How to set content type on MultipartFile by looking up mime type?

[Yogesh070]

Describe the bug A clear and concise description of what the bug is.

To Reproduce Steps to reproduce the behavior: I have defined the api as:

@POST('') Future saveProfileGreetings( @Part() File file, @Part() String link, @SendProgress() ProgressCallback onSendProgress, );

This works fine but I want to assign content type on MultipartFile by looking up mime type.

Expected behavior I want to generate the api as the following where i can set content type as :

contentType: MediaType.parse(lookupMimeType(file.path)!),

@override Future saveProfileGreetings( File file, String link, void Function(int, int) onSendProgress, ) async { final _extra = <String, dynamic>{}; final queryParameters = <String, dynamic>{}; final _headers = <String, dynamic>{}; final _data = FormData(); _data.files.add(MapEntry( 'file', MultipartFile.fromFileSync( file.path, filename: file.path.split(Platform.pathSeparator).last, contentType: MediaType.parse(lookupMimeType(file.path)!), ), )); _data.fields.add(MapEntry( 'link', link, )); await _dio.fetch(_setStreamType(Options( method: 'POST', headers: _headers, extra: _extra, contentType: 'multipart/form-data', ) .compose( _dio.options, '', queryParameters: queryParameters, data: _data, onSendProgress: onSendProgress, ) .copyWith( baseUrl: _combineBaseUrls( _dio.options.baseUrl, baseUrl, )))); }

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