feat(workflow_engine): Add in hook for producing occurrences from the stateful detector

[ShashankFC]

Test 10

Summary by CodeRabbit

• Refactor
  • Restructured metric alert detection system to use group-based result tracking instead of list-based aggregation.
  • Enhanced detector evaluation framework with improved state management and occurrence data handling.

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---

Replicated from ai-code-review-evaluation/sentry-coderabbit#10

[ShashankFC]

@cubic-dev-ai review this pull request

[cubic-dev-ai]

@cubic-dev-ai review this pull request

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[cubic-dev-ai]

3 issues found across 4 files

Prompt for AI agents (all issues)

Check if these issues are valid — if so, understand the root cause of each and fix them.


<file name="tests/sentry/workflow_engine/processors/test_detector.py">

<violation number="1" location="tests/sentry/workflow_engine/processors/test_detector.py:150">
P1: Bug: occurrence is built with group_key `"val1"` but the expected result uses group_key `"group_key"`. The fingerprints will differ, causing a test assertion mismatch. Should use `"group_key"` as the group_key for the mock occurrence.</violation>
</file>

<file name="src/sentry/workflow_engine/processors/detector.py">

<violation number="1" location="src/sentry/workflow_engine/processors/detector.py:128">
P3: Docstring is now stale: it says "returns a list of `DetectorEvaluationResult`" but the return type was changed to `dict[DetectorGroupKey, DetectorEvaluationResult]`. Update the docstring to reflect the new return type.</violation>
</file>

<file name="src/sentry/incidents/grouptype.py">

<violation number="1" location="src/sentry/incidents/grouptype.py:11">
P2: `MetricAlertDetectorHandler` inherits from `StatefulDetectorHandler` (which is abstract) but does not implement any of its 4 required abstract methods (`counter_names`, `get_dedupe_value`, `get_group_key_values`, `build_occurrence_and_event_data`). This class cannot be instantiated — Python will raise `TypeError` at runtime. If this is intentional as a WIP, consider keeping it explicitly abstract (e.g., add `abc.ABC` to the class or add a comment clarifying it's not intended to be instantiated yet).</violation>
</file>

_{Reply with feedback, questions, or to request a fix. Tag @cubic-dev-ai to re-run a review.}

[cubic-dev-ai]

P1: Bug: occurrence is built with group_key "val1" but the expected result uses group_key "group_key". The fingerprints will differ, causing a test assertion mismatch. Should use "group_key" as the group_key for the mock occurrence.

Prompt for AI agents

Check if this issue is valid — if so, understand the root cause and fix it. At tests/sentry/workflow_engine/processors/test_detector.py, line 150:

<comment>Bug: occurrence is built with group_key `"val1"` but the expected result uses group_key `"group_key"`. The fingerprints will differ, causing a test assertion mismatch. Should use `"group_key"` as the group_key for the mock occurrence.</comment>

<file context>
@@ -73,64 +138,88 @@ def test(self):
+        detector = self.create_detector_and_conditions(type=self.handler_state_type.slug)
+        data_packet = DataPacket("1", {"dedupe": 2, "group_vals": {None: 6}})
         results = process_detectors(data_packet, [detector])
+        occurrence, event_data = build_mock_occurrence_and_event(
+            detector.detector_handler, None, 6, PriorityLevel.HIGH
+        )
</file context>

[cubic-dev-ai]

P2: MetricAlertDetectorHandler inherits from StatefulDetectorHandler (which is abstract) but does not implement any of its 4 required abstract methods (counter_names, get_dedupe_value, get_group_key_values, build_occurrence_and_event_data). This class cannot be instantiated — Python will raise TypeError at runtime. If this is intentional as a WIP, consider keeping it explicitly abstract (e.g., add abc.ABC to the class or add a comment clarifying it's not intended to be instantiated yet).

Prompt for AI agents

Check if this issue is valid — if so, understand the root cause and fix it. At src/sentry/incidents/grouptype.py, line 11:

<comment>`MetricAlertDetectorHandler` inherits from `StatefulDetectorHandler` (which is abstract) but does not implement any of its 4 required abstract methods (`counter_names`, `get_dedupe_value`, `get_group_key_values`, `build_occurrence_and_event_data`). This class cannot be instantiated — Python will raise `TypeError` at runtime. If this is intentional as a WIP, consider keeping it explicitly abstract (e.g., add `abc.ABC` to the class or add a comment clarifying it's not intended to be instantiated yet).</comment>

<file context>
@@ -4,17 +4,12 @@
-    ) -> list[DetectorEvaluationResult]:
-        # TODO: Implement
-        return []
+class MetricAlertDetectorHandler(StatefulDetectorHandler[QuerySubscriptionUpdate]):
+    pass
 
</file context>

[cubic-dev-ai]

P3: Docstring is now stale: it says "returns a list of DetectorEvaluationResult" but the return type was changed to dict[DetectorGroupKey, DetectorEvaluationResult]. Update the docstring to reflect the new return type.

Prompt for AI agents

Check if this issue is valid — if so, understand the root cause and fix it. At src/sentry/workflow_engine/processors/detector.py, line 128:

<comment>Docstring is now stale: it says "returns a list of `DetectorEvaluationResult`" but the return type was changed to `dict[DetectorGroupKey, DetectorEvaluationResult]`. Update the docstring to reflect the new return type.</comment>

<file context>
@@ -136,7 +123,9 @@ def __init__(self, detector: Detector):
-    def evaluate(self, data_packet: DataPacket[T]) -> list[DetectorEvaluationResult]:
+    def evaluate(
+        self, data_packet: DataPacket[T]
+    ) -> dict[DetectorGroupKey, DetectorEvaluationResult]:
         pass
 
</file context>