Inject a GetOrCreateMixin to Node and Relationship.

[aalekhpatel07]

Description

Add a Django-like get_or_create() shortcut for Node and Relationship to simplify the following idiom of merging nodes and relationships:

Before:

try:
    streamer = Streamer(id="3").load(db=db)
except:
    print("Creating new Streamer node in the database.")
    streamer = Streamer(id="3", username="anne", followers=222).save(db=db)

After:

streamer, created = Streamer(id="3").get_or_create(db=db)
# only update if its created.
if created:
    streamer.username = "anne"
    streamer.followers = 222
    streamer.save(db=db)

Pull request type

• Feature
• Refactoring with functional or API changes

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

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Reviewer checklist (the reviewer checks this part)

• Core feature implementation
• Tests
• Code documentation
• Documentation on memgraph/docs

######################################

[katarinasupe]

Hi @aalekhpatel07, thank you for the contribution. We will check it asap, and get back to you. For now, can you rebase to main, since we changed our development process (I updated the Contribution guide now)?

[aalekhpatel07]

The changelist should be atomic and more manageable now.

[katarinasupe]

Hi @aalekhpatel07 :) I managed to look at the PR, and it all seems good. Can you maybe add a test (similar to what you provided above) here? If not, please let me add commits if you didn't allow it before. Again, thanks for the contribution.

[katarinasupe]

If you can, please add at least one test. Ideally, check the procedure both for node and relationship object.

[aalekhpatel07]

I've added a couple of tests.

Unfortunately, pymgclient is broken for me, so poetry install is a bit of a pain because I have to install pymygclient separately.

I'll let CI be the judge for these tests.

[aalekhpatel07]

Thank you for approving the CI run. that helped spot a couple of tiny mistakes. Lets try running it again? This might be a couple of iterations since CI is the only feedback for me, but we'll get there soon.

[katarinasupe]

You can also test it locally with
poetry run pytest . -k "not slow and not extras"
and running Memgraph instance. The only tests failing then should be Neo4j ones.

[aalekhpatel07]

Okay, all test_get_or_create tests are passing now. 🥳 There's a spurious failing test tests/graph_algorithms/test_query_builder.py::test_memgraph_query_builder_methods_exist that doesn't seem related to my changelist.

I went with setting up a neo4j and a memgraph instance in the background while running the tests locally:

docker run \
    --name neo4j \
    -p 7688:7687 \
    -p 7474:7474 \
    -e NEO4J_AUTH="neo4j/test" \
    --rm \
    -it neo4j:4.4.7

docker run \
    --name memgraph \
    -p 7687:7687 \
    -p 3000:3000 \
    --rm \
    -it memgraph

poetry run pytest . -k 'not slow and not extras'

[katarinasupe]

Hi @aalekhpatel07, your test are passing now! Sorry for being a bit late on running them. We will push this PR to the next release. I will update you on when that is. Is our release timeline a blocker for you?

[aalekhpatel07]

Not really. Next release seems reasonable. It's mostly a qol improvement at this point.