Add support for multple errors returned

[wesbos]

thanks for the lib!

Looks like canada post will return an array of errors if multiple things are wrong. Currently it just swallows that error.

[t3rminus]

Oh! Absolutely a good idea. Can you give me an example of a request with multiple errors, so I can add a test case for this, and make sure everything works as expected?

Then I can merge your PR.

[wesbos]

Great! This should cause the following errors:

{
  '$': { xmlns: 'http://www.canadapost.ca/ws/messages' },
  message: [
    {
      code: '2695',
      description: 'Contact Phone number is a required field.'
    },
    {
      code: '1151',
      description: 'At least one line of Customs Description must be supplied.'
    },
    {
      code: '8716',
      description: 'This product requires a valid value for Non-Delivery Handling.'
    }
  ]
}

const shipment4 = {
  requestedShippingPoint: 'M4X1P1',
  deliverySpec: {
    serviceCode: 'USA.XP',
    sender: {
      company: 'Wes Bos',
      contactPhone: '911',
      addressDetails: {
        addressLine1: '123 fake street',
        city: 'Fake',
        provState: 'ON',
        postalZipCode: 'M4X1P1'
      }
    },
    destination: {
      name: 'Larry David',
      addressDetails: {
        addressLine1: "123 Fake street",
        city: 'Denver',
        provState: 'CO',
        postalZipCode: '90210',
        countryCode: 'US'
      }
    },
    parcelCharacteristics: {
      weight: 1,
      document: false,
      dimensions: {
        length: 23,
        width: 18,
        height: 10
      }
    },
    preferences: {
      showPackingInstructions: true,
      showPostageRate: false,
      showInsuredValue: false
    },
    references: {
      customerRef1: 'test'
    },
  }
};

async function createShipment() {
  const res = await client.createNonContractShipment(shipment4);

  console.log(res);
}

createShipment().catch(console.error);

[t3rminus]

I moved some error parsing code into the CanadaPostError constructor. I also included the original messages in the error, to make parsing/iterating over them easier.

error.code is never an array (it now concatenates codes with ,), but you can use error.originalMessages to loop over them if you need individual codes.

Pushed to NPM as v1.2.0