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/**
* $addFields can be used to add fixed and computed fields to documents while preserving the
* original document. Verify that using $addFields and adding computed fields in a $project yield
* the same result.
*/
(function() {
"use strict";
// For arrayEq.
load("jstests/aggregation/extras/utils.js");
const dbName = "test";
const collName = jsTest.name();
function doExecutionTest(conn) {
const coll = conn.getDB(dbName).getCollection(collName);
coll.drop();
// Insert a bunch of documents of the form above.
const nDocs = 10;
for (let i = 0; i < nDocs; i++) {
assert.writeOK(coll.insert({"_id": i, "2i": i * 2, "3i": i * 3}));
}
// Add the minimum, maximum, and average temperatures, and make sure that doing the same
// with addFields yields the correct answer.
// First compute with $project, since we know all the fields in this document.
let projectPipe = [{
$project: {
"2i": 1,
"3i": 1,
"6i^2": {"$multiply": ["$2i", "$3i"]},
// _id is implicitly included.
}
}];
let correct = coll.aggregate(projectPipe).toArray();
// Then compute the same results using $addFields.
let addFieldsPipe = [{
$addFields: {
"6i^2": {"$multiply": ["$2i", "$3i"]},
// All other fields are implicitly included.
}
}];
let addFieldsResult = coll.aggregate(addFieldsPipe).toArray();
// Then assert they are the same.
assert(arrayEq(addFieldsResult, correct),
"$addFields does not work the same as a $project with computed and included fields");
}
// Test against the standalone started by resmoke.py.
let conn = db.getMongo();
doExecutionTest(conn);
print("Success! Standalone execution use case test for $addFields passed.");
// Test against a sharded cluster.
let st = new ShardingTest({shards: 2});
doExecutionTest(st.s0);
st.stop();
print("Success! Sharding use case test for $addFields passed.");
}());
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