/**
 * Test that $push works as a window function.
 */
import {seedWithTickerData, testAccumAgainstGroup} from "jstests/aggregation/extras/window_function_helpers.js";

const coll = db[jsTestName()];
coll.drop();

// Create a collection of tickers and prices.
const nDocsPerTicker = 10;
seedWithTickerData(coll, nDocsPerTicker);

// Run the suite of partition and bounds tests against the $push function.
testAccumAgainstGroup(coll, "$push", []);

// Test $push with empty fields.
coll.drop();
assert.commandWorked(coll.insert([{_id: 0}, {_id: 1, a: "a"}, {_id: 2}]));
const result = coll
    .aggregate([
        {
            $setWindowFields: {sortBy: {_id: 1}, output: {b: {$push: "$a", window: {documents: [-1, 0]}}}},
        },
    ])
    .toArray();
assert.eq(3, result.length, result);
assert.docEq({_id: 0, b: []}, result[0], result);
assert.docEq({_id: 1, a: "a", b: ["a"]}, result[1], result);
assert.docEq({_id: 2, b: ["a"]}, result[2], result);