[BUG][typescript-fetch] nullable arrays with a default null throws an error.

[yannickl88]

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)

We have a schema which can either be null or a list of object. This is mainly to allow the parameter to be optionally passed and to detect if the property was set to do case distinction on. So passing null vs [] behaves differently. (Similarly, as passing and empty string vs null)

However, when encoding this in a spec and trying to generate an typescript-fetch client for this, it results in an error.

Description

openapi-generator version

7.9.0

OpenAPI declaration file content or url

openapi: '3.0.3'

info:
  title: Test
  version: 0.1.0

paths: {}

components:
  schemas:
    Test:
      type: array
      items:
        type: string
      default: null
      nullable: true

Generation Details

$ java -jar "/node_modules/@openapitools/openapi-generator-cli/versions/7.9.0.jar" generate --input-spec="/test_schema.yaml" --generator-name="typescript-fetch" --output="/tmp/" --additional-properties="withInterfaces=true"
Exception in thread "main" org.openapitools.codegen.SpecValidationException: There were issues with the specification. The option can be disabled via validateSpec (Maven/Gradle) or --skip-validate-spec (CLI).
 | Error count: 1, Warning count: 3
Errors: 
     -attribute components.schemas.PaymentConfigurationResponse.default is not of type `array`
Warnings: 
     -attribute components.schemas.PaymentConfigurationResponse.default is not of type `array`

     at org.openapitools.codegen.config.CodegenConfigurator.toContext(CodegenConfigurator.java:717)
     at org.openapitools.codegen.config.CodegenConfigurator.toClientOptInput(CodegenConfigurator.java:744)
     at org.openapitools.codegen.cmd.Generate.execute(Generate.java:527)
     at org.openapitools.codegen.cmd.OpenApiGeneratorCommand.run(OpenApiGeneratorCommand.java:32)
     at org.openapitools.codegen.OpenAPIGenerator.main(OpenAPIGenerator.java:66)

Steps to reproduce

Run the command with the given schema

Related issues/PRs

None

Suggest a fix

null defaults are allowed when nullable, regardless of the type (array in this case).

[wing328]

please report the issue to https://github.com/swagger-api/swagger-parser which performs the validation

for the time being, please skip the validation (e.g. --skip-validate-spec in CLI) as mentioned in the error message

[yannickl88]

alrighty, thanks for pointing me to the correct project. I will close this issue then.