Here are the units tests that can be found in the middle of serverless-microservice-data-api/test/test_dynamo_get.py:

    def test_validparameters_parseparameters_pass(self):
        parameters = lambda_query_dynamo.HttpUtils.parse_parameters(
                     self.validJsonDataStartDate)
        assert parameters['parsedParams']['startDate'] == u'20171013'
        assert parameters['parsedParams']['resource_id'] == u'324'     

    def test_emptybody_parsebody_nonebody(self):
        body = lambda_query_dynamo.HttpUtils.parse_body(
               self.validJsonDataStartDate)         
        assert body['body'] is None

    def test_invalidjson_getrecord_notfound404(self):
        result = lambda_query_dynamo.Controller.get_dynamodb_records(
                 self.invalidJsonData)
        assert result['statusCode'] == '404'

    def test_invaliduserid_getrecord_invalididerror(self):            
        result = lambda_query_dynamo.Controller.get_dynamodb_records(
                 self.invalidJsonUserIdData)
        assert result['statusCode'] == '404'
        assert json.loads(result['body'])['message'] == 
             "resource_id not a number" 

I'm using a prefix of test so Python test suites can automatically detect them as unit tests, and I'm using the triplet unit test naming convention for the test methods: the method name, the state under test, and the expected behavior. The test methods are as follows:

• test_validparameters_parseparameters_pass(): Checks that the parameters are parsed correctly.
• test_emptybody_parsebody_nonebody(): We are not using a body in the GET method, so we want to make sure that it still works if none is provided.
• test_invalidjson_getrecord_notfound404(): Check how the Lambda will react with an invalid JSON payload.
• test_invaliduserid_getrecord_invalididerror(): Check how the Lambda will react to an invalid non-number userId.

The preceding does not query DynamoDB for the records. If we want to do so, we should have DynamoDB running, use the new DynamoDB Local (https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/DynamoDBLocal.html), or we can mock the DynamoDB calls, which is what we will look at next.