Observe backend in how_generated

hypothesis-python/RELEASE.rst

@@ -0,0 +1,4 @@
+RELEASE_TYPE: patch
+
+This patch includes the :obj:`~hypothesis.settings.backend` setting in the
+``how_generated`` field of our :doc:`observability output <observability>`.

hypothesis-python/src/hypothesis/core.py

@@ -786,7 +786,6 @@ def __init__(self, stuff, test, settings, random, wrapped_test):
         self.explain_traces = defaultdict(set)
         self._start_timestamp = time.time()
         self._string_repr = ""
-        self._jsonable_arguments = {}
         self._timing_features = {}
 
     @property
@@ -913,7 +912,7 @@ def run(data):
                     ),
                 )
                 self._string_repr = printer.getvalue()
-                self._jsonable_arguments = {
+                data._observability_arguments = {
                     **dict(enumerate(map(to_jsonable, args))),
                     **{k: to_jsonable(v) for k, v in kwargs.items()},
                 }
@@ -1085,19 +1084,23 @@ def _execute_once_for_engine(self, data: ConjectureData) -> None:
             # Conditional here so we can save some time constructing the payload; in
             # other cases (without coverage) it's cheap enough to do that regardless.
             if TESTCASE_CALLBACKS:
-                if self.failed_normally or self.failed_due_to_deadline:
-                    phase = "shrink"
-                elif runner := getattr(self, "_runner", None):
+                if runner := getattr(self, "_runner", None):
                     phase = runner._current_phase
+                elif self.failed_normally or self.failed_due_to_deadline:
+                    phase = "shrink"
                 else:  # pragma: no cover  # in case of messing with internals
                     phase = "unknown"
+                backend_desc = f", using backend={self.settings.backend!r}" * (
+                    self.settings.backend != "hypothesis"
+                    and not getattr(runner, "_switch_to_hypothesis_provider", False)
+                )
                 tc = make_testcase(
                     start_timestamp=self._start_timestamp,
                     test_name_or_nodeid=self.test_identifier,
                     data=data,
-                    how_generated=f"generated during {phase} phase",
+                    how_generated=f"during {phase} phase{backend_desc}",
                     string_repr=self._string_repr,
-                    arguments={**self._jsonable_arguments, **data._observability_args},
+                    arguments=data._observability_args,
                     timing=self._timing_features,
                     coverage=tractable_coverage_report(trace) or None,
                     phase=phase,
@@ -1217,7 +1220,7 @@ def run_engine(self):
                     "status": "passed" if sys.exc_info()[0] else "failed",
                     "status_reason": str(origin or "unexpected/flaky pass"),
                     "representation": self._string_repr,
-                    "arguments": self._jsonable_arguments,
+                    "arguments": ran_example._observability_args,
                     "how_generated": "minimal failing example",
                     "features": {
                         **{

hypothesis-python/src/hypothesis/internal/observability.py

@@ -36,7 +36,7 @@ def make_testcase(
     start_timestamp: float,
     test_name_or_nodeid: str,
     data: ConjectureData,
-    how_generated: str = "unknown",
+    how_generated: str,
     string_repr: str = "<unknown>",
     arguments: Optional[dict] = None,
     timing: Dict[str, float],