Unit tests for Firestore run very slow

[SandeepTuniki]

The unit tests for the google-cloud-firestore gem take over 2 minutes, which is very slow during local development.

I timed it on my local machine as shown below:

$ toys ci --no-bundle --test

// ... truncated output

Finished in 136.528543s, 7.0315 runs/s, 39.1420 assertions/s.

Below are the list of slow tests (at-least 1 second), in descending order of run time:

# Output for the command: bundle exec rake test TESTOPTS="-v"

# 6+ seconds
Google::Cloud::Firestore::BulkWriter::mock_firestore::thread tests#test_0002_batch threads tests = 6.05 s = .

# 5+ seconds
Google::Cloud::Firestore::BulkWriter::update::mock_firestore#test_0002_retries a update operation = 5.01 s = .
Google::Cloud::Firestore::BulkWriter::mock_firestore::retry tests#test_0005_retry operations in correct order = 5.01 s = .
Google::Cloud::Firestore::BulkWriter::set::mock_firestore#test_0002_retries a set operation = 5.01 s = .
Google::Cloud::Firestore::BulkWriter::delete::mock_firestore#test_0002_retries a delete operation = 5.00 s = .
Google::Cloud::Firestore::BulkWriter::create::mock_firestore#test_0002_retries a create operation = 5.00 s = .

# 3+ seconds
Google::Cloud::Firestore::CollectionReference::listen::backoff::watch_firestore#test_0006_restarts when GRPC::Unavailable is raised = 3.00 s = .
Google::Cloud::Firestore::CollectionReference::listen::backoff::watch_firestore#test_0004_restarts when GRPC::ResourceExhausted is raised = 3.01 s = .
Google::Cloud::Firestore::CollectionReference::listen::backoff::watch_firestore#test_0002_restarts when GRPC::DeadlineExceeded is raised = 3.01 s = .
Google::Cloud::Firestore::CollectionReference::listen::watch_firestore#test_0006_invokes on_error callbacks when the listener receives errors = 3.00 s = .
Google::Cloud::Firestore::DocumentReference::listen::watch_firestore#test_0004_invokes on_error callbacks when the listener receives errors = 3.00 s = .
Google::Cloud::Firestore::CollectionReference::listen::watch_firestore#test_0005_resets when FILTER count is incorrect = 3.01 s = .
Google::Cloud::Firestore::DocumentReference::listen::watch_firestore#test_0003_resets when FILTER count is incorrect = 3.00 s = .
Google::Cloud::Firestore::DocumentReference::listen::retry::watch_firestore#test_0006_restarts when GRPC::Unavailable is raised = 3.00 s = .
Google::Cloud::Firestore::DocumentReference::listen::retry::watch_firestore#test_0002_restarts when GRPC::DeadlineExceeded is raised = 3.00 s = .
Google::Cloud::Firestore::DocumentReference::listen::retry::watch_firestore#test_0004_restarts when GRPC::ResourceExhausted is raised = 3.00 s = .
ConformanceListen#test_/...[truncated_path].../conformance/v1/listen-doc-remove.json: listen: DocumentRemove behaves like DocumentDelete = 3.00 s = .
ConformanceListen#test_/...[truncated_path].../conformance/v1/listen-add-three.json: listen: add three documents = 3.00 s = .
ConformanceListen#test_/...[truncated_path].../conformance/v1/listen-nomod.json: listen: add a doc, then change it but without changing its update time = 3.00 s = .
ConformanceListen#test_/...[truncated_path].../conformance/v1/listen-add-mod-del-add.json: listen: add a doc, modify it, delete it, then add it again = 3.00 s = .
ConformanceListen#test_/...[truncated_path].../conformance/v1/listen-removed-target-ids.json: listen: DocumentChange with removed_target_id is like a delete. = 3.00 s = .
ConformanceListen#test_/...[truncated_path].../conformance/v1/listen-filter-nop.json: listen: Filter response with same size is a no-op = 3.00 s = .
ConformanceListen#test_/...[truncated_path].../conformance/v1/listen-empty.json: listen: no changes; empty snapshot = 3.00 s = .

# 2+ seconds
Google::Cloud::Firestore::CollectionReference::listen::backoff::watch_firestore#test_0003_restarts when GRPC::Internal is raised = 2.00 s = .
Google::Cloud::Firestore::CollectionReference::listen::backoff::watch_firestore#test_0007_restarts when GRPC::Unknown is raised = 2.00 s = .
Google::Cloud::Firestore::CollectionReference::listen::backoff::watch_firestore#test_0005_restarts when GRPC::Unauthenticated is raised = 2.00 s = .
Google::Cloud::Firestore::CollectionReference::listen::watch_firestore#test_0003_listens to a query and yields query snapshots = 2.00 s = .
Google::Cloud::Firestore::CollectionReference::listen::watch_firestore#test_0004_resets when RESET is returned = 2.00 s = .
Google::Cloud::Firestore::CollectionReference::listen::watch_firestore#test_0002_listens to a limit_to_last query = 2.00 s = .
Google::Cloud::Firestore::RateLimiter#test_0002_checks whether the bandwidth increases after phase length = 2.00 s = .
Google::Cloud::Firestore::DocumentReference::listen::watch_firestore#test_0002_resets when RESET is returned = 2.00 s = .
Google::Cloud::Firestore::DocumentReference::listen::retry::watch_firestore#test_0003_restarts when GRPC::Internal is raised = 2.00 s = .
Google::Cloud::Firestore::DocumentReference::listen::retry::watch_firestore#test_0007_restarts when GRPC::Unknown is raised = 2.00 s = .
Google::Cloud::Firestore::DocumentReference::listen::retry::watch_firestore#test_0005_restarts when GRPC::Unauthenticated is raised = 2.00 s = .
ConformanceListen#test_/...[truncated_path].../conformance/v1/listen-target-add-nop.json: listen: TargetChange_ADD is a no-op if it has the same target ID = 2.00 s = .
ConformanceListen#test_/...[truncated_path].../conformance/v1/listen-reset.json: listen: RESET turns off CURRENT = 2.00 s = .
ConformanceListen#test_/...[truncated_path].../conformance/v1/listen-multi-docs.json: listen: multiple documents, added, deleted and updated = 2.00 s = .
ConformanceListen#test_/...[truncated_path].../conformance/v1/listen-add-one.json: listen: add a doc = 2.00 s = .
ConformanceListen#test_/...[truncated_path].../conformance/v1/listen-nocurrent.json: listen: no snapshot if we don't see CURRENT = 2.00 s = .

# 1+ second
Google::Cloud::Firestore::BulkWriter::mock_firestore::retry tests#test_0004_retry only the failed operation of a batch = 1.01 s = .
Google::Cloud::Firestore::BulkWriter::mock_firestore::retry tests#test_0003_retry operations only after retry time = 1.10 s = .
Google::Cloud::Firestore::Promise::Future::mock_firestore#test_0004_correctly returns the rejected reason = 1.20 s = .
Google::Cloud::Firestore::Promise::Future::mock_firestore#test_0006_successfully adds callback on rejection = 1.01 s = .
Google::Cloud::Firestore::BulkWriter::mock_firestore#test_0005_marks operation complete in case of BulkWriterOperationError when mutation was failure = 1.01 s = .