ref: Introduce inline type check for whether a span is StreamedSpan (#6180)

The `isinstance(span, StreamedSpan) and not isinstance(span,
NoOpStreamedSpan)` pattern was repeated in multiple places. Omitting the
`NoOpStreamedSpan` guard is a frequent code review catch — it silently
treats unsampled spans as sampled.

Introduce a more concise type check for proper type narrowing, and
replace all combined-check instances in `scope.py`, `starlette.py`, and
`fastapi.py`.

Locations where `_span` can also be a regular `Span` (not just
`StreamedSpan`) were intentionally left unchanged, as the semantics
differ there.

Fixes PY-2397
Fixes #6182

Author: ericapisani

sentry_sdk/integrations/fastapi.py

@@ -1,19 +1,19 @@
 import sys
 from copy import deepcopy
 from functools import wraps
+from typing import TYPE_CHECKING
 
 import sentry_sdk
 from sentry_sdk.integrations import DidNotEnable
 from sentry_sdk.scope import should_send_default_pii
-from sentry_sdk.traces import NoOpStreamedSpan, StreamedSpan
+from sentry_sdk.traces import StreamedSpan
 from sentry_sdk.tracing import SOURCE_FOR_STYLE, TransactionSource
 from sentry_sdk.tracing_utils import has_span_streaming_enabled
 from sentry_sdk.utils import transaction_from_function
 
-from typing import TYPE_CHECKING
-
 if TYPE_CHECKING:
     from typing import Any, Callable, Dict
+
     from sentry_sdk._types import Event
 
 try:
@@ -95,9 +95,7 @@ def _sentry_call(*args: "Any", **kwargs: "Any") -> "Any":
                 if has_span_streaming_enabled(client.options):
                     current_span = current_scope.streamed_span
 
-                    if isinstance(current_span, StreamedSpan) and not isinstance(
-                        current_span, NoOpStreamedSpan
-                    ):
+                    if type(current_span) is StreamedSpan:
                         segment = current_span._segment
                         segment._update_active_thread()
 

sentry_sdk/integrations/starlette.py

@@ -1,17 +1,18 @@
 import functools
 import json
-import warnings
 import sys
+import warnings
 from collections.abc import Set
 from copy import deepcopy
 from json import JSONDecodeError
+from typing import TYPE_CHECKING
 
 import sentry_sdk
 from sentry_sdk.consts import OP
 from sentry_sdk.integrations import (
+    _DEFAULT_FAILED_REQUEST_STATUS_CODES,
     DidNotEnable,
     Integration,
-    _DEFAULT_FAILED_REQUEST_STATUS_CODES,
 )
 from sentry_sdk.integrations._wsgi_common import (
     DEFAULT_HTTP_METHODS_TO_CAPTURE,
@@ -21,7 +22,8 @@
 )
 from sentry_sdk.integrations.asgi import SentryAsgiMiddleware
 from sentry_sdk.scope import should_send_default_pii
-from sentry_sdk.traces import NoOpStreamedSpan, StreamedSpan, _get_current_streamed_span
+from sentry_sdk.traces import _get_current_streamed_span
+from sentry_sdk.traces import StreamedSpan
 from sentry_sdk.tracing import (
     SOURCE_FOR_STYLE,
     TransactionSource,
@@ -36,8 +38,6 @@
     transaction_from_function,
 )
 
-from typing import TYPE_CHECKING
-
 if TYPE_CHECKING:
     from typing import Any, Awaitable, Callable, Container, Dict, Optional, Tuple, Union
 
@@ -54,7 +54,8 @@
     )
     from starlette.requests import Request  # type: ignore
     from starlette.routing import Match  # type: ignore
-    from starlette.types import ASGIApp, Receive, Scope as StarletteScope, Send  # type: ignore
+    from starlette.types import ASGIApp, Receive, Send  # type: ignore
+    from starlette.types import Scope as StarletteScope
 except ImportError:
     raise DidNotEnable("Starlette is not installed")
 
@@ -255,12 +256,7 @@ def _set_request_body_data_on_streaming_segment(
     info: "Optional[Dict[str, Any]]",
 ) -> None:
     current_span = _get_current_streamed_span()
-    if (
-        info
-        and "data" in info
-        and isinstance(current_span, StreamedSpan)
-        and not isinstance(current_span, NoOpStreamedSpan)
-    ):
+    if info and "data" in info and type(current_span) is StreamedSpan:
         with capture_internal_exceptions():
             current_span._segment.set_attribute(
                 "http.request.body.data",
@@ -557,9 +553,7 @@ def _sentry_sync_func(*args: "Any", **kwargs: "Any") -> "Any":
                 if span_streaming:
                     current_span = current_scope.streamed_span
 
