/**
 * Confirms that the aggregate command accepts writeConcern regardless of whether the pipeline
 * writes or is read-only.
 * @tags: [assumes_write_concern_unchanged, does_not_support_stepdowns]
 */
(function() {
    "use strict";

    const testDB = db.getSiblingDB("aggregation_accepts_write_concern");
    assert.commandWorked(testDB.dropDatabase());
    const collName = "test";

    assert.commandWorked(testDB.runCommand(
        {insert: collName, documents: [{_id: 1}], writeConcern: {w: "majority"}}));

    // A read-only aggregation accepts writeConcern.
    assert.commandWorked(testDB.runCommand({
        aggregate: collName,
        pipeline: [{$match: {_id: 1}}],
        cursor: {},
        writeConcern: {w: "majority"}
    }));

    // An aggregation pipeline that writes accepts writeConcern.
    assert.commandWorked(testDB.runCommand({
        aggregate: collName,
        pipeline: [{$match: {_id: 1}}, {$out: collName + "_out"}],
        cursor: {},
        writeConcern: {w: "majority"}
    }));
})();