Unittest Antlr Parser for Stdev Agg Expression

test/SparqlAntlrParserTest.cpp

@@ -1855,6 +1855,22 @@ ::testing::Matcher<const SparqlExpression::Ptr&> matchAggregate(
       AD_PROPERTY(Exp, children, ElementsAre(variableExpressionMatcher(child))),
       WhenDynamicCastTo<const AggregateExpr&>(innerMatcher)));
 }
+
+// Return a matcher that checks whether a given `SparqlExpression::Ptr` actually
+// points to an `AggregateExpr` and that the distinctness of the aggregate
+// expression matches. It does not check the child. This is required to test
+// aggregates that implicitly replace their child, like `StdevExpression`.
+template <typename AggregateExpr>
+::testing::Matcher<const SparqlExpression::Ptr&> matchAggregateWithoutChild(
+    bool distinct) {
+  using namespace ::testing;
+  using namespace builtInCallTestHelpers;
+  using Exp = SparqlExpression;
+
+  using enum SparqlExpression::AggregateStatus;
+  auto aggregateStatus = distinct ? DistinctAggregate : NonDistinctAggregate;
+  return Pointee(AD_PROPERTY(Exp, isAggregate, Eq(aggregateStatus)));
+}
 }  // namespace aggregateTestHelpers
 
 // ___________________________________________________________
@@ -1927,14 +1943,15 @@ TEST(SparqlParser, aggregateExpressions) {
       matchAggregate<GroupConcatExpression>(true, V{"?x"}, separator(";")));
 
   // The STDEV expression
-  // TODO<ullingec> Test failing because StdevExpression replaces its child
-
-  // expectAggregate("STDEV(?x)", matchAggregate<StdevExpression>(false,
-  // V{"?x"})); expectAggregate("stdev(?x)",
-  // matchAggregate<StdevExpression>(false, V{"?x"})); A distinct stdev is
-  // probably not very useful, but should be possible anyway
-  // expectAggregate("STDEV(DISTINCT ?x)",
-  //                 matchAggregate<StdevExpression>(true, V{"?x"}));
+  // Here we don't match the child, because StdevExpression replaces it with a
+  // DeviationExpression.
+  expectAggregate("STDEV(?x)",
+                  matchAggregateWithoutChild<StdevExpression>(false));
+  expectAggregate("stdev(?x)",
+                  matchAggregateWithoutChild<StdevExpression>(false));
+  // A distinct stdev is probably not very useful, but should be possible anyway
+  expectAggregate("STDEV(DISTINCT ?x)",
+                  matchAggregateWithoutChild<StdevExpression>(true));
 }
 
 TEST(SparqlParser, Quads) {