Extract additional expression values with pure_eval

sentry_sdk/utils.py

@@ -1,3 +1,4 @@
+import ast
 import os
 import sys
 import linecache
@@ -27,8 +28,22 @@
 
     from sentry_sdk._types import ExcInfo, EndpointType
 
-epoch = datetime(1970, 1, 1)
+try:
+    import executing
+except ImportError:
+    executing = None
+
+try:
+    import asttokens
+except ImportError:
+    asttokens = None
 
+try:
+    import pure_eval
+except ImportError:
+    pure_eval = None
+
+epoch = datetime(1970, 1, 1)
 
 # The logger is created here but initialized in the debug support module
 logger = logging.getLogger("sentry_sdk.errors")
@@ -453,11 +468,39 @@ def serialize_frame(frame, tb_lineno=None, with_locals=True):
         "post_context": post_context,
     }  # type: Dict[str, Any]
     if with_locals:
-        rv["vars"] = frame.f_locals
+        rv["vars"] = pure_eval_frame(frame)
+        rv["vars"].update(frame.f_locals)
 
     return rv
 
 
+def pure_eval_frame(frame):
+    if not (executing and pure_eval and asttokens):
+        return {}
+
+    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}
+
+
 def stacktrace_from_traceback(tb=None, with_locals=True):
     # type: (Optional[TracebackType], bool) -> Dict[str, List[Dict[str, Any]]]
     return {

test-requirements.txt

@@ -7,3 +7,6 @@ pytest-cov==2.8.1
 gevent
 eventlet
 newrelic
+executing
+pure_eval
+asttokens

tests/test_client.py

@@ -180,8 +180,13 @@ def e(exc):
 def test_with_locals_enabled():
     events = []
     hub = Hub(Client(with_locals=True, transport=events.append))
+
+    def foo():
+        foo.d = {1: 2}
+        print(foo.d[1] / 0)
+
     try:
-        1 / 0
+        foo()
     except Exception:
         hub.capture_exception()
 
@@ -192,6 +197,11 @@ def test_with_locals_enabled():
         for frame in event["exception"]["values"][0]["stacktrace"]["frames"]
     )
 
+    frame_vars = event["exception"]["values"][0]["stacktrace"]["frames"][-1]["vars"]
+    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"
+
 
 def test_with_locals_disabled():
     events = []