azure-functions-java-worker Node.js client call to Azure Functions Java requires Content-Length header set using 'https' package

When using a Node.js client app with the 'https' package, it requires the 'Content-Length' header to be set, otherwise the Azure Functions Java app will receive a 'null' body.

In contrast, using the same Node.js client and 'https' package to call a Azure Function written in dotnet/C# successfully receives the body without the 'Content-Length' header needing to be explicitly set on the client.

Repro steps

Provide the steps required to reproduce the problem:

Create a simple Node.js app. (See code below)
Use the 'https' npm package
Make a post call to the Azure Function (Java) without the 'Content-Length' header set.
The Azure Function (Java) receives a null body.
If you explicitly set the Content-Length, Azure Function (Java) receives the body.
Using the same Node.js app and calling to a Azure Function (C#) does not require the 'Content-Length' header set, and will successfully receive the body of the post request.

Expected behavior

Provide a description of the expected behavior.

When posting to the Azure Function (Java) using 'https' npm package, the 'Content-Length' header should not need to be set, and the Azure Function should receive the body.
This works as expected when calling Azure Function (C#), but does not work as expected when calling Azure Function (Java).

Actual behavior

Provide a description of the actual behavior observed.

When posting using 'https' npm package, to Azure Function (Java), the function receives a 'null' body if the 'Content-Length' header is not set.
When posting using 'https' npm package, to Azure Function (C#), the function successfully receives the body if the 'Content-Length' header is not yet.
The behavior is inconsistent between Azure Functions (Java) and Azure Functions (C#)

Known workarounds

Provide a description of any known workarounds.

Manually setting the 'Content-Length' header on the 'https' Node.js request being posted to the Azure Function (Java) allows the request to be received on the function.
This is not required when calling the Azure Function (C#).

Sample Code

Node.js Client App

var https = require('https');  

var xml = "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\r\n<Sale \r\n</Sale>\r\n";

// Using 'https' Library:
var options = {  
  host: '57c16559.ngrok.io',  
  port: 443,  
  path: '/api/HttpTrigger-Java',  
  //path: '/api/HttpTrigger-CSharp', 
  method: 'POST',
  headers: {
    'Content-Type': 'application/xml',
    // Azure Function (Java) requires 'Content-Length' set, otherwise it receives a 'null' body.
    // Azure Function (DotNet) doesn't require this, and successfully receives the body.
    //'Content-Length': xml.length 
  }
};  

var req = https.request(options, function(res) {  
  console.log("statusCode: ", res.statusCode);  
  console.log("headers: ", res.headers);  
  res.on('data', function(d) {   
    console.log(d);
  });  
});

req.write(xml)
req.end()

req.on('error', function(e) {  
  console.error(e);  
});

Azure Function (Java)

@FunctionName("HttpTrigger-Java")
    public HttpResponseMessage run(
            @HttpTrigger(name = "req", methods = {HttpMethod.POST}, authLevel = AuthorizationLevel.FUNCTION)
            HttpRequestMessage<Optional<String>> request,
            final ExecutionContext context) {
        context.getLogger().info("Java HTTP trigger processed a request.");

        // request.getBody() is 'null' if 'Content-Length' header is not set for Node.js 'https' package.

        return request.createResponseBuilder(HttpStatus.OK).body(request.getBody()).build();
    }

Azure Function (C#)

[FunctionName("HttpTrigger-CSharp")]
        public static async Task<IActionResult> Run(
            [HttpTrigger(AuthorizationLevel.Function, "post", Route = null)] 
            string body,
            HttpRequest req,
            ILogger log)
        {
            // body parameter does has a value if 'Content-Length' header is not set for Node.js 'https' package.

            return new OkObjectResult(body);
        }