Respect explicit selector context in plan synthesiser

flappy/synth.py

@@ -46,29 +46,34 @@ def enumerate(
         max_candidates: int = 3,
         context: Optional[dict] = None,
     ) -> Iterable[CandidatePlan]:
-        selectors = self._extract_selectors(context)
+        selectors, selectors_explicit = self._extract_selectors(context)
         plan_copy = copy.deepcopy(sketch.root)
-        if self._plan_compatible(plan_copy, selectors):
+        if self._plan_compatible(plan_copy, selectors, selectors_explicit):
             yield CandidatePlan(root=plan_copy, score=1.0, rationale="selectors-bound")
-        elif not selectors:
+        elif not selectors_explicit:
             # If no selector information is available, fall back to the raw sketch.
             yield CandidatePlan(root=plan_copy, score=0.0, rationale="identity-no-selectors")
 
-    def _extract_selectors(self, context: Optional[dict]) -> Sequence[str]:
-        if not context:
-            return []
+    def _extract_selectors(self, context: Optional[dict]) -> tuple[List[str], bool]:
+        if not context or "selectors" not in context:
+            return [], False
         selectors = context.get("selectors")
         if isinstance(selectors, (list, tuple)):
-            return selectors
-        return []
+            return list(selectors), True
+        return [], True
 
-    def _plan_compatible(self, node: DSLNode, selectors: Sequence[str]) -> bool:
+    def _plan_compatible(
+        self, node: DSLNode, selectors: Sequence[str], selectors_explicit: bool
+    ) -> bool:
         if node.verb in {DSLVerb.CLICK, DSLVerb.TYPE} and node.args:
             selector = node.args[0]
-            if selector and selectors and selector not in selectors:
-                return False
+            if selector:
+                if selectors and selector not in selectors:
+                    return False
+                if selectors_explicit and not selectors:
+                    return False
         for child in node.children:
-            if not self._plan_compatible(child, selectors):
+            if not self._plan_compatible(child, selectors, selectors_explicit):
                 return False
         return True
 

tests/test_flappy_stubs.py

@@ -45,6 +45,15 @@ def test_plan_synthesiser_identity():
     assert proposals[0].root.to_dict() == leaf.to_dict()
 
 
+def test_plan_synthesiser_empty_selectors_rejects_missing():
+    leaf = dsl.make_leaf(dsl.DSLVerb.CLICK, "#missing")
+    sketch = synth.Sketch(root=leaf, holes=[])
+    proposals = list(
+        synth.PlanSynthesiser().enumerate(sketch, context={"selectors": []})
+    )
+    assert not proposals
+
+
 def test_verifier_stub():
     verifier = verify.PlanVerifier()
     result = verifier.verify(