[BUG][kotlin] Kotlin generated code does not compile when parameter name contains $

Created by: sarod

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• What's the version of OpenAPI Generator used?
• Have you search for related issues/PRs?
• What's the actual output vs expected output?

Description

Kotlin generator generates invalid code when parameter name contain $

openapi-generator version

4.0.0-beta2

OpenAPI declaration file content or url

openapi: "3.0.0"
info:
  version: "1.0.0"
  title: Swagger Petstore
  license:
    name: MIT
servers:
  - url: http://petstore.swagger.io/v1
paths:
  /pets/{$petId}:
    get:
      summary: Info for a specific pet
      operationId: showPetById
      tags:
        - pets
      parameters:
        - name: $petId
          in: path
          required: true
          description: The id of the pet to retrieve
          schema:
            type: string
      responses:
        "200":
          description: Expected response to a valid request
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/Pets"
        default:
          description: unexpected error
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/Error"
components:
  schemas:
    Pet:
      required:
        - id
        - name
      properties:
        id:
          type: integer
          format: int64
        name:
          type: string
        tag:
          type: string
    Pets:
      type: array
      items:
        $ref: "#/components/schemas/Pet"
    Error:
      required:
        - code
        - message
      properties:
        code:
          type: integer
          format: int32
        message:
          type: string

Command line used for generation

Using the open api above as the content of petstore.yaml openapi-generator generate -i ./petstore.yaml -g kotlin

Steps to reproduce

• Copy the OpenAPI declaration file content to petstore.yaml
• Generate using openapi-generator generate -i ./petstore.yaml -g kotlin
• Follow the README instructions:
  • gradle wrapper
  • ./gradlew check assemble

Fails with

e: generator-test/src/main/kotlin/org/openapitools/client/apis/PetsApi.kt: (28, 21): Parameter name expected
e: generator-test/src/main/kotlin/org/openapitools/client/apis/PetsApi.kt: (28, 22): Expecting comma or ')'
e: generator-test/src/main/kotlin/org/openapitools/client/apis/PetsApi.kt: (28, 22): Expecting ')'
e: generator-test/src/main/kotlin/org/openapitools/client/apis/PetsApi.kt: (28, 23): Expecting member declaration
e: generator-test/src/main/kotlin/org/openapitools/client/apis/PetsApi.kt: (28, 27): Expecting member declaration
e: generator-test/src/main/kotlin/org/openapitools/client/apis/PetsApi.kt: (28, 33): Expecting member declaration
e: generator-test/src/main/kotlin/org/openapitools/client/apis/PetsApi.kt: (28, 34): Expecting member declaration
e: generator-test/src/main/kotlin/org/openapitools/client/apis/PetsApi.kt: (28, 35): Expecting member declaration
e: generator-test/src/main/kotlin/org/openapitools/client/apis/PetsApi.kt: (28, 39): Expecting member declaration
e: generator-test/src/main/kotlin/org/openapitools/client/apis/PetsApi.kt: (28, 41): Expecting member declaration
e: generator-test/src/main/kotlin/org/openapitools/client/apis/PetsApi.kt: (28, 47): Expecting member declaration
e: generator-test/src/main/kotlin/org/openapitools/client/apis/PetsApi.kt: (28, 48): Expecting member declaration
e: generator-test/src/main/kotlin/org/openapitools/client/apis/PetsApi.kt: (28, 54): Expecting member declaration
e: generator-test/src/main/kotlin/org/openapitools/client/apis/PetsApi.kt: (28, 56): Expecting member declaration
e: generator-test/src/main/kotlin/org/openapitools/client/apis/PetsApi.kt: (28, 58): Expecting member declaration
e: generator-test/src/main/kotlin/org/openapitools/client/apis/PetsApi.kt: (28, 64): Expecting member declaration
e: generator-test/src/main/kotlin/org/openapitools/client/apis/PetsApi.kt: (28, 65): Expecting member declaration
e: generator-test/src/main/kotlin/org/openapitools/client/apis/PetsApi.kt: (28, 70): Expecting member declaration
e: generator-test/src/main/kotlin/org/openapitools/client/apis/PetsApi.kt: (28, 71): Expecting member declaration
e: generator-test/src/main/kotlin/org/openapitools/client/apis/PetsApi.kt: (28, 74): Expecting member declaration
e: generator-test/src/main/kotlin/org/openapitools/client/apis/PetsApi.kt: (28, 76): Expecting member declaration
e: generator-test/src/main/kotlin/org/openapitools/client/apis/PetsApi.kt: (28, 76): Function declaration must have a name
e: generator-test/src/main/kotlin/org/openapitools/client/apis/PetsApi.kt: (34, 22): Unresolved reference: petId
e: generator-test/src/main/kotlin/org/openapitools/client/apis/PetsApi.kt: (34, 44): Unresolved reference: petId
e: generator-test/src/main/kotlin/org/openapitools/client/apis/PetsApi.kt: (34, 65): Unresolved reference: petId
e: generator-test/src/main/kotlin/org/openapitools/client/apis/PetsApi.kt: (44, 37): Type mismatch: inferred type is Array<Pet> but Unit was expected

Related issues/PRs

No related issue

Suggest a fix

$ should be escaped when used in kotlin strings names