Reducing flakiness in the tests

[kafkasl]

Background

Link to issue

https://biomage.atlassian.net/browse/BIOMAGE-1969

Changes

Code changes

I have tried to decrease tests variability as much:

• Removing ALL experiments in the testing account before the tests
• before() hook runs before each test case. Test cases should not rely on ordering, so I removed the tests cases and merged them into a single one (because it's very short anyway)
• Replaced samples by smaller ones
• Changed some random stuff that didn't add value
• Added cache to speed up tests a bit.
• Removing all tests is something that happens across the whole env, so now integration tests can't run at the same time in a given environment.
• If a new integration test for a given branch is scheduled, last one is auto-cancelled.

Definition of DONE

Your changes will be ready for merging after each of the steps below have been completed:

Testing

• Unit tests written
• Tested locally with Inframock (with latest production data downloaded with biomage experiment pull)
• Deployed to staging

To set up easy local testing with inframock, follow the instructions here: https://github.com/hms-dbmi-cellenics/inframock
To deploy to the staging environment, follow the instructions here: https://github.com/hms-dbmi-cellenics/biomage-utils

Documentation updates

Is all relevant documentation updated to reflect the proposed changes in this PR?

• Relevant Github READMEs updated
• Relevant wiki pages created/updated

Approvers

• Approved by a member of the core engineering team
• (UX changes) Approved by vickymorrison (this is her username, tag her if you need approval)

Just before merging:

• After the PR is approved, the unstage script in here: https://github.com/hms-dbmi-cellenics/biomage-utils is executed. This script cleans up your deployment to staging

Optional

• Photo of a cute animal attached to this PR