Files
mongo/jstests/aggregation/sources/setWindowFields/stddev.js
2021-06-01 14:50:37 +00:00

43 lines
1.3 KiB
JavaScript

/**
* Test that standard deviation works as a window function.
*/
(function() {
"use strict";
load("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 $stdDevPop function.
testAccumAgainstGroup(coll, "$stdDevPop");
// Run the suite of partition and bounds tests against the $stdDevSamp function.
testAccumAgainstGroup(coll, "$stdDevSamp");
// Test that $stdDevPop and $stdDevSamp return null for windows which do not contain numeric values.
let results =
coll.aggregate([
{$addFields: {str: "hiya"}},
{
$setWindowFields: {
sortBy: {ts: 1},
output: {
stdDevPop:
{$stdDevPop: "$str", window: {documents: ["unbounded", "current"]}},
stdDevSamp:
{$stdDevSamp: "$str", window: {documents: ["unbounded", "current"]}},
}
}
}
])
.toArray();
for (let index = 0; index < results.length; index++) {
assert.eq(null, results[index].stdDevPop);
assert.eq(null, results[index].stdDevSamp);
}
})();