erratum v3.0.0
Erratum
Erratum is an extension of the native Error class that adds support for additional properties, simple assertions and can be extended as any other ES6 class.
API
new Erratum()
new Erratum([data], message)
Arguments:
- data: optional additional data
- message: the error message
Quick example:
const Erratum = require('erratum');
const err = new Erratum({statusCode: 500}, 'The answer is: 42');
err instanceof Error // true
err instanceof Erratum // true
err.statusCode === 500 // true
err.message === 'This answer is: 42'; // true
Extending Erratum
Erratum
can be extended as any other ES6 class.
class ExtendedErratum extends Erratum {};
const err = new ExtendedErratum({statusCode: 500}, 'The answer is: 42');
err instanceof Error // true
err instanceof Erratum // true
err instanceof ExtendedErratum // true
err.statusCode === 500 // true
err.message === 'This answer is: 42'; // true
Default values
Classes extending Erratum
can specify default values to be set on their instances and optionally overridden through the data
argument.
class ExtendedErratum extends Erratum {
static get defaults() {
return {
...super.defaults,
hello: 'world',
statusCode: 500
}
}
};
const err = new ExtendedErratum({statusCode: 400}, 'The answer is: 42');
err.hello === 'world' // true
err.statusCode === 500 // false
err.statusCode === 400 // true
Error wrapping
If data
is an instance of Error
or has either the err
property or the error
property set to an instance of Error
, the stack of the new Erratum
instance will incorporate the stack of the provided error. The latter will be available through the wrappedError
property.
const err = new Error('Something went wrong.');
throw new Erratum({err}, 'Yes, something definitely went wrong.');
Erratum: Yes, something definitely went wrong.
at repl:1:7
at REPLServer.defaultEval (repl.js:262:27)
at bound (domain.js:287:14)
at REPLServer.runBound [as eval] (domain.js:300:12)
at REPLServer.<anonymous> (repl.js:431:12)
at emitOne (events.js:82:20)
at REPLServer.emit (events.js:169:7)
at REPLServer.Interface._onLine (readline.js:211:10)
at REPLServer.Interface._line (readline.js:550:8)
at REPLServer.Interface._ttyWrite (readline.js:827:14)
Caused By: Error: Something went wrong.
at repl:1:17
at REPLServer.defaultEval (repl.js:262:27)
at bound (domain.js:287:14)
at REPLServer.runBound [as eval] (domain.js:300:12)
at REPLServer.<anonymous> (repl.js:431:12)
at emitOne (events.js:82:20)
at REPLServer.emit (events.js:169:7)
at REPLServer.Interface._onLine (readline.js:211:10)
at REPLServer.Interface._line (readline.js:550:8)
at REPLServer.Interface._ttyWrite (readline.js:827:14)
Assertions
Erratum
and all of its child classes support simple assertions through Erratum.assert()
.
Erratum.assert(check(), {statusCode: 500}, 'The answer is: 42');
Breaking changes
- 2.x.x
- Partial rewrite to update the code to ES6
- Dropped message formatting in favour of ES6' templates
- Dropped
Erratum.extend()
in favour of ES6' classes - Dropped using the constructor as a factory function (i.e. instantiating without
new
)
- 1.x.x
- Complete rewrite, extends the native
Error
class to better support error specialization Dropped
Erratum.wrap()
- Complete rewrite, extends the native
Test
$ npm test
License
See LICENSE.