在Golang中模拟AWS开发工具包？

I am in a situation where I need to mock huge parts of the Lambda, API Gateway and S3 SDK packages for unit testing.

I initially thought this wouldn't be such a bad idea but right now having to implement some in-memory data storage and mimic the entire AWS logic for those services seems impossible (or at least really time consuming).

So basically my mock-implementation looks something like this

package awsmock

type Lambda struct {
    lambda.Lambda
    data map[string]*LambdaFunction
}

func (svc *Lambda) CreateFunction(...) (...) {
    // mimic the AWS logic but save to svc.data
}

// etc

Is there any better way you could think of when it comes to mocking AWS SDK? If there isn't, I could write a library and post it on Github so other can use it and improve it too, but I hope I can manage without reimplementing this.