DefaultGenerator: unusedSchemas contains too many schemas

[jmini]

Some model object are missing when the server is configured to consume both application/json and application/x-www-form-urlencoded.

With this example the model SomeObject is not generated:

swagger: '2.0'
info:
  title: Test
  description: Test API
  version: 1.0.0
host: some.example.com
basePath: /v1
schemes:
  - https
  - http
consumes:
  - application/json
  - application/x-www-form-urlencoded
produces:
  - application/json
paths:
  /testMe:
    post:
      tags:
        - db
      operationId: testMeOp
      parameters:
        - in: body
          name: body
          required: false
          schema:
            $ref: '#/definitions/SomeObject'
      responses:
        '200':
          description: Successful Operation
definitions:
  SomeObject:
    type: object
    properties:
      p1:
        type: string
      p2:
        type: integer
        format: int32

This is due to org.openapitools.codegen.utils.ModelUtils.getUnusedSchemas(OpenAPI) not working as expected.

I am not sure if the dual consumes definition is correct or not (it is derived from a spec send by a used), but we could also imagine an other case with 2 path. In one JSON is expected as request body, in the other an application/x-www-form-urlencoded request body. In this case, the schema is also used.

In my opinion the logic to compute the unused schema should be to compute all the used schema and subtract them from a set containing all schemas.

[jmini]

Propose PR #74

[tonymurphy]

I was trying to use openapi to generate a client for keycloak - and it doesn't work because requestBody of content type application/x-www-form-urlencoded don't seem to be supported? it's not clear in the documentation tbh

openapi: 3.0.0
info:
  title: Keycloak Open ID Connect API
  version: '1.0'
  description: Open API Definition for Authentication
servers:
    description: Identity Server
  - url: 'http://localhost:8080'
    description: Localhost
tags:
  - name: 'Open ID Connect'
paths:
  /auth/realms/demo/protocol/openid-connect/token:
    post:
      summary: Direct Access Grant
      description: 'https://tools.ietf.org/html/rfc6749#section-10.7'
      tags:
        - 'Open ID Connect'
      operationId: directAccessGrantCode
      requestBody:
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/AccessTokenRequest'
        required: true
      responses:
        '200':
          description: OK
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/AccessTokenResponse'
        '401':
          description: Not authenticated
        '403':
          description: Access denied
  /auth/realms/demo/protocol/openid-connect/logout:
    post:
      summary: Logout
      description: Remove Session from Keycloak
      tags:
        - 'Open ID Connect'
      operationId: logout
      requestBody:
        content:
          application/x-www-form-urlencoded:
            schema:
              type: object
              properties:
                refresh_token:
                  type: string
      responses:
        '204':
          description: OK
        '401':
          description: Not authenticated
        '403':
          description: Access denied
components:
  schemas:
    AccessTokenRequest:
      type: object
      properties:
        client_id:
          type: string
        client_secret:
          type: string
        grant_type:
          type: string
        scope:
          type: string
        username:
          type: string
        password:
          type: string
      required:
        - client_id
        - client_secret
        - grant_type
        - scope
        - username
        - password
    AccessTokenResponse:
      type: object
      properties:
        access_token:
          type: string
        expires_in:
          type: integer
        refresh_expires_in:
          type: integer
        refresh_token:
          type: string
        token_type:
          type: string
        id_token:
          type: string
        not-before-policy:
          type: integer
          format: int64
        session_state:
          type: string
        scope:
          type: string

the following works
curl -X POST "https://localhost:8080/auth/realms/demo/protocol/openid-connect/token" -H "accept: */*" -H "Content-Type: application/x-www-form-urlencoded" -d 'client_id=demo-client&client_secret=****&grant_type=password&scope=openid%20offline_access&username=tonymurphy%40demo.com&password=abc123'

but the following does not..
curl -X POST "https://localhost:8080/auth/realms/demo/protocol/openid-connect/token?client_id=demo-client&client_secret=****&grant_type=password&scope=openid%20offline_access&username=tonymurphy%40demo.com&password=abc123" -H "accept: application/json" -H "Content-Type: application/x-www-form-urlencoded"