fix(jexl): properly cache is_hidden/is_required

To speed up is_hidden/is_required evaluations, we cache the
result. However, the cache key used must be local to the document of
the answer, as otherwise the value might be wrong for table answers
(assume row 1 evaluated to another result than row 2 would, then we
wouldn't notice)

caluma/caluma_form/jexl.py

@@ -114,15 +114,20 @@ def _all_containers_hidden(self, question):
 
         return res
 
+    def _cache_key(self, question_slug):
+        field = self._structure.get_field(question_slug)
+        return (field.document.pk, question_slug)
+
     def is_hidden(self, question):
         """Return True if the given question is hidden.
 
         This checks whether the dependency questions are hidden, then
         evaluates the question's is_hidden expression itself.
         """
+        cache_key = self._cache_key(question.pk)
 
-        if question.pk in self._cache["hidden"]:
-            return self._cache["hidden"][question.pk]
+        if cache_key in self._cache["hidden"]:
+            return self._cache["hidden"][cache_key]
         # Check visibility of dependencies before actually evaluating the `is_hidden`
         # expression. If all dependencies are hidden,
         # there is no way to evaluate our own visibility, so we default to
@@ -136,23 +141,25 @@ def is_hidden(self, question):
             self.is_hidden(self._question(dep)) for dep in deps
         )
         if all_deps_hidden:
-            self._cache["hidden"][question.pk] = True
+            self._cache["hidden"][cache_key] = True
             return True
 
         # Also check if the question is hidden indirectly,
         # for example via parent formquestion.
         if self._all_containers_hidden(question):
             # no way this is shown somewhere
-            self._cache["hidden"][question.pk] = True
+            self._cache["hidden"][cache_key] = True
             return True
         # if the question is visible-in-context and not hidden by invisible dependencies,
         # we can evaluate it's own is_hidden expression
-        self._cache["hidden"][question.pk] = self.evaluate(question.is_hidden)
-        return self._cache["hidden"][question.pk]
+        self._cache["hidden"][cache_key] = self.evaluate(question.is_hidden)
+        return self._cache["hidden"][cache_key]
 
     def is_required(self, question):
-        if question.pk in self._cache["required"]:
-            return self._cache["required"][question.pk]
+        cache_key = self._cache_key(question.pk)
+
+        if cache_key in self._cache["required"]:
+            return self._cache["required"][cache_key]
 
         deps = list(self.extract_referenced_questions(question.is_required))
 
@@ -162,5 +169,5 @@ def is_required(self, question):
             ret = False
         else:
             ret = self.evaluate(question.is_required)
-        self._cache["required"][question.pk] = ret
+        self._cache["required"][cache_key] = ret
         return ret

caluma/caluma_form/tests/test_jexl.py

@@ -347,3 +347,37 @@ def test_answer_transform_on_hidden_question_types(
     )
 
     assert qj.is_hidden(questions["form_question"])
+
+
+def test_answer_transform_in_tables(info, form_and_document, form_question_factory):
+    # Bug test: When a JEXL expression references two answers, and one of them
+    # is hidden, the `answer` transform must return None for the hidden question
+    # to ensure correct evaluation.
+
+    form, document, questions, answers = form_and_document(
+        use_table=True, use_subform=False
+    )
+
+    table_question = questions["table_question"]
+
+    question_col1 = questions["column"]
+    question_col2 = form_question_factory(
+        form=table_question.row_form,
+        question__slug="column2",
+        question__is_required="'column'|answer == 5",
+    ).question
+
+    table_answer = answers["table_question"]
+
+    ans_doc_1 = table_answer.documents.first()
+    ans_doc_2 = table_answer.documents.create(form=table_question.row_form)
+
+    ans_row1_col1 = ans_doc_1.answers.get(question_id="column")
+    ans_row2_col1 = ans_doc_2.answers.create(question_id="column", value=5)
+
+    validator = validators.DocumentValidator()
+
+    # we expect this to fail, as in the second row, the 'column' answer is 5,
+    # so 'column2' should be required
+    with pytest.raises(validators.CustomValidationError):
+        validator.validate(document, info)