Delete all documents from a Cloudant view

deleteDocsFromCloudantView.js

var async = require("async");
var _ = require("lodash");

function deleteDocsFromView( db, designName, viewName, callback){
	async.waterfall([
    function( callback ){
    	db.view(designName, viewName, function(err, data) {
			  if ( err ){
					return callback( err );
				}
				var docs = _.map( data.rows, function( row ){
					return {id: row.id || row.value._id, rev: row.value.rev||row.value._rev};
				});					
				return callback( null, docs );
      });
    },
    function( docs, callback ){
    	if ( docs.length == 0 || docs[0].rev ){
    		//We either have no docs to delete, or rev is already retrieved
    		return callback( null, docs );
    	}
      //Call bulk api to fetch revs
      db.fetchRevs( { keys: _.map( docs, function(doc){
      	return doc.id;
      })}, function( err, body ){
  			if ( err ){
        	return callback( err );
        }
        return callback( null, _.map(body.rows, function( row ){
        	return {id:row.id, rev: row.value.rev};
        }));
      });
    },
    function( docs, callback ){
    	//Delete all docs one by one
    	async.each( docs, function( doc, callback ){
    		db.destroy( doc.id, doc.rev, callback );
    	}, function( err ){
    		return callback( err );
    	});
    }],
    function( err, results ){
			return callback( err, results );
		}
	);
});