[BUG] [TYPESCRIPT] HttpFile param is Serialized+Strignifyed but it makes the TS client crashing

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?
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Description

I'm supposed to upload a file (binary) with a PUT method, but the swagger-codegen generate a wrong TS function for my PUT function :

Here it should not Serialize nor Stringify my File, because it create this error on the client's side :

Instead, it should pass the dataSourceRequestData directly to the setBody()

openapi-generator version

latest, as of today on June 21, 2021

OpenAPI declaration file content or url

The .yml part of the route that produces this problematic code is :

  /datasources/{dataSourceId}/data:
      put:
        consumes:
          - 'application/octet-stream'
          - 'text/csv'
          - 'text/plain'
        tags:
          - 'api-metadata'
        summary: 'Add data to a datasource.'
        operationId: 'putDataSourceData'
        parameters:
          - in: 'path'
            name: 'dataSourceId'
            required: true
            type: 'string'
            pattern: '^[\w:-]+$'
            description: 'Data source identifier.'
          - in: 'body'
            name: 'dataSourceRequestData'
            description: 'Datasource data'
            required: true
            schema:
              type: string
              format: binary

Generation Details

The generation command is

docker run --rm -u "$(USER_GROUP)" -v "$(PWD)":/src openapitools/openapi-generator-cli:latest \
    -i /src/api/flattened.yml \
    -g typescript \
    -o /src/build/package/ts-client

Steps to reproduce

Run the above command with the above .yml

Related issues/PRs

No issue/PR related

Suggest a fix

I have actually no idea what could be the problem. Maybe there is a configuration I missed, but I more think this case should be automatically handled.

Start with flattened.yml and regenerate the client using the provided Docker command, then inspect the generated TypeScript PUT method under build/package/ts-client. Trace how the binary body schema is handled and verify that the generated client passes the file data directly to setBody() without serialization or stringification.