memgraph/tests/unit/query_plan_edge_cases.cpp
florijan 6c22caa80e Query::Plan::Expand with preceeding optional bug fix
Summary:
This diff contains a bug fix for the expansion operators that are currently on dev.
More importantly, it proposes end-to-end testing for edge-cases for which it's a
pain to write single-phase tests. In my opinion this is OK, you're all reviewers so
you can comment.

The test relies on left-to-right query execution. We need this guarantee in tests
like this. I propose renaming "RuleBasedPlanner" to "LeftToRightPlanner" to make
this explicit. As Teon is not here at the moment, will make this a task/discussion.

Reviewers: buda, mislav.bradac, teon.banek, lion

Reviewed By: mislav.bradac

Subscribers: mferencevic, pullbot

Differential Revision: https://phabricator.memgraph.io/D626
2017-08-04 12:16:26 +02:00

62 lines
2.0 KiB
C++

// tests in this suite deal with edge cases in logical operator behavior
// that's not easily testable with single-phase testing. instead, for
// easy testing and latter readability they are tested end-to-end.
#include "gmock/gmock.h"
#include "gtest/gtest.h"
#include "communication/result_stream_faker.hpp"
#include "database/dbms.hpp"
#include "query/interpreter.hpp"
class QueryExecution : public testing::Test {
protected:
Dbms dbms_;
std::unique_ptr<GraphDbAccessor> db_ = dbms_.active();
/** Commits the current transaction and refreshes the db_
* variable to hold a new accessor with a new transaction */
void Commit() {
db_->commit();
auto next_db = dbms_.active();
db_.swap(next_db);
}
/** Executes the query and returns the results.
* Does NOT commit the transaction */
auto Execute(const std::string &query) {
ResultStreamFaker results;
query::Interpreter().Interpret(query, *db_, results, {});
return results.GetResults();
}
};
TEST_F(QueryExecution, MissingOptionalIntoExpand) {
// validating bug where expanding from Null (due to a preceeding optional
// match) exhausts the expansion cursor, even if it's input is still not
// exhausted
Execute(
"CREATE (a:Person {id: 1}), (b:Person "
"{id:2})-[:Has]->(:Dog)-[:Likes]->(:Food )");
Commit();
ASSERT_EQ(Execute("MATCH (n) RETURN n").size(), 4);
auto Exec = [this](bool desc, bool variable) {
// this test depends on left-to-right query planning
FLAGS_query_cost_planner = false;
return Execute(std::string("MATCH (p:Person) WITH p ORDER BY p.id ") +
(desc ? "DESC " : "") +
"OPTIONAL MATCH (p)-->(d:Dog) WITH p, d "
"MATCH (d)-" + (variable ? "[*1]" : "") + "->(f:Food) "
"RETURN p, d, f")
.size();
};
EXPECT_EQ(Exec(false, false), 1);
EXPECT_EQ(Exec(true, false), 1);
EXPECT_EQ(Exec(false, true), 1);
EXPECT_EQ(Exec(true, true), 1);
// TODO test/fix ExpandBreadthFirst once it's operator lands
}