[JavaScript] Client sets Content-Type for multipart/form-data which causes a missing boundary in the header

[Danielku15]

Description

When uploading files via Ajax and FormData, you must not set the Content-Type header which is done here. This will cause the browser to really send a header Content-Type: multipart/form-data which is wrong. If you do not set this header explicitely it will set the header to something like Content-Type: multipart/form-data; boundary=----WebKitFormBoundaryhwk47FtsDeemWl3V. So basically the boundary is missing which makes it impossible for the server side to parse the body.

Swagger-codegen version

Latest

Swagger declaration file content or url

PetStore sample is also affected.
https://github.com/swagger-api/swagger-codegen/blob/master/samples/client/petstore/javascript/src/ApiClient.js#L379

Command line used for generation

Default parameters, see PetStore. We also use browserify to really use it in the browser, not in node.js.

Steps to reproduce

Define a file parameter on your API, make a call using the generated API. When checking the Content-Type header on the server-side you will see the missing boundary.

Related issues

swagger-api/swagger-editor#666
swagger-api/swagger-editor#995
swagger-api/swagger-ui#662

Suggest a Fix

In this if-block the first statement should be:

    } else if (contentType == 'multipart/form-data') {
      request.unset('Content-Type'); // unset content type for auto generation by browser
      var _formParams = this.normalizeParams(formParams);
      for (var key in _formParams) {

[wing328]

@Danielku15 thanks for reporting the issue and proposing a fix. What if the auto-generated JS API client is used in other environments (e.g. Node) other than browser?

[triptec]

@wing328 I've had the same problem and made this PR #3932 but this here is basically the same solution, not setting the content-type if it is multipart. I can confirm that it works in node (5.10.1)

[wing328]

@triptec thanks for filing a fix and performing tests in Node environment to confirm. I'll review your PR shortly.

[triptec]

This should be solved #3932

[c094728]

I am using the lastest version of swagger-node-express 2.1.3 and have this problem and file upload would not work. I was able to get it to work by completely removing the consumes directive which I had set to multipart/form-data. removing this allowed it to work.
consumes:
- multipart/form-data

[c094728]

It can't seem to handle a file upload combined with a json body though. body-parser gets Unexpected token # in JSON at position 0

- path: /api/v1/uploadZip/file
  operations:

  - httpMethod: POST
    summary: Upload File
    notes: "Upload file to artifactory"
    nickname: fileUpload
  
    responses:
      200:
        description: upload file
    parameters:

    - name: body
      paramType: body
      dataType: Publication
      required: true
      description: publication

    - name: zipFile
      description: zip file
      paramType: form
      required: true
      dataType: file

[SteveRuben]

@c094728 you can handle file as a json. this is not possible.