Clean-up non-design-docs from a CouchDb at the beginning of each test

cleanDb.js

var db = require('nano');
var debug = require('debug')('cleanDb');
var async = require('async');

function cleanDb(callback) {

    debug('Cleaning up db from all non-design documents');

    db.list(function(err, body) {
        if(err) {
            return callback(err);
        }

        debug('Marking all non-design documents out of', body.rows.length, 'as deleted');

        var docs = [];
        return async.each(
            body.rows,
            function(doc, next) {
                if(!doc) {
                    return next('doc undefined');
                }

                //  Don't destroy the design docs.
                if(doc.id.indexOf('_design/') === 0) {
                    return next();
                }

                docs.push({
                    _id:        doc.id,
                    _rev:       doc.value.rev,
                    _deleted:   true
                });
                return next();
            },
            function(err) {
                if(err) {
                    return callback(err);
                }

                debug('Bulk uploading changes to', docs.length, 'deleted docs.');

                return db.bulk({ docs: docs }, function(err) {
                    debug('Done deleting non-design docs.');

                    callback(err);
                });
            }
        );
    });

}