Schema property "implementation" prints the whole object instead of $ref in "/openapi"

[shankar6477]

Describe the bug
Adding the property "implementation" in Schema prints the whole object's structure instead of "$ref".

Example :
@Schema(name = "paymentInformation", type = SchemaType.ARRAY, minItems = 1, maxItems = 1, implementation = PaymentInstruction.class)
@NotNull
@SiZe(min=1, max=1)
private @Valid List paymentInformation = new ArrayList();

Steps to Reproduce
Add property "implementation" to an ArrayList of user defined class.
@Schema(name = "paymentInformation", type = SchemaType.ARRAY, minItems = 1, maxItems = 1, implementation = PaymentInstruction.class)
@NotNull
@SiZe(min=1, max=1)
private @Valid List paymentInformation = new ArrayList();

Expected behavior
Openapi should refer to the existing object using $ref instead of printing the whole object
This is the snippet without implementation class (using $ref)
@Schema(name = "payment_information", type = SchemaType.ARRAY, minItems = 1, maxItems = 1)
private @Valid List paymentInformation = new ArrayList<>();
payment_information:
maxItems: 1
minItems: 1
type: array
description: payment info
items:
type: array
description: payment info
items:
$ref: '#/components/schemas/PaymentInstruction'

This is post adding implementation class
@Schema(name = "payment_information", type = SchemaType.ARRAY, minItems = 1, maxItems = 1, implementation = PaymentInstruction.class)
private @Valid List paymentInformation = new ArrayList<>();
payment_information:
maxItems: 1
minItems: 1
type: array
description: payment info
items:
maxItems: 1
required:
- credit_transfer_transaction_information
- debtor
- debtor_account
- payment_information_identification
type: object
properties:
payment_information_identification:
maxLength: 35
minLength: 1
type: string
description: Unique identification, as assigned by a sending party,
to unambiguously identify the payment information group within
the message
example: 1047658536..............

Diagnostic information:

• OpenLiberty Version: 20.0.0.6
• Java Version: java version "1.8.0"
  Java(TM) SE Runtime Environment (build pwa6480sr2fp10ifix-20160223_01(SR2 FP10+IV81318+IV81645+IV81741+IV81716))
  IBM J9 VM (build 2.8, JRE 1.8.0 Windows 10 amd64-64 Compressed References 20160210_289934 (JIT enabled, AOT enabled)
  J9VM - R28_Java8_SR2_20160210_1617_B289934
  JIT - tr.r14.java_20151209_107110.04
  GC - R28_Java8_SR2_20160210_1617_B289934_CMPRSS
  J9CL - 20160210_289934)
  JCL - 20151231_01 based on Oracle jdk8u71-b15
• server.xml configuration

jsp-2.3 microProfile-3.0 jaxb-2.2

<!-- To access this server from a remote client add a host attribute to the following element, e.g. host="*" -->
<httpEndpoint id="defaultHttpEndpoint"
              httpPort="9080"
              httpsPort="9443" />
<!-- Automatically expand WAR files and EAR files -->
<applicationManager autoExpand="true"/>

- If it would be useful, upload the messages.log file found in `$WLP_OUTPUT_DIR/messages.log`

Additional context
Add any other context about the problem here.

[msmiths]

@shankar6477 This issue is working as designed. The schema will always be inlined (rather than using $ref) because it is not a simple usage of the implementation attribute on the @Schema annotation, i.e., the inclusion of other attributes (minItems and maxItems in this case) effectively means that a new schema is being defined.

However, this issue can be avoided when using the mpOpenAPI-2.0 feature by not including the implementation attribute on the @Schema annotation.

mpOpenAPI-2.0 is included as beta in the upcoming OpenLiberty 20.0.0.11 release.

Please see the following PR for details: #13589.

[tevans78]

Closing as working as designed, please re-open if you disagree.