Lambda client wrapper #13
Description
Describe the story
Create a Lambda client utility which serves as a wrapper around the AWS SDK LambdaClient. This should simplify the creation of the AWS SDK Lambda client and it should store the created instance as a singleton for reuse across Lambda function invocations.
The wrapper should provide invokeLambdaSync and invokeLambdaAsync helper functions which invoke a Lambda function synchronously or asynchronously respectively. Both helper functions should send a JSON payload to the target Lambda function.
The wrapper should provide a getter which returns the singleton instance of the LambdaClient.
Acceptance criteria
GIVEN the app initializes an instance of the Lambda client
WHEN no parameters are supplied to the initializer
THEN an instance of the client is created using the default configuration for the LambdaClient
WHEN the LambdaClientConfig is provided to the initializer
THEN the LambdaClient instance is constructed using the supplied configuration
WHEN the LambdaClient instances are constructed
THEN they are cached as singleton instances
GIVEN the invokeLambdaSync function is invoked
WHEN the singleton instance does not exist
THEN a LambdaClient instance is constructed with default configuration
AND the instance is cached as the singleton
AND the instance is used by the invokeLambdaSync function to synchronously invoke the target function
AND the response is examined for a FunctionError
AND the function logs and throws an Error if a problem occurs
AND the function returns the response payload if successful
WHEN the singleton instance already exists
THEN the existing singleton instance is used by the invokeLambdaAsync function
GIVEN the invokeLambdaAsync function is invoked
WHEN the singleton instance does not exist
THEN a LambdaClient instance is constructed with default configuration
AND the instance is cached as the singleton
AND the instance is used by the invokeLambdaAsync function to synchronously invoke the target function
AND the response is examined for a FunctionError
AND the function logs and throws an Error if a problem occurs
WHEN the singleton instance already exists
THEN the existing singleton instance is used by the invokeLambdaAsync function
Additional context
Add any other context about the story here.