OpenAPI parameter name of only an underscore results in missing parameter name in services.gen.ts

[Beauchaj]

Describe the bug
An OpenAPI Query Parameter with the name _ (or any _ within the parameter name) fails to generate the corresponding property name under services.gen.ts (Fetch client). Any instance of _ is being stripped from the resulting value (leading, trailing, or otherwise) in the translation of the snake_case OpenAPI parameter key to the camelCase property name, but if the parameter name is only _ the generated ts is broken.

Noting: If the parameter was _ the query parameter generated under services.gen.ts is:

      query: {
        _: data.,
      },

instead of

      query: {
        _: data._,
      },

Also noting: Using _ as a name or character parameter in OpenAPI queries does not break the OpenAPI specification.

To Reproduce
Steps to reproduce the behavior:

Call the following openapi yaml using

yarn openapi-rq -i ./openapi.yaml

OpenAPI spec file

openapi: 3.1.0
info:
  title: Test API
  description: API for Test
  version: development
security:
  - test_auth:
      - default
paths:
  /reachable:
    head:
      summary: Reachable?
      description: Does nothing and returns No Content
      operationId: reachable
      security: []
      parameters:
        - name: _
          in: query
          description: Optional parameter for avoiding caching
          schema: {}
      responses:
        '204':
          description: Success

Expected behavior
A clear and concise description of what you expected to happen.

Expected output

export class DefaultService {
  /**
   * Reachable?
   * Does nothing and returns No Content
   * @param data The data for the request.
   * @param data._ Optional parameter for avoiding caching
   * @returns void Success
   * @throws ApiError
   */
  public static reachable(
    data: ReachableData = {},
  ): CancelablePromise<ReachableResponse> {
    return __request(OpenAPI, {
      method: "HEAD",
      url: "/reachable",
      query: {
        _: data._,
      },
    });
  }
}

Instead got output

export class DefaultService {
    /**
     * Reachable?
     * Does nothing and returns No Content
     * @param data The data for the request.
     * @param data. Optional parameter for avoiding caching
     * @returns void Success
     * @throws ApiError
     */
    public static reachable(data: ReachableData = {}): CancelablePromise<ReachableResponse> {
        return __request(OpenAPI, {
            method: 'HEAD',
            url: '/reachable',
            query: {
                _: data.
            }
        });
    }
    
}

Screenshots
If applicable, add screenshots or logs to help explain your problem.

• OS: Linuxmint
• Version
  Description: Linux Mint 21.3
  Release: 21.3
  Codename: virginia
• Node version: v20.14.0

Relevant package versions:

  "devDependencies": {
    "@7nohe/openapi-react-query-codegen": "^1.4.1",
    "@tanstack/eslint-plugin-query": "^5.43.1",
    "@types/react": "^18.0.27",
    "@types/react-dom": "^18.0.10",
    "commander": "^12.1.0",
    "ts-morph": "^22.0.0",
    "typescript": "^5.1.6",
  },
  "packageManager": "yarn@4.3.0"

[Beauchaj]

Now raised in hey-api/openapi-ts#726