public async Task TestDetectInvalidChannelFunction()
        {
            // Invoke the lambda function and confirm the string was upper cased.
            var function = new Function();
            var context  = new TestLambdaContext();

            var input = new ChatworkInput
            {
                Channel = 0,
                Text    = "Send from AWS Lambda"
            };

            Assert.Throws <AggregateException>(() => function.FunctionHandler(input, context).Result);
        }
        public async Task TestDetectInvalidTextFunction()
        {
            // Invoke the lambda function and confirm the string was upper cased.
            var function = new Function();
            var context  = new TestLambdaContext();

            var input = new ChatworkInput
            {
                Channel = int.Parse(Environment.GetEnvironmentVariable("ChatworkChannel")),
                Text    = ""
            };

            Assert.Throws <AggregateException>(() => function.FunctionHandler(input, context).Result);
        }
        public async Task TestSucessFunction()
        {
            // Invoke the lambda function and confirm the string was upper cased.
            var function = new Function();
            var context  = new TestLambdaContext();

            var input = new ChatworkInput
            {
                Channel = int.Parse(Environment.GetEnvironmentVariable("ChatworkChannel")),
                Text    = "Send from AWS Lambda"
            };
            var result = await function.FunctionHandler(input, context);

            Assert.IsType <int>(result);
        }