[master < T507-FL] EmptyResult operator

[as51340]

[master < Epic] PR

• Check, and update documentation if necessary
• Update changelog
• Write E2E tests
• Compare the benchmarking results between the master branch and the Epic branch
• Provide the full content or a guide for the final git message

[master < Task] PR

• Check, and update documentation if necessary
• Update changelog
• Provide the full content or a guide for the final git message

Closes #650

[kostasrim]

Preliminary review as asked

[gitbuda]

There is some commented code + some form of testing is missing.

I would add a new test here -> https://github.com/memgraph/memgraph/tree/master/tests/gql_behave/tests/memgraph_V1, but probably there are other viable options 😄

[as51340]

There is some commented code + some form of testing is missing.

I would add a new test here -> https://github.com/memgraph/memgraph/tree/master/tests/gql_behave/tests/memgraph_V1, but probably there are other viable options smile

I changed all unit tests that make use of this new operator, doesn't this suffice?

[antaljanosbenjamin]

The operator looks good, but on the planner side I am not sure if the logic is correct.

[gitbuda]

There is some commented code + some form of testing is missing.
I would add a new test here -> https://github.com/memgraph/memgraph/tree/master/tests/gql_behave/tests/memgraph_V1, but probably there are other viable options smile

I changed all unit tests that make use of this new operator, doesn't this suffice?

In general, unit tests are great, but the e2e test helps you to:

• get real confidence the feature is really working
• spot some weird bugs which are not detectable by simply thinking about a small unit of testing
  That being said, if nothing else, I would add at least one e2e test query, if nothing else for the sale of sanity check 😄

[gitbuda]

The e2e test I've mentioned has been added so I'll approve this PR