From 4c0aefb6296c3186b3a878fd32073fe1e9ba7c0e Mon Sep 17 00:00:00 2001
From: David Fernandez <david@lifeready.io>
Date: Thu, 25 Nov 2021 11:59:04 +1100
Subject: [PATCH 1/2] Added optional scrubber for transaction events, mirroring
 before_send for events.

---
 sentry_sdk/client.py | 13 +++++++++++++
 sentry_sdk/consts.py |  1 +
 2 files changed, 14 insertions(+)

diff --git a/sentry_sdk/client.py b/sentry_sdk/client.py
index 67ed94cc38..aefd8122a1 100644
--- a/sentry_sdk/client.py
+++ b/sentry_sdk/client.py
@@ -194,6 +194,19 @@ def _prepare_event(
                 ),
             )
 
+        before_send_transaction = self.options["before_send_transaction"]
+        if before_send_transaction is not None and event.get("type") == "transaction":
+            new_event = None
+            with capture_internal_exceptions():
+                new_event = before_send_transaction(event, hint or {})
+            if new_event is None:
+                logger.info("before send transaction dropped event (%s)", event)
+                if self.transport:
+                    self.transport.record_lost_event(
+                        "before_send_transaction", data_category="error"
+                    )
+            event = new_event  # type: ignore
+
         before_send = self.options["before_send"]
         if before_send is not None and event.get("type") != "transaction":
             new_event = None
diff --git a/sentry_sdk/consts.py b/sentry_sdk/consts.py
index 0f7675fbcd..7c20f61fb2 100644
--- a/sentry_sdk/consts.py
+++ b/sentry_sdk/consts.py
@@ -67,6 +67,7 @@ def __init__(
         ignore_errors=[],  # type: List[Union[type, str]]  # noqa: B006
         request_bodies="medium",  # type: str
         before_send=None,  # type: Optional[EventProcessor]
+        before_send_transaction=None,  # type: Optional[EventProcessor]
         before_breadcrumb=None,  # type: Optional[BreadcrumbProcessor]
         debug=False,  # type: bool
         attach_stacktrace=False,  # type: bool

From 40bc58539c5ac3e4a79a449c16dba521018ee3c0 Mon Sep 17 00:00:00 2001
From: David Fernandez <david@lifeready.io>
Date: Thu, 25 Nov 2021 12:19:11 +1100
Subject: [PATCH 2/2] Added early return to avoid subsequent error with
 dropped/None event.

---
 sentry_sdk/client.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/sentry_sdk/client.py b/sentry_sdk/client.py
index aefd8122a1..155c4a0699 100644
--- a/sentry_sdk/client.py
+++ b/sentry_sdk/client.py
@@ -205,6 +205,7 @@ def _prepare_event(
                     self.transport.record_lost_event(
                         "before_send_transaction", data_category="error"
                     )
+                return None
             event = new_event  # type: ignore
 
         before_send = self.options["before_send"]