feat(scope): Emit buffer_overflow discard reason when popping breadcrumbs

[AbhiPrasad]

ref getsentry/team-sdks#116

This PR implements a new client discard reason for buffer_overflow. This will be used to track when the internal breadcrumbs buffer overflows for the new logs product that we are working on.

log_item is the new data category for logs, which we are basing out of breadcrumbs. Eventually we will be sending standalone envelope items that only contain breadcrumbs.

[codecov]

❌ 3 Tests Failed:

Tests completed	Failed	Passed	Skipped
22080	3	22077	5708

View the top 3 failed tests by shortest run time

tests.integrations.aiohttp.test_aiohttp test_crumb_capture

Stack Traces | 0.002s run time

file .../integrations/aiohttp/test_aiohttp.py, line 476
  @pytest.mark.asyncio
  async def test_crumb_capture(
      sentry_init, aiohttp_raw_server, aiohttp_client, loop, capture_events
  ):
      def before_breadcrumb(crumb, hint):
E       fixture 'loop' not found
>       available fixtures: DictionaryContaining, ObjectDescribedBy, StringContaining, _capture_internal_warnings, _session_event_loop, aiohttp_client, aiohttp_client_cls, aiohttp_raw_server, aiohttp_server, benchmark, cache, capfd, capfdbinary, caplog, capsys, capsysbinary, capture_envelopes, capture_events, capture_events_forksafe, capture_exceptions, capture_record_lost_event_calls, clean_scopes, cov, doctest_namespace, event_loop, event_loop_policy, httpserver, httpsserver, internal_exceptions, maybe_monkeypatched_threading, monkeypatch, no_cover, pytestconfig, record_property, record_testsuite_property, record_xml_attribute, recwarn, render_span_tree, reset_integrations, sentry_init, smtpserver, suppress_deprecation_warnings, teardown_profiling, .../integrations/aiohttp/test_aiohttp.py::<event_loop>, tests/integrations/aiohttp::<event_loop>, tmp_path, tmp_path_factory, tmpdir, tmpdir_factory, uninstall_integration, unused_tcp_port, unused_tcp_port_factory, unused_udp_port, unused_udp_port_factory, validate_event_schema
>       use 'pytest --fixtures [testpath]' for help on them.

.../integrations/aiohttp/test_aiohttp.py:476

tests.integrations.aiohttp.test_aiohttp test_crumb_capture

Stack Traces | 0.002s run time

file .../integrations/aiohttp/test_aiohttp.py, line 476
  @pytest.mark.asyncio
  async def test_crumb_capture(
      sentry_init, aiohttp_raw_server, aiohttp_client, loop, capture_events
  ):
      def before_breadcrumb(crumb, hint):
E       fixture 'loop' not found
>       available fixtures: DictionaryContaining, ObjectDescribedBy, StringContaining, _capture_internal_warnings, _session_event_loop, aiohttp_client, aiohttp_client_cls, aiohttp_raw_server, aiohttp_server, benchmark, cache, capfd, capfdbinary, caplog, capsys, capsysbinary, capture_envelopes, capture_events, capture_events_forksafe, capture_exceptions, capture_record_lost_event_calls, clean_scopes, cov, doctest_namespace, event_loop, event_loop_policy, httpserver, httpsserver, internal_exceptions, maybe_monkeypatched_threading, monkeypatch, no_cover, pytestconfig, record_property, record_testsuite_property, record_xml_attribute, recwarn, render_span_tree, reset_integrations, sentry_init, smtpserver, suppress_deprecation_warnings, teardown_profiling, .../integrations/aiohttp/test_aiohttp.py::<event_loop>, tests/integrations/aiohttp::<event_loop>, tmp_path, tmp_path_factory, tmpdir, tmpdir_factory, uninstall_integration, unused_tcp_port, unused_tcp_port_factory, unused_udp_port, unused_udp_port_factory, validate_event_schema
>       use 'pytest --fixtures [testpath]' for help on them.

.../integrations/aiohttp/test_aiohttp.py:476

tests.integrations.stdlib.test_httplib test_http_timeout

Stack Traces | 0.263s run time

.../integrations/stdlib/test_httplib.py:373: in test_http_timeout
    assert len(transaction["spans"]) == 1
E   assert 0 == 1
E     +0
E     -1

To view more test analytics, go to the Test Analytics Dashboard
📢 Thoughts on this report? Let us know!

[sentrivana]

@AbhiPrasad The change looks good to me but we should have a test for this.

I imagine we can come up with a test case by combining some of the client report tests in https://github.com/getsentry/sentry-python/blob/master/tests/test_transport.py and this max_breadcrumbs test.

Do you have some bandwidth to look into adding a test case? Otherwise I can try coming up with something.