[BUG] x-pattern-message ignored for list items in Spring generator

[mkurczuk]

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• Have you tested with the latest master to confirm the issue still exists?
• Have you searched for related issues/PRs?
• What's the actual output vs expected output?
• [Optional] Sponsorship to speed up the bug fix or feature request (example)

Description

When generating code with the Spring generator using OpenAPI Generator (7.13.0), the x-pattern-message extension works correctly for single strings, but does not work for list items.

openapi-generator version

7.13.0

OpenAPI declaration file content or url

openapi: 3.0.3
info:
  title: Sample API
  version: 1.0.0
paths:
  /api/v1/endpoint:
    post:
      requestBody:
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/SomeRequest'
      responses:
        '204':
          description: Success
components:
  schemas:
    SomeRequest:
      type: object
      description: Request
      properties:
        patternList:
          description: List of patterns
          type: array
          items:
            type: string
            pattern: '^[\w\W]*$'
            x-pattern-message: Custom message for list
        patternString:
            type: string
            description: Pattern string
            pattern: '^[\w\W]*$'
            x-pattern-message: Custom message for string

Generation Details

openapi-generator-cli generate -g spring -c api-config.json -i test-api.yaml

api-config.json:

{
  "interfaceOnly": true,
  "apiTests": false,
  "modelTests": false,
  "hideGenerationTimestamp": true,
  "useSpringBoot3": true,
  "useJakartaEe": true,
  "useTags": true,
  "useEnumCaseInsensitive": true
}

Steps to reproduce

The generated model class should assign the custom message for both patternString and each item in patternList.

Actual Behavior:

• For patternString, the custom message is correctly applied:

  private @Nullable String patternString;

  @Pattern(regexp = "^[\\w\\W]*$", message="Custom message for string") 
  @Schema(name = "patternString", description = "Pattern string", requiredMode = Schema.RequiredMode.NOT_REQUIRED)
  @JsonProperty("patternString")
  public String getPatternString() {
    return patternString;
  }

• For patternList, the custom message is missing:

  @Valid
  private List<@Pattern(regexp = "^[\\w\\W]*$") String> patternList;

  @Schema(name = "patternList", description = "List of patterns", requiredMode = Schema.RequiredMode.NOT_REQUIRED)
  @JsonProperty("patternList")
  public List<@Pattern(regexp = "^[\\w\\W]*$")String> getPatternList() {
    return patternList;
  }

Related issues/PRs

Suggest a fix

It would be ideal if the generated annotation for list items was like:

  @Valid
  private List<@Pattern(regexp = "^[\\w\\W]*$", message="Custom message for list") String> patternList;
 
  @Schema(name = "patternList", description = "List of patterns", requiredMode = Schema.RequiredMode.NOT_REQUIRED)
  @JsonProperty("patternList")
  public List<@Pattern(regexp = "^[\\w\\W]*$", message="Custom message for list")String> getPatternList() {
    return patternList;
  }

instead of omitting the message part.