sample rspec expectations and stubs

## IMPORTANT -> The expectation must come before the invocation, so that it can catch the invocation when it happens

# Able to stub an instance's method. Will return whatever is in the block. The instance's method would have to be invoked in the RSpec.
@person.stub(:get_relevant_experts) { @collection_of_possibilities }

# Expectation of an instance that is available in the testing context to receive a particular method, choose return value
expect(@person).to receive(:get_relevant_experts).with("Medical").and_return(@collection_of_possibilities)

# Expectation of an instance to receive a method and return a result
expect_any_instance_of(Classification).to receive(:valid_matches).and_return(@collection_of_possibilities)

# Expectation of a class to receive a method
expect(ClassificationSystem).to receive(:choose_record_with_special_flag_or_unclassified_fallback)

# How to stub a constant within a class
stub_const("Api::V1::PublicationsController::DEFAULT_PAGINATION_COUNT", 1)

Incase you see other specs that break intermittently...

It has a decently high likelihood to be due to:

1. expecting that AR will automatically return records in order of id (self.survey_results .vs. self.survey_results.order(:id))
2. DateTime objects needing to be stubbed properly
3. ENV variables getting set in a spec, then specs after are adversely affected (eg. settings.yml values, Rails.env, or other initializer values)