-                    if isinstance(current_span, StreamedSpan) and not isinstance(
-                        current_span, NoOpStreamedSpan
-                    ):
+                    if type(current_span) is StreamedSpan:
                         current_span._segment._update_active_thread()
                 elif current_scope.transaction is not None:
                     current_scope.transaction.update_active_thread()

sentry_sdk/scope.py

@@ -1,13 +1,14 @@
 import os
 import sys
 import warnings
-from copy import copy, deepcopy
 from collections import deque
 from contextlib import contextmanager
-from enum import Enum
+from copy import copy, deepcopy
 from datetime import datetime, timezone
+from enum import Enum
 from functools import wraps
 from itertools import chain
+from typing import TYPE_CHECKING, cast
 
 import sentry_sdk
 from sentry_sdk._types import AnnotatedValue
@@ -18,64 +19,68 @@
     INSTRUMENTER,
     SPANDATA,
 )
-from sentry_sdk.feature_flags import FlagBuffer, DEFAULT_FLAG_CAPACITY
+from sentry_sdk.feature_flags import DEFAULT_FLAG_CAPACITY, FlagBuffer
 from sentry_sdk.profiler.continuous_profiler import (
     get_profiler_id,
     try_autostart_continuous_profiler,
     try_profile_lifecycle_trace_start,
 )
 from sentry_sdk.profiler.transaction_profiler import Profile
 from sentry_sdk.session import Session
-from sentry_sdk.tracing_utils import (
-    Baggage,
-    has_tracing_enabled,
-    has_span_streaming_enabled,
-    is_ignored_span,
-    _make_sampling_decision,
-    PropagationContext,
+from sentry_sdk.traces import (
+    _DEFAULT_PARENT_SPAN,
+    NoOpStreamedSpan,
+    StreamedSpan,
 )
-from sentry_sdk.traces import _DEFAULT_PARENT_SPAN, StreamedSpan, NoOpStreamedSpan
 from sentry_sdk.tracing import (
     BAGGAGE_HEADER_NAME,
     SENTRY_TRACE_HEADER_NAME,
     NoOpSpan,
     Span,
     Transaction,
 )
+from sentry_sdk.tracing_utils import (
+    Baggage,
+    PropagationContext,
+    _make_sampling_decision,
+    has_span_streaming_enabled,
+    has_tracing_enabled,
+    is_ignored_span,
+)
 from sentry_sdk.utils import (
+    ContextVar,
     capture_internal_exception,
     capture_internal_exceptions,
-    ContextVar,
     datetime_from_isoformat,
     disable_capture_event,
     event_from_exception,
     exc_info_from_error,
     format_attribute,
-    logger,
     has_logs_enabled,
     has_metrics_enabled,
+    logger,
 )
 
-from typing import TYPE_CHECKING, cast
-
 if TYPE_CHECKING:
     from collections.abc import Mapping
-
-    from typing import Any
-    from typing import Callable
-    from typing import Deque
-    from typing import Dict
-    from typing import Generator
-    from typing import Iterator
-    from typing import List
-    from typing import Optional
-    from typing import ParamSpec
-    from typing import Tuple
-    from typing import TypeVar
-    from typing import Union
+    from typing import (
+        Any,
+        Callable,
+        Deque,
+        Dict,
+        Generator,
+        Iterator,
+        List,
+        Optional,
+        ParamSpec,
+        Tuple,
+        TypeVar,
+        Union,
+    )
 
     from typing_extensions import Unpack
 
+    import sentry_sdk
     from sentry_sdk._types import (
         Attributes,
         AttributeValue,
@@ -92,11 +97,8 @@
         SamplingContext,
         Type,
     )
-
     from sentry_sdk.tracing import TransactionKwargs
 
-    import sentry_sdk
-
     P = ParamSpec("P")
     R = TypeVar("R")
 
@@ -585,11 +587,7 @@ def get_traceparent(self, *args: "Any", **kwargs: "Any") -> "Optional[str]":
 
         span_streaming = has_span_streaming_enabled(client.options)
         # If we have an active span, return traceparent from there
-        if (
-            span_streaming
-            and self.streamed_span is not None
-            and not isinstance(self.streamed_span, NoOpStreamedSpan)
-        ):
+        if span_streaming and type(self.streamed_span) is StreamedSpan:
             return self.streamed_span._to_traceparent()
         elif not span_streaming and self.span is not None:
             return self.span._to_traceparent()
@@ -609,11 +607,7 @@ def get_baggage(self, *args: "Any", **kwargs: "Any") -> "Optional[Baggage]":
 
         span_streaming = has_span_streaming_enabled(client.options)
         # If we have an active span, return baggage from there
-        if (
-            span_streaming
-            and self.streamed_span is not None
-            and not isinstance(self.streamed_span, NoOpStreamedSpan)
-        ):
+        if span_streaming and type(self.streamed_span) is StreamedSpan:
             return self.streamed_span._to_baggage()
         elif not span_streaming and self.span is not None:
             return self.span._to_baggage()
@@ -918,11 +912,7 @@ def streamed_span(self, span: "Optional[StreamedSpan]") -> None:
 
         # Also set _transaction and _transaction_info in streaming mode as this
         # is used for populating events and linking them to segments
-        if (
-            isinstance(span, StreamedSpan)
-            and not isinstance(span, NoOpStreamedSpan)
-            and span._is_segment()
-        ):
+        if type(span) is StreamedSpan and span._is_segment():
             self._transaction = span.name
             if span._attributes.get("sentry.span.source"):
                 self._transaction_info["source"] = str(

sentry_sdk/traces.py

@@ -31,7 +31,16 @@
 )
 
 if TYPE_CHECKING:
-    from typing import Any, Callable, Iterator, Optional, ParamSpec, TypeVar, Union
+    from typing import (
+        Any,
+        Callable,
+        Iterator,
+        Optional,
+        ParamSpec,
+        TypeVar,
+        Union,
+    )
+
     from sentry_sdk._types import Attributes, AttributeValue
     from sentry_sdk.profiler.continuous_profiler import ContinuousProfile