/*
 * Tests that upgrade/downgrade works correctly even while creating a new collection.
 */
(function() {
"use strict";
load("jstests/libs/feature_compatibility_version.js");
load("jstests/libs/parallel_shell_helpers.js");

const rst = new ReplSetTest({nodes: 2});
rst.startSet();

// Rig the election so that the first node is always primary and that modifying the
// featureCompatibilityVersion document doesn't need to wait for data to replicate.
var replSetConfig = rst.getReplSetConfig();
replSetConfig.members[1].priority = 0;
replSetConfig.members[1].votes = 0;

rst.initiate(replSetConfig);

const primary = rst.getPrimary();
const primaryDB = primary.getDB("test");

for (let versions of [{from: lastStableFCV, to: latestFCV}, {from: latestFCV, to: lastStableFCV}]) {
    jsTestLog("Changing FeatureCompatibilityVersion from " + versions.from + " to " + versions.to +
              " while creating a collection");
    assert.commandWorked(primaryDB.adminCommand({setFeatureCompatibilityVersion: versions.from}));

    assert.commandWorked(primaryDB.adminCommand(
        {configureFailPoint: "hangBeforeLoggingCreateCollection", mode: "alwaysOn"}));
    primaryDB.mycoll.drop();

    let awaitCreateCollection;
    let awaitUpgradeFCV;

    try {
        awaitCreateCollection = startParallelShell(function() {
            assert.commandWorked(db.runCommand({create: "mycoll"}));
        }, primary.port);

        assert.soon(function() {
            return rawMongoProgramOutput().match("createCollection: test.mycoll");
        });

        awaitUpgradeFCV = startParallelShell(
            funWithArgs(function(version) {
                assert.commandWorked(db.adminCommand({setFeatureCompatibilityVersion: version}));
            }, versions.to), primary.port);

        {
            let res;
            assert.soon(
                function() {
                    res = assert.commandWorked(
                        primaryDB.adminCommand({getParameter: 1, featureCompatibilityVersion: 1}));
                    return res.featureCompatibilityVersion.version === versions.from &&
                        res.featureCompatibilityVersion.targetVersion === versions.new;
                },
                function() {
                    return "targetVersion of featureCompatibilityVersion document wasn't " +
                        "updated on primary: " + tojson(res);
                });
        }
    } finally {
        assert.commandWorked(primaryDB.adminCommand(
            {configureFailPoint: "hangBeforeLoggingCreateCollection", mode: "off"}));
    }

    awaitCreateCollection();
    awaitUpgradeFCV();
    rst.checkReplicatedDataHashes();
}
rst.stopSet();
})();