From 8a67dc768ccf5a8adea41af11d975b3a7683a1e1 Mon Sep 17 00:00:00 2001
From: Zac Hatfield-Dodds <zac.hatfield.dodds@gmail.com>
Date: Sun, 26 Nov 2023 23:12:09 -0800
Subject: [PATCH] refactor interesting_origin

---
 hypothesis-python/src/hypothesis/core.py      |  4 +-
 .../src/hypothesis/internal/escalation.py     | 53 ++++++++++++-------
 .../tests/cover/test_escalation.py            | 20 ++++++-
 3 files changed, 55 insertions(+), 22 deletions(-)

diff --git a/hypothesis-python/src/hypothesis/core.py b/hypothesis-python/src/hypothesis/core.py
index 1c4cf9e144..723e3da646 100644
--- a/hypothesis-python/src/hypothesis/core.py
+++ b/hypothesis-python/src/hypothesis/core.py
@@ -80,10 +80,10 @@
 from hypothesis.internal.conjecture.shrinker import sort_key
 from hypothesis.internal.entropy import deterministic_PRNG
 from hypothesis.internal.escalation import (
+    InterestingOrigin,
     current_pytest_item,
     escalate_hypothesis_internal_error,
     format_exception,
-    get_interesting_origin,
     get_trimmed_traceback,
 )
 from hypothesis.internal.healthcheck import fail_health_check
@@ -970,7 +970,7 @@ def _execute_once_for_engine(self, data):
 
                 self.failed_normally = True
 
-                interesting_origin = get_interesting_origin(e)
+                interesting_origin = InterestingOrigin.from_exception(e)
                 if trace:  # pragma: no cover
                     # Trace collection is explicitly disabled under coverage.
                     self.explain_traces[interesting_origin].add(trace)
diff --git a/hypothesis-python/src/hypothesis/internal/escalation.py b/hypothesis-python/src/hypothesis/internal/escalation.py
index 605ea52e97..24015e691e 100644
--- a/hypothesis-python/src/hypothesis/internal/escalation.py
+++ b/hypothesis-python/src/hypothesis/internal/escalation.py
@@ -11,10 +11,11 @@
 import contextlib
 import os
 import sys
+import textwrap
 import traceback
 from inspect import getframeinfo
 from pathlib import Path
-from typing import Dict
+from typing import Dict, NamedTuple, Type
 
 import hypothesis
 from hypothesis.errors import (
@@ -105,32 +106,46 @@ def get_trimmed_traceback(exception=None):
     return tb
 
 
-def get_interesting_origin(exception):
+class InterestingOrigin(NamedTuple):
     # The `interesting_origin` is how Hypothesis distinguishes between multiple
     # failures, for reporting and also to replay from the example database (even
     # if report_multiple_bugs=False).  We traditionally use the exception type and
     # location, but have extracted this logic in order to see through `except ...:`
     # blocks and understand the __cause__ (`raise x from y`) or __context__ that
     # first raised an exception as well as PEP-654 exception groups.
-    tb = get_trimmed_traceback(exception)
-    if tb is None:
+    exc_type: Type[BaseException]
+    filename: str
+    lineno: int
+    context: "InterestingOrigin | tuple[()]"
+    group_elems: "tuple[InterestingOrigin, ...]"
+
+    def __str__(self) -> str:
+        ctx = ""
+        if self.context:
+            ctx = textwrap.indent(f"\ncontext: {self.context}", prefix="    ")
+        group = ""
+        if self.group_elems:
+            chunks = "\n  ".join(str(x) for x in self.group_elems)
+            group = textwrap.indent(f"\nchild exceptions:\n  {chunks}", prefix="    ")
+        return f"{self.exc_type.__name__} at {self.filename}:{self.lineno}{ctx}{group}"
+
+    @classmethod
+    def from_exception(cls, exception: BaseException, /) -> "InterestingOrigin":
         filename, lineno = None, None
-    else:
-        filename, lineno, *_ = traceback.extract_tb(tb)[-1]
-    return (
-        type(exception),
-        filename,
-        lineno,
-        # Note that if __cause__ is set it is always equal to __context__, explicitly
-        # to support introspection when debugging, so we can use that unconditionally.
-        get_interesting_origin(exception.__context__) if exception.__context__ else (),
-        # We distinguish exception groups by the inner exceptions, as for __context__
-        tuple(
-            map(get_interesting_origin, exception.exceptions)
+        if tb := get_trimmed_traceback(exception):
+            filename, lineno, *_ = traceback.extract_tb(tb)[-1]
+        return cls(
+            type(exception),
+            filename,
+            lineno,
+            # Note that if __cause__ is set it is always equal to __context__, explicitly
+            # to support introspection when debugging, so we can use that unconditionally.
+            cls.from_exception(exception.__context__) if exception.__context__ else (),
+            # We distinguish exception groups by the inner exceptions, as for __context__
+            tuple(map(cls.from_exception, exception.exceptions))
             if isinstance(exception, BaseExceptionGroup)
-            else []
-        ),
-    )
+            else (),
+        )
 
 
 current_pytest_item = DynamicVariable(None)
diff --git a/hypothesis-python/tests/cover/test_escalation.py b/hypothesis-python/tests/cover/test_escalation.py
index 212f462c51..2a176403f3 100644
--- a/hypothesis-python/tests/cover/test_escalation.py
+++ b/hypothesis-python/tests/cover/test_escalation.py
@@ -78,4 +78,22 @@ def test_errors_attribute_error():
 
 
 def test_handles_null_traceback():
-    esc.get_interesting_origin(Exception())
+    esc.InterestingOrigin.from_exception(Exception())
+
+
+def test_handles_context():
+    e = ValueError()
+    e.__context__ = KeyError()
+    origin = esc.InterestingOrigin.from_exception(e)
+    assert "ValueError at " in str(origin)
+    assert "  context: " in str(origin)
+    assert "KeyError at " in str(origin)
+
+
+def test_handles_groups():
+    origin = esc.InterestingOrigin.from_exception(
+        BaseExceptionGroup("message", [ValueError("msg2")])
+    )
+    assert "ExceptionGroup at " in str(origin)
+    assert "child exception" in str(origin)
+    assert "ValueError at " in str(origin)