dbjs-persistence/lib/receiver.js

Persistence for dbjs

'use strict';

var forEach        = require('es5-ext/object/for-each')
  , isObject       = require('es5-ext/object/is-object')
  , ensureCallable = require('es5-ext/object/valid-callable')
  , ensureObject   = require('es5-ext/object/valid-object')
  , ensureString   = require('es5-ext/object/validate-stringifiable-value')
  , deferred       = require('deferred');

var getSafeErrorObject = function (error) {
	var safeError = { message: error.message, stack: error.stack };
	if (error.code) safeError.code = error.code;
	forEach(error, function (value, name) {
		if (isObject(value)) return;
		safeError[name] = value;
	});
	return safeError;
};

module.exports = function (type, callback/*, emitterProcess*/) {
	var emitterProcess = arguments[2], listener;
	ensureString(type);
	ensureCallable(callback);
	if (emitterProcess != null) ensureObject(emitterProcess);
	else emitterProcess = process;
	emitterProcess.on('message', listener = function (req) {
		var promise;
		if (req.type !== type) return;
		ensureString(req.id);
		try {
			promise = callback(req.req);
		} catch (e) {
			promise = deferred.reject(e);
		}
		deferred(promise).done(function (res) {
			emitterProcess.send({
				id: req.id,
				confirmed: true,
				res: res
			});
		}, function (error) {
			emitterProcess.send({
				id: req.id,
				error: getSafeErrorObject(error),
				res: error
			});
		});
	});
	return {
		destroy: function () { emitterProcess.removeListener('message', listener); }
	};
};