message

• codeMap - the mapping of error codes and their classes

• error - the Error instance that caused the current error. Stack trace will be appended

// Default example
throw new HttpError(404);

// Example with error
throw new HttpError(404, err);

// Example with message and error
throw new HttpError(404, "Not Found", err);

// Example with custom codeMap and error
throw new HttpError(404, {
  400: 'ArgumentError',
  401: 'AuthenticationRequiredError',
  403: 'ForbiddenError',
  404: 'NotFoundError',
  405: 'NotSupportedError',
  409: 'AlreadyInUseError',
}, err);

InvalidOperationError

Applicable when an invalid operation occurs.

new InvalidOperationError(message[, code, error])

Arguments

• message - any message

• code - the error code

• error - the Error instance that caused the current error. Stack trace will be appended

// Example
throw new InvalidOperationError('Divide by zero', 500, err);

NotFoundError

Applicable when an attempt to retrieve data yielded no result.

new NotFoundError(entity_name[, code, error])

Arguments

• entity_name - a description for what was not found

• code - the error code

• error - the Error instance that caused the current error. Stack trace will be appended

// Example
throw new NotFoundError("User", 500, err);

NotImplementedError

Applicable when a requested method or operation is not implemented.

new NotImplementedError(message[, code, error])

Arguments

• message - any message

• code - the error code

• error - the Error instance that caused the current error. Stack trace will be appended

// Example
throw new NotImplementedError("Method is not yet implemented.", 500, err);

NotSupportedError

Applicable when a certain condition is not supported by your application.

new NotSupportedError(message[, code, error])

Arguments

• message - a message

• code - the error code

• error - the Error instance that caused the current error. Stack trace will be appended

// Example
throw new NotSupportedError('Zero values', 500, err);

RangeError

Represents an error that occurs when a numeric variable or parameter is outside of its valid range. This is roughly the same as the native RangeError class. It additionally supports an code attribute.

new RangeError(message[, code, error])

Arguments

• message - a message

• code - the error code

• error - the Error instance that caused the current error. Stack trace will be appended

// Example
throw new RangeError("Value must be between " + MIN + " and " + MAX, err);

ReferenceError

Represents an error when a non-existent variable is referenced. This is roughly the same as the native ReferenceError class. It additionally supports an code attribute.

new ReferenceError(message[, code, error])

Arguments

• message - a message

• code - the error code

• error - the Error instance that caused the current error. Stack trace will be appended

// Example
throw new ReferenceError("x is not defined", 500, err);

SocketError

Applicable when an error occurs on a socket.

new SocketError(message[, code, error])

Arguments

• message - any message

• code - the error code

• error - the Error instance that caused the current error. Stack trace will be appended

// Example
throw new SocketError('Socket no longer available', 500, err);

SyntaxError

Represents an error when trying to interpret syntactically invalid code. This is roughly the same as the native SyntaxError class. It additionally supports an code attribute.

new SyntaxError(message[, code, error])

Arguments

• message - a message

• code - the error code

• error - the Error instance that caused the current error. Stack trace will be appended

// Example
throw new SyntaxError("Unexpected token a", 500, err);

TimeoutError

Applicable when an operation takes longer than the alloted amount.

new TimeoutError(time[, code, error])

Arguments

• time - a time duration

• code - the error code

• error - the Error instance that caused the current error. Stack trace will be appended

// Example
throw new TimeoutError('100ms', 500, err);

TypeError

Represents an error when a value is not of the expected type. This is roughly the same as the native TypeError class. It additionally supports an code attribute.

new TypeError(message[, code, error])

Arguments

• message - a message

• code - the error code

• error - the Error instance that caused the current error. Stack trace will be appended

// Example
throw new TypeError("number is not a function", 500, err);

URIError

Represents an error when a value is not of the expected type. This is roughly the same as the native URIError class. It additionally supports an code attribute.

new URIError(message[, code, error])

Arguments

• message - a message

• code - the error code

• error - the Error instance that caused the current error. Stack trace will be appended

// Example
throw new URIError("URI malformed", 500, err);