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

If there is no title, the rust generator tries to derive a meaningful name from the type (see #17896). However, this fails in some cases, for example if there is a oneOf with multiple arrays inside.

The OpenAPI spec below produces the following enum:

#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
#[serde(untagged)]
pub enum Option1OrOption2Options {
    Array(Vec<String>),
    Array(Vec<i32>),
}

This cannot be compiled, the error message is error[E0428]: the name 'Array' is defined multiple times. I would expect that all code generated from a valid OpenAPI spec generates compilable rust code.

openapi-generator version

I tested with version 06ed7c8 (the current main).

OpenAPI declaration file content or url

openapi: 3.0.0
info:
  title: oneOf with arrays
  description: Ensure different names for kinds in enum when using oneOf with arrays.
  version: 1.0.0
paths: {}
components:
  schemas:
    Option1OrOption2:
      type: object
      properties:
        Options:
          oneOf:
            - type: array
              items:
                type: string
            - type: array
              items:
                type: integer

Steps to reproduce

I'll provide the steps to create a failing test using the valid OpenAPI spec above.

• Add the snippet above to the test resources (e.g. modules/openapi-generator/src/test/resources/3_0/rust/oneof-with-arrays.yaml).

• Create a config for the test (e.g. bin/configs/rust-reqwest-oneOf-with-arrays.yaml):

  generatorName: rust
  outputDir: samples/client/others/rust/reqwest/oneOf-with-arrays
  library: reqwest
  inputSpec: modules/openapi-generator/src/test/resources/3_0/rust/oneof-with-arrays.yaml
  templateDir: modules/openapi-generator/src/main/resources/rust
  additionalProperties:
    supportAsync: false
    packageName: oneof-with-arrays-reqwest

• Generate the rust samples with ./bin/generate-samples.sh ./bin/configs/rust-*.

• Execute the tests with mvn integration-test -f samples/client/others/rust/pom.xml.

Related issues/PRs

• Not long ago, the rust type was directly used as the enum kind, see [BUG][Rust] oneOf with array produces invalid code #17896.
• This was changed in fix(rust): oneOf generation for client #17915 solving [BUG][Rust] oneOf with array produces invalid code #17896.
• [BUG] Code generation is broken for oneOf types (Rust Server) #17210 is a follow up issue but it's different from the issue I am opening here.

Suggest a fix

I'm new to rust and to openapi-generator, so I am no help here, sorry.