mongodb/jstests/noPassthroughWithMongod/default_read_pref.js

// Tests that the default read preference is 'unset', and that the slaveOk bit is not set
// on read commands run with an 'unset' read preference.
(function() {

"use strict";

var mongo = db.getMongo();
try {
    var commandsRan = [];
    db._mongo = {
        getSlaveOk: function() {
            return false;
        },
        getReadPrefMode: function() {
            return mongo.getReadPrefMode();
        },
        getReadPref: function() {
            return mongo.getReadPref();
        },
        runCommand: function(db, cmd, opts) {
            commandsRan.push({db: db, cmd: cmd, opts: opts});
            return {ok: 1};
        },
        getMinWireVersion: function() {
            return mongo.getMinWireVersion();
        },
        getMaxWireVersion: function() {
            return mongo.getMaxWireVersion();
        },
        isReplicaSetMember: function() {
            return mongo.isReplicaSetMember();
        },
        isMongos: function() {
            return mongo.isMongos();
        },
        isCausalConsistency: function() {
            return false;
        },
        getClusterTime: function() {
            return null;
        },
    };
    db._session = new _DummyDriverSession(db._mongo);

    db.runReadCommand({ping: 1});
    assert.eq(commandsRan.length, 1);
    assert.docEq(commandsRan[0].cmd, {ping: 1}, "The command should not have been wrapped.");
    assert.eq(
        commandsRan[0].opts & DBQuery.Option.slaveOk, 0, "The slaveOk bit should not be set.");

} finally {
    db._mongo = mongo;
    db._session = new _DummyDriverSession(mongo);
}
})();