public static Mock<HttpRequestData> HttpRequestDataMock(string data, HttpStatusCode httpStatusCode = HttpStatusCode.OK)
{
  Mock<FunctionContext> functionContextMock = new();
  HttpHeadersCollection headers = new() { { "Authorization", new List<string?> { "Bearer token" } } };
  headers.Add("content-type", "application/json");

  Mock<HttpRequestData> httpRequestDataMock = new(functionContextMock.Object);
  httpRequestDataMock.Setup(r => r.Headers).Returns(headers);
  httpRequestDataMock.Setup(r => r.Body).Returns(data.CreateMemoryStream());
  httpRequestDataMock.Setup(r => r.CreateResponse()).Returns(() =>
  {
    Mock<HttpResponseData> httpResponseData = new(functionContextMock.Object);
    httpResponseData.SetupProperty(s => s.Headers, headers);
    httpResponseData.SetupProperty(s => httpStatusCode);
    httpResponseData.SetupProperty(s => s.Body, new MemoryStream());
    return httpResponseData.Object;
  });

  return httpRequestDataMock;
}

public static Mock<HttpRequestData> HttpRequestDataMock(string data, HttpStatusCode httpStatusCode = HttpStatusCode.OK)
{
  Mock<FunctionContext> functionContextMock = new();
  HttpHeadersCollection headers = new() { { "Authorization", new List<string?> { "Bearer token" } } };
  headers.Add("content-type", "application/json");

  Mock<HttpRequestData> httpRequestDataMock = new(functionContextMock.Object);
  httpRequestDataMock.Setup(r => r.Headers).Returns(headers);
  httpRequestDataMock.Setup(r => r.Body).Returns(data.CreateMemoryStream());
  httpRequestDataMock.Setup(r => r.CreateResponse()).Returns(() =>
  {
    Mock<HttpResponseData> httpResponseData = new(functionContextMock.Object);
    httpResponseData.SetupProperty(s => s.Headers, headers);
    httpResponseData.SetupProperty(s => httpStatusCode);
    httpResponseData.SetupProperty(s => s.Body, new MemoryStream());
    return httpResponseData.Object;
  });

  return httpRequestDataMock;
}

Mock<HttpRequestData> request = HttpRequestDataMock(validPayload);
using StreamReader reader = new(request.Object.Body, encoding: System.Text.Encoding.UTF8, leaveOpen: true);
string bodyResult = await reader.ReadToEndAsync();

Mock<HttpRequestData> request = HttpRequestDataMock(validPayload);
using StreamReader reader = new(request.Object.Body, encoding: System.Text.Encoding.UTF8, leaveOpen: true);
string bodyResult = await reader.ReadToEndAsync();

using StreamReader reader = new(request.Object.Body, encoding: System.Text.Encoding.UTF8, leaveOpen: true);
string bodyResult = await reader.ReadToEndAsync();

using StreamReader reader = new(request.Object.Body, encoding: System.Text.Encoding.UTF8, leaveOpen: true);
string bodyResult = await reader.ReadToEndAsync();