[BUG][csharp-netcore] No provision to pass cookies to the ApiClient

Created by: vvb

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• Have you validated the input using an OpenAPI validator (example)?
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Description

Their is a provision to pass headers in the configuration using DefaultHeaders. But passing cookie here does not seem to work.

For the below code, a wire capture shows the origin header, but cookie param is not found in the message. It gets saved into DefaultParameters but not consumed.

Org.OpenAPITools.Client.Configuration config = new Org.OpenAPITools.Client.Configuration();
var api = new Org.OpenAPITools.Api.NtpApi(config);
var url = endpoint + "ntp/Policies";
var intersightHeaders = new Dictionary<string, string>()
{
    { "cookie", "Param="+Value },
    { "origin", url }
};
foreach (var h in intersightHeaders)
{
    api.Configuration.DefaultHeaders.Add(h.Key, h.Value);
}

openapi-generator version

latest master

OpenAPI declaration file content or url

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Related issues/PRs

Suggest a fix

We could make a change in the ApiClient, if it comes across a header with Name "Cookie", then it could do the below instead.

diff --git a/modules/openapi-generator/src/main/resources/csharp-netcore/ApiClient.mustache b/modules/openapi-generator/src/main/resources/csharp-netcore/ApiClient.mustache
index 49b81c72e0..8592f55720 100644
--- a/modules/openapi-generator/src/main/resources/csharp-netcore/ApiClient.mustache
+++ b/modules/openapi-generator/src/main/resources/csharp-netcore/ApiClient.mustache
@@ -271,6 +271,21 @@ namespace {{packageName}}.Client
             {
                 foreach (var headerParam in configuration.DefaultHeaders)
                 {
+                   if (String.Equals(headerParam.Key, "cookie", StringComparison.OrdinalIgnoreCase))
+                    {
+                        string[] cookieSeparators = new string[] {";"};
+                        string[] EqualSeparator = new string[] {"="};
+                        string[] rawCookieParams = headerParam.Value.Split(cookieSeparators, StringSplitOptions.None);
+                        foreach (string paramset in rawCookieParams)
+                        {
+                            String[] param = paramset.Split(EqualSeparator, StringSplitOptions.None);
+                            if (param.Length == 2)
+                            {
+                                request.AddCookie(param[0], param[1]);
+                            }
+                        }
+                        continue;
+                    }
                     request.AddHeader(headerParam.Key, headerParam.Value);
                 }
             }