Fix bug in parenthesized expression

Reviewers: buda

Reviewed By: buda

Subscribers: pullbot

Differential Revision: https://phabricator.memgraph.io/D249

src/query/frontend/ast/cypher_main_visitor.cpp

@@ -360,7 +360,7 @@ antlrcpp::Any CypherMainVisitor::visitRangeLiteral(
 
 antlrcpp::Any CypherMainVisitor::visitExpression(
     CypherParser::ExpressionContext *ctx) {
-  return visitChildren(ctx);
+  return static_cast<Expression *>(ctx->expression12()->accept(this));
 }
 
 // OR.
@@ -499,7 +499,7 @@ antlrcpp::Any CypherMainVisitor::visitExpression3(
   if (ctx->children.size() > 1u) {
     throw NotYetImplemented();
   }
-  return visitChildren(ctx);
+  return static_cast<Expression *>(visitChildren(ctx));
 }
 
 antlrcpp::Any CypherMainVisitor::visitExpression2(
@@ -525,11 +525,12 @@ antlrcpp::Any CypherMainVisitor::visitAtom(CypherParser::AtomContext *ctx) {
     // TODO: implement other clauses.
     throw NotYetImplemented();
   } else if (ctx->parenthesizedExpression()) {
-    return ctx->parenthesizedExpression()->accept(this);
+    return static_cast<Expression *>(
+        ctx->parenthesizedExpression()->accept(this));
   } else if (ctx->variable()) {
     std::string variable = ctx->variable()->accept(this);
     users_identifiers.insert(variable);
-    return (Expression *)storage_.Create<Identifier>(variable);
+    return static_cast<Expression *>(storage_.Create<Identifier>(variable));
   }
   // TODO: Implement this. We don't support comprehensions, functions,
   // filtering... at the moment.
@@ -556,6 +557,11 @@ antlrcpp::Any CypherMainVisitor::visitLiteral(
   return visitChildren(ctx);
 }
 
+antlrcpp::Any CypherMainVisitor::visitParenthesizedExpression(
+    CypherParser::ParenthesizedExpressionContext *ctx) {
+  return static_cast<Expression *>(ctx->expression()->accept(this));
+}
+
 antlrcpp::Any CypherMainVisitor::visitNumberLiteral(
     CypherParser::NumberLiteralContext *ctx) {
   if (ctx->integerLiteral()) {

src/query/frontend/ast/cypher_main_visitor.hpp

@@ -350,20 +350,26 @@ class CypherMainVisitor : public antlropencypher::CypherBaseVisitor {
       CypherParser::Expression3Context *ctx) override;
 
   /**
-  * Property lookup, test for node labels existence...
-  *
-  * @return Expression*
-  */
+   * Property lookup, test for node labels existence...
+   *
+   * @return Expression*
+   */
   antlrcpp::Any visitExpression2(
       CypherParser::Expression2Context *ctx) override;
 
   /**
-  * Literals, params, list comprehension...
-  *
-  * @return Expression*
-  */
+   * Literals, params, list comprehension...
+   *
+   * @return Expression*
+   */
   antlrcpp::Any visitAtom(CypherParser::AtomContext *ctx) override;
 
+  /**
+   * @return Expression*
+   */
+  antlrcpp::Any visitParenthesizedExpression(
+      CypherParser::ParenthesizedExpressionContext *ctx) override;
+
   /**
    * @return Literal*
    */

tests/unit/cypher_main_visitor.cpp

@@ -121,6 +121,16 @@ TEST(CypherMainVisitorTest, NullLiteral) {
   ASSERT_EQ(literal->value_.type(), TypedValue::Type::Null);
 }
 
+TEST(CypherMainVisitorTest, ParenthesizedExpression) {
+  AstGenerator ast_generator("RETURN (2)");
+  auto *query = ast_generator.query_;
+  auto *return_clause = dynamic_cast<Return *>(query->clauses_[0]);
+  auto *literal = dynamic_cast<Literal *>(
+      return_clause->named_expressions_[0]->expression_);
+  ASSERT_TRUE(literal);
+  ASSERT_EQ(literal->value_.Value<int64_t>(), 2);
+}
+
 TEST(CypherMainVisitorTest, OrOperator) {
   AstGenerator ast_generator("RETURN true Or false oR n");
   auto *query = ast_generator.query_;