SwaggerHub shows API response as [null] instead of array

Question

I have an OpenAPI 3.0 definition in SwaggerHub at https://app.swaggerhub.com/apis/PHP-Point-Of-Sale/PHP-Point-Of-Sale/1.0#/customers/get_customers

The example response is [null] when I believe it should show example values based on how I setup the OpenAPI definition.

openapi: 3.0.0
...

paths:
  /customers:
    get:
      tags:
        - customers
      summary: Search/list customers
      description: ''
      parameters:
        - name: search
          in: query
          description: Search customers
          required: false
          schema:
            type: string
        - name: search_field
          in: query
          description: Search specific field
          required: false
          schema:
            type: string
            enum:
              - first_name
              - last_name
              - email
              - phone_number
              - account_number
              - custom_field_1
              - custom_field_2
              - custom_field_3
              - custom_field_4
              - custom_field_5
              - custom_field_6
              - custom_field_7
              - custom_field_8
              - custom_field_9
              - custom_field_10
        - name: offset
          in: query
          description: Offset to list customers
          required: false
          schema:
            type: integer
            minimum: 0
            default: 0
        - name: limit
          in: query
          description: Number of customers to get
          required: false
          schema:
            type: integer
            minimum: 1
            maximum: 100
            default: 20
      responses:
        '200':
          description: successful operation
          headers:
            x-total-records:
              description: Total number of results in search
              schema:
                type: integer
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Customers'
            application/xml:
              schema:
                $ref: '#/components/schemas/Customers'
        '400':
          description: Invalid parameter(s)


components:
  schemas:
    Customer:
      type: object
      allOf:
        - $ref: '#/components/schemas/ExistingPerson'
        - $ref: '#/components/schemas/NewCustomerWithImageUrl'

    Customers:
      type: array
      items:
        $ref: '#/components/schemas/Customer'

    ExistingPerson:
      type: object
      properties:
        person_id:
          type: integer
          format: uuid
          example: 3


    NewCustomerWithImageUrl:
      allOf:
        - $ref: '#/components/schemas/NewCustomer'
        - type: object
          properties:
            image_url:
              type: string
              example: http://www.abc.xyz

    NewCustomer:
      type: object
      allOf:
        - $ref: '#/components/schemas/Person'
        - type: object
          properties:
            company_name:
              type: string
              example: PHP Point Of Sale
            tier_id:
              type: integer
              format: uuid
              example: 0
            account_number:
              type: string
              example: '3333'
            taxable:
              type: boolean
              example: false
            tax_certificate:
              type: string
              example: '1234'
            override_default_tax:
              type: boolean
              example: false
            tax_class_id:
              type: integer
              format: uuid
              example: 0
            balance: 
              type: number
              format: float
              example: 22.99
            credit_limit:
              example: null
            points:
              type: integer
              format: int32
              example: 333
            disable_loyalty:
              type: boolean 
              example: true
            amount_to_spend_for_next_point:
              type: number
              format: float
              readOnly: true
              example: 10.00
            remaining_sales_before_discount:
              type: integer
              format: int32
              readOnly: true
              example: 0
          xml:  
            name: Customer

Answer 1

The issue seems to have been fixed and is no longer reproduced as of November 2018.

Original answer:

Your response example is displayed correctly in http://editor.swagger.io which (at the time of writing) uses Swagger UI 3.12.0.

It looks like SwaggerHub uses an older version of Swagger UI. You should contact SwaggerHub Support and ask them to update to the latest Swagger UI.