// Cannot implicitly shard accessed collections because of extra shard key index in sharded
// collection.
// @tags: [assumes_no_implicit_index_creation]
(function() {
'use strict';

const t = db.drop_index;
t.drop();

/**
 * Extracts index names from listIndexes result.
 */
function getIndexNames(cmdRes) {
    return t.getIndexes().map(spec => spec.name);
}

/**
 * Checks that collection contains the given list of non-id indexes and nothing else.
 */
function assertIndexes(expectedIndexNames, msg) {
    const actualIndexNames = getIndexNames();
    const testMsgSuffix = () => msg + ': expected ' + tojson(expectedIndexNames) + ' but got ' +
        tojson(actualIndexNames) + ' instead.';
    assert.eq(expectedIndexNames.length + 1,
              actualIndexNames.length,
              'unexpected number of indexes after ' + testMsgSuffix());
    assert(actualIndexNames.includes('_id_'),
           '_id index missing after ' + msg + ': ' + tojson(actualIndexNames));
    for (let expectedIndexName of expectedIndexNames) {
        assert(actualIndexNames.includes(expectedIndexName),
               expectedIndexName + ' index missing after ' + testMsgSuffix());
    }
}

assert.commandWorked(t.insert({_id: 1, a: 2, b: 3, c: 1, d: 1, e: 1}));
assertIndexes([], 'inserting test document');

assert.commandWorked(t.createIndex({a: 1}));
assert.commandWorked(t.createIndex({b: 1}));
assert.commandWorked(t.createIndex({c: 1}));
assert.commandWorked(t.createIndex({d: 1}));
assert.commandWorked(t.createIndex({e: 1}));
assertIndexes(['a_1', 'b_1', 'c_1', 'd_1', 'e_1'], 'creating indexes');

// Drop single index by name.
// Collection.dropIndex() throws if the dropIndexes command fails.
t.dropIndex(t._genIndexName({a: 1}));
assertIndexes(['b_1', 'c_1', 'd_1', 'e_1'], 'dropping {a: 1} by name');

// Drop single index by key pattern.
t.dropIndex({b: 1});
assertIndexes(['c_1', 'd_1', 'e_1'], 'dropping {b: 1} by key pattern');

// Not allowed to drop _id index.
assert.commandFailedWithCode(t.dropIndex('_id_'), ErrorCodes.InvalidOptions);
assert.commandFailedWithCode(t.dropIndex({_id: 1}), ErrorCodes.InvalidOptions);

// Ensure you can recreate indexes, even if you don't use dropIndex method.
// Prior to SERVER-7168, the shell used to cache names of indexes created using
// Collection.ensureIndex().
assert.commandWorked(t.createIndex({a: 1}));
assertIndexes(['a_1', 'c_1', 'd_1', 'e_1'], 'recreating {a: 1}');

// Drop single index with dropIndexes().
assert.commandWorked(t.dropIndexes(['c_1']));
assertIndexes(['a_1', 'd_1', 'e_1'], 'dropping {c: 1}');
}());