jproulx / node-custom-error Goto Github PK

In the README.md, there is an example that says:

var ValidationError = createCustomError('ValidationError', { 'required', 'Missing parameter x' }, TypeError);

What is the second parameter?

To me, { 'required', 'Missing parameter x' } doesn't look like valid JavaScript syntax, but further below you write something about object descriptors. When I google for that, I only find information on enumerables, …

Can you explain whether this is a syntax error, or what kind of language construct this is?

This would be very helpful :-)

The custom constructor is called before the message is saved from the arguments, so any message set in the constructor is overwritten.

I want to create an error with custom constructor so I can set custom properties like this:

var HTTPError = createCustomError('HTTPError', null, function(code) {
  this.code = code;
});

var error = new HTTPError("You don't have permission', 403);

console.log(error.code);

I also want to wrap this error like this:

var error = new ValidationError("Missing field");
var serverError = new HTTPError("Something went wrong", error);

I can't do both at the same time, either I have to use a custom constructor, or another error object.
How can I create a custom error that wraps an error object, and I can set custom properties on it?