Make a new test for proper edge merging

[tokebe]

As noted by @andrewsu, #390 is a good issue to turn into a module-level test for proper edge merging.

This query is a good test query to create simplified internal objects for this test

{
    "message": {
        "query_graph": {
            "edges": {
                "e00": {
                    "subject": "n00",
                    "object": "n01",
                    "predicates": ["biolink:affects_risk_for"]
                }
            },
            "nodes": {
                "n00": {
                    "categories": ["biolink:SmallMolecule"],
                    "ids": ["UMLS:C0040329"]
                },
                "n01": {
                    "categories": ["biolink:Disease"],
                    "ids": ["UMLS:C0242379"]
                }
            }
        }
    }
}

[rjawesome]

@tokebe What exactly is a simplified internal object and how would I go about creating/testing it?

[tokebe]

@rjawesome You can save Record objects, which are created from the responses of queried APIs and used throughout results-assembly, etc., by running BTE with the environment variable DUMP_RECORDS=path/to/fileToCreate.json (or by pausing execution after Records have been created+annotated and using built-in Record methods, though this is a little more complicated).

You'll want to write this test in the query_graph_handler test files -- The behavior you'll be testing was fixed by this PR, which hopefully gives an idea of where to start. If not, shoot me a message and I can try to clarify what part of query execution this test should be focused on.

From here you can write a test which supplies these records and expects specific edge-merging behavior (as shown in the original issue). You'll need to import the Record class and "un-freeze" your saved objects.

[rjawesome]

@tokebe To confirm, these are the two things to test:

1. Test the behavior of the is_set parameter
2. Test that same records with different predicates aren't merged?

Is there anything else that I am missing?

[tokebe]

You only need to test that records that are otherwise the same but have different predicates are not merged into one response edge/result. No worries for is_set as far as this issue is concerned.