traceback.format_exception changed in 3.10; use compatible call

Author: chriso

src/dispatch/proto.py

@@ -297,11 +297,15 @@ def _from_proto(cls, proto: call_pb.CallResult) -> CallResult:
         )
 
     @classmethod
-    def from_value(cls, output: Any, correlation_id: Optional[int] = None) -> CallResult:
+    def from_value(
+        cls, output: Any, correlation_id: Optional[int] = None
+    ) -> CallResult:
         return CallResult(correlation_id=correlation_id, output=output)
 
     @classmethod
-    def from_error(cls, error: Error, correlation_id: Optional[int] = None) -> CallResult:
+    def from_error(
+        cls, error: Error, correlation_id: Optional[int] = None
+    ) -> CallResult:
         return CallResult(correlation_id=correlation_id, error=error)
 
 
@@ -352,7 +356,9 @@ def __init__(
         self.value = value
         self.traceback = traceback
         if not traceback and value:
-            self.traceback = "".join(format_exception(value)).encode("utf-8")
+            self.traceback = "".join(
+                format_exception(value.__class__, value, value.__traceback__)
+            ).encode("utf-8")
 
     @classmethod
     def from_exception(cls, ex: Exception, status: Optional[Status] = None) -> Error:

tests/dispatch/test_error.py

@@ -12,7 +12,13 @@ def test_conversion_between_exception_and_error(self):
         except Exception as e:
             original_exception = e
             error = Error.from_exception(e)
-        original_traceback = "".join(traceback.format_exception(original_exception))
+        original_traceback = "".join(
+            traceback.format_exception(
+                original_exception.__class__,
+                original_exception,
+                original_exception.__traceback__,
+            )
+        )
 
         # For some reasons traceback.format_exception does not include the caret
         # (^) in the original traceback, but it does in the reconstructed one,
@@ -24,7 +30,13 @@ def strip_caret(s):
 
         reconstructed_exception = error.to_exception()
         reconstructed_traceback = strip_caret(
-            "".join(traceback.format_exception(reconstructed_exception))
+            "".join(
+                traceback.format_exception(
+                    reconstructed_exception.__class__,
+                    reconstructed_exception,
+                    reconstructed_exception.__traceback__,
+                )
+            )
         )
 
         assert type(reconstructed_exception) is type(original_exception)
@@ -34,7 +46,13 @@ def strip_caret(s):
         error2 = Error.from_exception(reconstructed_exception)
         reconstructed_exception2 = error2.to_exception()
         reconstructed_traceback2 = strip_caret(
-            "".join(traceback.format_exception(reconstructed_exception2))
+            "".join(
+                traceback.format_exception(
+                    reconstructed_exception2.__class__,
+                    reconstructed_exception2,
+                    reconstructed_exception2.__traceback__,
+                )
+            )
         )
 
         assert type(reconstructed_exception2) is type(original_exception)