message: Add testcase for interleaved usage of appender and connection
diff: @@ -204,3 +204,24 @@ TEST_CASE("Test using multiple appenders", "[api]") {
  result = con.Query("SELECT * FROM t1");
  REQUIRE(CHECK_COLUMN(result, 0, {}));
  }
  +
  +TEST_CASE("Test usage of appender interleaved with connection usage", "[api]") {
  + DuckDB db(nullptr);
  + Connection con(db);
  + unique_ptr<QueryResult> result;
  + // create the table
  + REQUIRE_NO_FAIL(con.Query("CREATE TABLE t1(i INTEGER)"));
  + Appender appender(con, "t1");
  +
  + appender.AppendRow(1);
  + appender.Flush();
  +
  + result = con.Query("SELECT * FROM t1");
  + REQUIRE(CHECK_COLUMN(result, 0, {1}));
  +
  + appender.AppendRow(2);
  + appender.Flush();
  +
  + result = con.Query("SELECT * FROM t1");
  + REQUIRE(CHECK_COLUMN(result, 0, {1, 2}));
  +}
  