fix: Dont crash on breadcrumb overflow (#70)

Fix #67

Author: untitaker

sentry_sdk/hub.py

@@ -205,8 +205,8 @@ def add_breadcrumb(self, crumb=None, hint=None, **kwargs):
             scope._breadcrumbs.append(crumb)
         else:
             logger.info("before breadcrumb dropped breadcrumb (%s)", original_crumb)
-        while len(scope._breadcrumbs) >= client.options["max_breadcrumbs"]:
-            scope._breadcrumbs.popleft()
+        while len(scope._breadcrumbs) > client.options["max_breadcrumbs"]:
+            scope._breadcrumbs.pop(0)
 
     def push_scope(self, callback=None):
         """Pushes a new layer on the scope stack. Returns a context manager

tests/test_basics.py

@@ -139,3 +139,20 @@ def test_push_scope_null_client(sentry_init, capture_events):
             capture_exception(e)
 
     assert len(events) == 0
+
+
+def test_breadcrumbs_overflow(sentry_init, capture_events):
+    sentry_init(max_breadcrumbs=10)
+
+    for i in range(20):
+        add_breadcrumb(
+            category="auth", message="Authenticated user %s" % i, level="info"
+        )
+
+    events = capture_events()
+
+    capture_exception(ValueError())
+
+    event, = events
+
+    assert len(event["breadcrumbs"]) == 10