Allow ; after update request with a single operation (#1750)

QLever does not yet support update requests with more than one operation, e.g., `DELETE DATA { <pi> <value> 3.14 }; INSERT DATA { <pi> <value> 3.1459 }`. Due to an oversight, the current implementation also did not support single operations followed by a semicolon, e.g., `DELETE DATA { <pi> <value> 3.14 };`. These are now supported. Fixes #1747

NOTE: Support for multiple operations in a single update request will be added soon.

src/parser/sparqlParser/SparqlQleverVisitor.cpp

@@ -438,15 +438,17 @@ std::optional<Values> Visitor::visit(Parser::ValuesClauseContext* ctx) {
   return visitOptional(ctx->dataBlock());
 }
 
-// ____________________________________________________________________________________
+// ____________________________________________________________________________
 ParsedQuery Visitor::visit(Parser::UpdateContext* ctx) {
   // The prologue (BASE and PREFIX declarations)  only affects the internal
   // state of the visitor.
   visit(ctx->prologue());
 
   auto update = visit(ctx->update1());
 
-  if (ctx->update()) {
+  // More than one operation in a single update request is not yet supported,
+  // but a semicolon after a single update is allowed.
+  if (ctx->update() && !ctx->update()->getText().empty()) {
     parsedQuery_ = ParsedQuery{};
     reportNotSupported(ctx->update(), "Multiple updates in one query are");
   }

test/SparqlAntlrParserTest.cpp

@@ -2050,10 +2050,12 @@ TEST(SparqlParser, QuadData) {
 TEST(SparqlParser, Update) {
   auto expectUpdate_ = ExpectCompleteParse<&Parser::update>{defaultPrefixMap};
   // Automatically test all updates for their `_originalString`.
-  auto expectUpdate = [&expectUpdate_](const std::string& query,
-                                       auto&& expected) {
-    expectUpdate_(query,
-                  testing::AllOf(expected, m::pq::OriginalString(query)));
+  auto expectUpdate = [&expectUpdate_](
+                          const std::string& query, auto&& expected,
+                          ad_utility::source_location l =
+                              ad_utility::source_location::current()) {
+    expectUpdate_(query, testing::AllOf(expected, m::pq::OriginalString(query)),
+                  l);
   };
   auto expectUpdateFails = ExpectParseFails<&Parser::update>{};
   auto Iri = [](std::string_view stringWithBrackets) {
@@ -2185,6 +2187,21 @@ TEST(SparqlParser, Update) {
   expectUpdate("COPY DEFAULT TO GRAPH <foo>",
                m::UpdateClause(m::Copy(false, DEFAULT{}, Iri("<foo>")),
                                m::GraphPattern()));
+  const auto simpleInsertMatcher = m::UpdateClause(
+      m::GraphUpdate({}, {{Iri("<a>"), Iri("<b>"), Iri("<c>"), noGraph}},
+                     std::nullopt),
+      m::GraphPattern());
+  expectUpdate("INSERT DATA { <a> <b> <c> }", simpleInsertMatcher);
+  expectUpdate("INSERT DATA { <a> <b> <c> };", simpleInsertMatcher);
+  const auto multipleUpdatesError = testing::HasSubstr(
+      "Not supported: Multiple updates in one query are "
+      "currently not supported by QLever");
+  expectUpdateFails("INSERT DATA { <a> <b> <c> }; PREFIX foo: <foo>",
+                    multipleUpdatesError);
+  expectUpdateFails("INSERT DATA { <a> <b> <c> }; BASE <bar>",
+                    multipleUpdatesError);
+  expectUpdateFails("INSERT DATA { <a> <b> <c> }; INSERT DATA { <d> <e> <f> }",
+                    multipleUpdatesError);
 }
 
 TEST(SparqlParser, QueryOrUpdate) {