What is Changing?

The major difference in the Profound.js 6 framework is the change from Fibers to Promises. Starting in Profound.js 6, all framework APIs return Promises and applications run in a top-down manner using the async/await keywords. Profound.js 6 is largely, but not entirely, backwards compatible with Profound.js 5.

Profound.js 5 Fix Pack 8 (5.8.0), released on 3/4/2022, is the last feature update for the Fibers-based Profound.js 5 framework. Profound Logic will continue to support this release with fix updates for 1 year following the release of Profound.js 6. Profound.js 5 runs on Node.js 14, which is scheduled for end of life on 4/30/2023. New features will only be available in Profound.js 6, which runs on Node 14, Node 16, and future versions of Profound.js. These dates are coming up quickly, so you are strongly encouraged to migrate to Profound.js 6 as soon as possible.

Why This Change? Why Promises?

Development on Profound.js started in late 2015, using Node.js 4. A key goal of the framework from the beginning was to simplify Node.js programming and eliminate the notorious Callback Hell. But at that time, there was not a built-in way of coding asynchronous I/O in Node.js in a top-down manner.

The ECMAScript 6 standard that introduced Promises and async/await was just finalized around this time, and these features were not included in a Long-Term Support (LTS) version of Node.js until Node.js 8 in late 2017. On the other hand, the Fibers addon provided the needed capability and was used by other popular frameworks at the time, such as Meteor, so it was a logical choice.

Since then, Promises and async/await have become the standard for top-down asynchronous coding in Node.js. In April 2021 Node.js 16 was released which includes changes that break compatibility with the Fibers addon. The Fibers author announced that the project has run its course and decided to stop making updates.

So, this change is necessary to move Profound.js forward, support current/future Node.js versions, and keep in tune with the Node.js ecosystem.

What Does This Mean for My Existing Applications?

For the most part, existing applications written for Profound.js 5 will continue to work with Profound.js 6. However, top-down programming with Promises is very different than with Fibers and it’s not guaranteed that all existing applications will run as-is on Profound.js 6. Some applications may require minor modifications.

Existing applications may need slight adjustments to add async and await keywords for Promises where Profound.js module transformation is not able to do so automatically. For details, see Coding With Promises in Profound.js and the section Limitations of Module Transformation.

Conversion of Start.js Files

When upgrading an existing Profound.js installation to version 6, the start.js file will be automatically adjusted to work with Promises. For example, a file like this:

#!/usr/bin/env node
var profoundjs = require("profoundjs");
var config = require("./config.js");
profoundjs.applyConfig(config);
var isWorker = profoundjs.server.listen();
if (isWorker) {
  var express = profoundjs.server.express;
  var app = profoundjs.server.app;
  app.use(express.json());
}

Will be converted to this:

#!/usr/bin/env node
async function startPJS() {
  var profoundjs = require("profoundjs");
  var config = require("./config.js");
  profoundjs.applyConfig(config);
  var isWorker = await profoundjs.server.listen();
  if (isWorker) {
    var express = profoundjs.server.express;
    var app = profoundjs.server.app;
    app.use(express.json());
  }
}
startPJS();

The conversion process retains a copy of the original file as start.js.orig.TIME_STAMP