Maintenance: Increase unit test coverage

[jeromevdl]

Summary

Based on https://app.codecov.io/github/aws-powertools/powertools-lambda-java, increase the unit test coverage on modules which are under 80%: core, logging, validation, parameters & serialization

Why is this needed?

As powertools for java becomes more popular, we need to make sure we are well covered with unit tests. Objective is not to increase the coverage for the numbers but to make sure there is nothing left untested.

Which area does this relate to?

Tests

Solution

No response

Acknowledgment

• This request meets Lambda Powertools Tenets
• Should this be considered in other Lambda Powertools languages? i.e. Python, TypeScript

[eldimi]

I will start working on this. It is not possible to set myself as an assignee for the time being.
Also, including the updated code coverage location

[jeromevdl]

@eldimi, any help needed, any progress so far?

[eldimi]

@eldimi, any help needed, any progress so far?

I just added this PR for review

[jeromevdl]

closed with #1264, great improvement of the coverage: https://app.codecov.io/gh/aws-powertools/powertools-lambda-java/tree/main