// @tags: [
//   does_not_support_stepdowns,
//   uses_testing_only_commands,
// ]

// Test basic query stage collection scan functionality.
t = db.stages_collection_scan;
t.drop();
var collname = "stages_collection_scan";

var N = 50;
for (var i = 0; i < N; ++i) {
    t.insert({foo: i});
}

forward = {
    cscan: {args: {direction: 1}}
};
res = db.runCommand({stageDebug: {collection: collname, plan: forward}});
assert.eq(res.ok, 1);
assert.eq(res.results.length, N);
assert.eq(res.results[0].foo, 0);
assert.eq(res.results[49].foo, 49);

// And, backwards.
backward = {
    cscan: {args: {direction: -1}}
};
res = db.runCommand({stageDebug: {collection: collname, plan: backward}});
assert.eq(res.ok, 1);
assert.eq(res.results.length, N);
assert.eq(res.results[0].foo, 49);
assert.eq(res.results[49].foo, 0);

forwardFiltered = {
    cscan: {args: {direction: 1}, filter: {foo: {$lt: 25}}}
};
res = db.runCommand({stageDebug: {collection: collname, plan: forwardFiltered}});
assert.eq(res.ok, 1);
assert.eq(res.results.length, 25);
assert.eq(res.results[0].foo, 0);
assert.eq(res.results[24].foo, 24);

backwardFiltered = {
    cscan: {args: {direction: -1}, filter: {foo: {$lt: 25}}}
};
res = db.runCommand({stageDebug: {collection: collname, plan: backwardFiltered}});
assert.eq(res.ok, 1);
assert.eq(res.results.length, 25);
assert.eq(res.results[0].foo, 24);
assert.eq(res.results[24].foo, 0);