OpenApiInteractionValidator cannot be reused (stateful?)

[Christophe Schmaltz]

I try to validate the schema with com.atlassian.oai:swagger-request-validator-core:2.27.1 and com.atlassian.oai:swagger-request-validator-mockmvc:2.27.1 . Here is an excerpt of the test code (written in kotlin):

        val result = mockMvc.perform(get(url))
            .andExpect(status().is2xxSuccessful)
            .andExpect(isSwaggerValid())  // <= place where it breaks
            .andReturn()

I have written 3 different versions of the isSwaggerValid() -Method:

‌

    companion object { // These kotlin variables are like static fields in Java => common instances to all the tests
        val validatorBuilder = OpenApiInteractionValidator.createForInlineApiSpecification(SwaggerSchema.publicApi)
        val openApiInteractionValidator= validatorBuilder.build()
        val resultMatcher = OpenApiValidationMatchers.openApi().isValid(openApiInteractionValidator)
    }

    fun isSwaggerValid_OK(): ResultMatcher {
        // if I only reuse the validatorBuilder, everything works as expected
        return OpenApiValidationMatchers.openApi().isValid(validatorBuilder.build())
    }

    fun isSwaggerValid_Failing(): ResultMatcher {
        // This fails => openApiInteractionValidator is not stateless and breaks
        return OpenApiValidationMatchers.openApi().isValid(openApiInteractionValidator)
    }

    fun isSwaggerValid_Failing2(): ResultMatcher {
        // This also fails, which confirms the issue is with the openApiInteractionValidator
        return resultMatcher
    }

Only the first version (isSwaggerValid_OK) works when it is called multiple times. The other implementations fail on some tests.

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Exception message:

com.atlassian.oai.validator.mockmvc.OpenApiMatchers$OpenApiValidationException: {
  "messages" : [ {
    "key" : "validation.response.body.schema.type",
    "level" : "ERROR",
    "message" : "[Path '/alerts/0'] Instance type (string) does not match any allowed primitive type (allowed: [\"object\"])",
    "context" : {
      "requestPath" : "/accounts/66466515-c186-4792-b60a-4cd9c299e211/alerts/ids",
      "responseStatus" : 200,
      "location" : "RESPONSE",
      "pointers" : {
        "instance" : "/alerts/0",
        "schema" : "/properties/alerts/items"
      },
      "requestMethod" : "GET"
    }
  } ]
}
    at app//com.atlassian.oai.validator.mockmvc.OpenApiMatchers.lambda$isValid$0(OpenApiMatchers.java:58)
    at app//org.springframework.test.web.servlet.MockMvc$1.andExpect(MockMvc.java:212)

This happened when validating this body {"alerts":["d2b2cd6f-8349-4d1f-9629-572e5dc64e5a"]}, against the following entry of our openapi Json-Definition:

      "AlertIdsListResponse": {
        "required": [
          "alerts"
        ],
        "type": "object",
        "properties": {
          "alerts": {
            "type": "array",
            "items": {
              "type": "string"
            }
          },
          "next": {
            "$ref": "#/components/schemas/PaginationNextChunk"
          }
        }
      }

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