[typescript] Endpoint with string content produces unbuildable code

With the following input:

openapi: 3.0.1
info:
  title: Data
  description: Services for general drinkaware data
  version: 1.0.0
paths:
  /:
    get:
      operationId: Home
      summary: Get Home Page
      responses:
        '200':
          description: Home page
          content:
            text/plain; utf-8:
              schema:
                type: string
                pattern: '^.*$'
                maxLength: 1000
                example: unauthorized 

The typescript emitter creates a data.ts file with the following specification:

const homeOperationSpec: coreHttp.OperationSpec = {
  path: "/",
  httpMethod: "GET",
  responses: {
    200: {
      bodyMapper: {
        type: { name: "String" },
        constraints: { MaxLength: 1000, Pattern: {} }
      }
    }
  },
  urlParameters: [Parameters.$host],
  headerParameters: [Parameters.accept],
  serializer
};

The bodyMapper property cannot be mapped to a valid type:

      TS2322: Type '{ type: { name: "String"; }; constraints: { MaxLength: number; Pattern: {}; }; }' is not assignable to type 'BaseMapper | CompositeMapper | SequenceMapper | DictionaryMapper | EnumMapper | undefined'.
  Type '{ type: { name: "String"; }; constraints: { MaxLength: number; Pattern: {}; }; }' is not assignable to type 'EnumMapper'.
    Types of property 'type' are incompatible.
      Property 'allowedValues' is missing in type '{ name: "String"; }' but required in type 'EnumMapperType'.

Expected behavior Valid YAML produces a valid typescript file

Additional context

AutoRest code generation utility [cli version: 3.1.2; node: v12.18.2, max-memory: 2048 MB]
(C) 2018 Microsoft Corporation.
https://aka.ms/autorest

There is a new version of AutoRest available (3.2.0).
 > You can install the newer version with with npm install -g autorest@latest

   Loading AutoRest core      '/home/craignicol/.autorest/@autorest_core@3.0.6375/node_modules/@autorest/core/dist' (3.0.6375)
   Loading AutoRest extension '@autorest/typescript' (6.0.0-dev.20201105.2->6.0.0-dev.20201105.2)
   Loading AutoRest extension '@autorest/modelerfour' (4.15.421->4.15.421)

[timotheeguerin]

Seems to be an issue with the typescript generator itself here, will transfer to their repo

[sarangan12]

Fixed it with the PR https://github.com/Azure/autorest.typescript/pull/1426. No more action items pending on this issue. Closing it now. Feed free to reopen if you face this issue again. Thanks