[BUG][JAVA] @Size not generated when request body is a list of primitive type elements

[k0sr]

Description

I'm trying to generate some javax.validation annotations in my generated Spring API files. Most of the cases are working fine, but when I try to add a size validation on a request body which is a list of primitive type elements, by adding minItems or maxItems for example, the generated method does not contain the expected javax.validation @Size annotation. Plus, I would also like to validate the length of each element inside my list

Actual:

ResponseEntity<Void> syncCars(@ApiParam(value = ""  )
                              @Valid
                              @RequestBody List<String> requestBody);

Expected:

ResponseEntity<Void> syncCars(@Size(min=1,max=100)
                              @ApiParam(value = ""  )
                              @Valid
                              @RequestBody List<@Size(min=5,max=100) String> requestBody);

or at least

ResponseEntity<Void> syncCars(@Size(min=1,max=100)
                              @ApiParam(value = ""  )
                              @Valid
                              @RequestBody List<String> requestBody);

When I try this by manually modifying the generated interface, the validation works great and throw errors when I send an empty list or a list with string which is too short.
Additionally, I would like to know if OAS uniqueItems property could, or should, generate anything else?

openapi-generator version

3.3.4 (maven plugin). I also tried the latest version, the result is the same

OpenAPI declaration file content or url

openapi: 3.0.0
servers:
  - url: 'http://localhost:8080/'
info:
  version: '1.0'
  title: My Project
paths:
  /cars/sync:
    post:
      tags:
        - Cars
      summary: test
      operationId: syncCars
      requestBody:
        content:
          application/json:
            schema:
              type: array
              items:
                type: string
                minLength: 5
                maxLength: 100
              minItems: 1
              maxItems: 100
              uniqueItems: true
      responses:
        '200':
          description: success

Command line used for generation

<plugin>
  <groupId>org.openapitools</groupId>
  <artifactId>openapi-generator-maven-plugin</artifactId>
  <version>3.3.4</version>
  <executions>
    <execution>
      <goals>
        <goal>generate</goal>
      </goals>
      <configuration>
        <inputSpec>${project.basedir}/src/main/resources/api.yaml</inputSpec>
        <generatorName>spring</generatorName>
        <output>target/generated-sources</output>

        <modelNameSuffix>Dto</modelNameSuffix>
        <generateSupportingFiles>false</generateSupportingFiles>
        <apiPackage>my.api</apiPackage>
        <modelPackage>my.api.dto</modelPackage>

        <configOptions>
          <sourceFolder>src/main/java/</sourceFolder>
          <java8>false</java8>
          <interfaceOnly>true</interfaceOnly>
          <dateLibrary>java8-localdatetime</dateLibrary>
        </configOptions>

      </configuration>
    </execution>
  </executions>
</plugin>

[baurceanu]

imho, uniqueItems: true should generate Set instead of List
UPD or add org.hibernate.validator.constraints.UniqueElements (javax.validation.validation-api doesn't have an appropriate one). It migth be an option to add a new config option for specifying the strategy.

[k0sr]

Does anyone have any explanations about @Size issue on a request body containing only a list of String?

[PrateekSB]

Hi,

This is not working for me too but not with primitive lists, for me, it's not working with a list of objects.

Regards,
Prateek

[FinKingma]

For us the minLength and maxLength within a query parameter value was working up until openapi-generator-gradle-plugin version 5.3.0. It broke when we switched to 5.4.0

5.2.0 generates:
... Optional<@Size(min=0,max=150) List<String>> listOfItems

5.4.0 generates:
... Optional<List<String>> listOfItems

reproduced with the following yaml:

info:
  title: Test API
  version: '@api.version@'
  description: API te reproduce an issue with generating size annotations as of 5.4.0
paths:
  /pets/{listOfItems}/info:
    get:
      operationId: useList
      summary: use a list
      parameters:
        - $ref: '#/components/parameters/listOfItems'
      responses:
        200:
          description: Succes respons
          content:
            application/json:
              schema:
                type: string
components:
  parameters:
    listOfItems:
      name: listOfItems
      in: query
      required: false
      schema:
        type: array
        minLength: 0
        maxLength: 150
        items:
          type: string
          minLength: 1
          maxLength: 7```

[sburkard]

As @PrateekSB already stated, this is not limited to arrays of primitive types.

I have the same issue with an array of objects:

      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: array
              items:
                $ref: '#/components/schemas/MyRequestObject'
              # Currently not working due to a bug (https://github.com/OpenAPITools/openapi-generator/issues/4122)
              maxItems: 1000