Swagger: how to represent a property whose type is oneOf a list of types? - swagger

Question

I have an object that has a property that is an object whose type would be one of list of types. All my attempts have been rejected by Swagger Editor with the following error:
Data does not match any schemas from 'anyOf'
Jump to line 43
Details
Object
code: "ANY_OF_MISSING"
message: "Data does not match any schemas from 'anyOf'"
path: Array [7]
inner: Array [2]
level: 900
type: "Swagger Error"
description: "Data does not match any schemas from 'anyOf'"
lineNumber: 43
The full swagger specification file is as follows (the field in question is DataSetsInquiryRsp.dataSets.dataSet):
swagger: '2.0'
info:
title: My API
description: My Awesome API
version: 1.0.0
paths:
/dataSetsInquiry:
get:
description: Retrieve one or more data-sets.
parameters:
- name: ids
in: query
description: List of identifiers of requested data-sets.
required: true
type: array
items:
type: string
responses:
'200':
description: Requested data-sets.
schema:
$ref: '#/definitions/DataSetsInquiryRsp'
default:
description: Unexpected error
schema:
$ref: '#/definitions/Error'
definitions:
DataSetsInquiryRsp:
type: object
additionalProperties: false
properties:
sessionIdentifier:
description: Identifier of the secure session with the server.
type: number
dataSets:
type: object
additionalProperties: false
properties:
id:
type: string
dataSet:
type: array
items:
oneOf:
- $ref: '#/definitions/Customer'
- $ref: '#/definitions/Merchant'
Customer:
type: object
additionalProperties: false
properties:
firstName:
description: First name of the customer
type: string
lastName:
description: Last name of the customer
type: string
Merchant:
type: object
additionalProperties: false
properties:
code:
description: Code the Merchant.
type: string
name:
description: Name of the Merchant.
type: string

Answer 1

Well, the issue is simply the fact that Swagger doesn't support oneOff. In fact, Swagger supports a subset of Json-Schema and add a few things (datatype file for instance).
What is bad here is the error returned by Swagger. It doesn't help match. And this is the case of all Json-Schema validators I have worked with so far: is-my-json-valid, jsen.