Extract additional expression values with pure_eval (#762)

Author: alexmojaki

mypy.ini

@@ -50,3 +50,7 @@ ignore_missing_imports = True
 ignore_missing_imports = True
 [mypy-executing.*]
 ignore_missing_imports = True
+[mypy-asttokens.*]
+ignore_missing_imports = True
+[mypy-pure_eval.*]
+ignore_missing_imports = True

sentry_sdk/integrations/pure_eval.py

@@ -0,0 +1,104 @@
+from __future__ import absolute_import
+
+import ast
+
+from sentry_sdk import Hub
+from sentry_sdk._types import MYPY
+from sentry_sdk.integrations import Integration, DidNotEnable
+from sentry_sdk.scope import add_global_event_processor
+from sentry_sdk.utils import walk_exception_chain, iter_stacks
+
+if MYPY:
+    from typing import Optional, Dict, Any
+    from types import FrameType
+
+    from sentry_sdk._types import Event, Hint
+
+try:
+    import executing
+except ImportError:
+    raise DidNotEnable("executing is not installed")
+
+try:
+    import pure_eval
+except ImportError:
+    raise DidNotEnable("pure_eval is not installed")
+
+try:
+    # Used implicitly, just testing it's available
+    import asttokens  # noqa
+except ImportError:
+    raise DidNotEnable("asttokens is not installed")
+
+
+class PureEvalIntegration(Integration):
+    identifier = "pure_eval"
+
+    @staticmethod
+    def setup_once():
+        # type: () -> None
+
+        @add_global_event_processor
+        def add_executing_info(event, hint):
+            # type: (Event, Optional[Hint]) -> Optional[Event]
+            if Hub.current.get_integration(PureEvalIntegration) is None:
+                return event
+
+            if hint is None:
+                return event
+
+            exc_info = hint.get("exc_info", None)
+
+            if exc_info is None:
+                return event
+
+            exception = event.get("exception", None)
+
+            if exception is None:
+                return event
+
+            values = exception.get("values", None)
+
+            if values is None:
+                return event
+
+            for exception, (_exc_type, _exc_value, exc_tb) in zip(
+                reversed(values), walk_exception_chain(exc_info)
+            ):
+                sentry_frames = [
+                    frame
+                    for frame in exception.get("stacktrace", {}).get("frames", [])
+                    if frame.get("function")
+                ]
+                tbs = list(iter_stacks(exc_tb))
+                if len(sentry_frames) != len(tbs):
+                    continue
+
+                for sentry_frame, tb in zip(sentry_frames, tbs):
+                    sentry_frame["vars"].update(pure_eval_frame(tb.tb_frame))
+            return event
+
+
+def pure_eval_frame(frame):
+    # type: (FrameType) -> Dict[str, Any]
+    source = executing.Source.for_frame(frame)
+    if not source.tree:
+        return {}
+
+    statements = source.statements_at_line(frame.f_lineno)
+    if not statements:
+        return {}
+
+    stmt = list(statements)[0]
+    while True:
+        # Get the parent first in case the original statement is already
+        # a function definition, e.g. if we're calling a decorator
+        # In that case we still want the surrounding scope, not that function
+        stmt = stmt.parent
+        if isinstance(stmt, (ast.FunctionDef, ast.ClassDef, ast.Module)):
+            break
+
+    evaluator = pure_eval.Evaluator.from_frame(frame)
+    expressions = evaluator.interesting_expressions_grouped(stmt)
+    atok = source.asttokens()
+    return {atok.get_text(nodes[0]): value for nodes, value in expressions}

test-requirements.txt

@@ -8,3 +8,4 @@ gevent
 eventlet
 newrelic
 executing
+asttokens

tests/integrations/pure_eval/__init__.py

@@ -0,0 +1,3 @@
+import pytest
+
+pure_eval = pytest.importorskip("pure_eval")

tests/integrations/pure_eval/test_pure_eval.py

@@ -0,0 +1,35 @@
+import pytest
+
+from sentry_sdk import capture_exception
+from sentry_sdk.integrations.pure_eval import PureEvalIntegration
+
+
+@pytest.mark.parametrize("integrations", [[], [PureEvalIntegration()]])
+def test_with_locals_enabled(sentry_init, capture_events, integrations):
+    sentry_init(with_locals=True, integrations=integrations)
+    events = capture_events()
+
+    def foo():
+        foo.d = {1: 2}
+        print(foo.d[1] / 0)
+
+    try:
+        foo()
+    except Exception:
+        capture_exception()
+
+    (event,) = events
+
+    assert all(
+        frame["vars"]
+        for frame in event["exception"]["values"][0]["stacktrace"]["frames"]
+    )
+
+    frame_vars = event["exception"]["values"][0]["stacktrace"]["frames"][-1]["vars"]
+
+    if integrations:
+        assert sorted(frame_vars.keys()) == ["foo", "foo.d", "foo.d[1]"]
+        assert frame_vars["foo.d"] == {"1": "2"}
+        assert frame_vars["foo.d[1]"] == "2"
+    else:
+        assert sorted(frame_vars.keys()) == ["foo"]

tox.ini

@@ -73,6 +73,8 @@ envlist =
 [testenv]
 deps =
     -r test-requirements.txt
+    
+    py3.{5,6,7,8}: pure_eval
 
     django-{1.11,2.0,2.1,2.2,3.0,dev}: djangorestframework>=3.0.0,<4.0.0
     {py3.7,py3.8}-django-{1.11,2.0,2.1,2.2,3.0,dev}: channels>2