proposals VS Capybara

target - Specifies the ECMAScript target version for the emitted JavaScript. Defaults to ES3. To ensure maximum compatibility, set this to the lowest version that your code requires to run. ESNext setting allows you to target the latest supported proposed features.

TC39

Current Status: You'd have to check the TC39 proposals repository or the official proposal text for the most recent status. As of my last update, it had not yet reached Stage 4 (final stage) of the TC39 process, which means it wasn't part of the ECMAScript specification yet.

More proposals can be found on the official GitHub page.

There were a couple of other proposals that made stage 1 too, can see here.

The working group most in charge of JS is ECMA's TC-39 (TC => Technical Committee) [0]. They've been taking a very deliberate, slow path to expanding the "standard" library because they take a very serious view of backwards compatibility on the web. Some proposals were shifted because of conflicts with ancient versions of things like MooTools still out in the wild, for instance. (This was the so-called "Smooshgate" incident [1].)

This may speed up a bit if the Built-In Modules proposal [2] passes, which would add a deliberate `import` URL for standard modules which would give a cleaner expansion point for new standard libraries over adding more global variables or further expanding the base prototypes (Object.prototype, Array.prototype, etc) in ways that increasingly likely have backwards compatibility issues.

TC-39 works all of their proposals in the open on Github [3] and it can be a fascinating process to watch if you are interested in the language's future direction.

[0] https://tc39.es/

[1] https://developers.google.com/web/updates/2018/03/smooshgate

[2] https://github.com/tc39/proposal-built-in-modules

[3] https://github.com/tc39/proposals

My biggest pointer would be to remember that Java & JavaScript aren't named that way by coincidence. They're two different approaches to a similar problem. Java suffers from Enterprise Development (eg: Enterprise FizzBuzz[0]), JavaScript suffers from Ultimate Accessibility (eg: how many questions on Stack Overflow conflated jQuery and JS?).

> How should exceptions be managed? [...] Has there been a debate about best practice? Where can I find it?

I suggest you handle the errors you can and otherwise let it crash.[1][2] Debates in NodeJS-land have steered towards more monadic/Result-like structures and working synchronous-looking try/catch onto async/await. NodeJS and its various components are open source, you'll have a lot of luck looking around on GH for issues & PRs related to a feature -- same for the language, ECMAScript[3] officially.[4]

Since you mentioned Clojure, have you looked at ClojureScript?[5] That may be a good entry to JS authors & articles you'd enjoy.

> I have the impression that NodeJS is a bit more magical than the JVM [...] Is that correct? Where are good resources on this subject?

As other replies have mentioned, you're really talking about V8[6] for the "JSVM" executing that code. A thing I've seen throw some people for a loop is how minimalist the specification actually is.[7] The magic in NodeJS is certainly from V8 and the rate of optimizations there but also libuv,[8] what actually powers the infamous event loop.

Hope that helps!

[0]: https://github.com/EnterpriseQualityCoding/FizzBuzzEnterpris...

[1]: Borrowing from Erlang, see Making reliable distributed systems in the presence of software errors, Joe Armstrong, page 104 "Error Handling Philosophy" https://erlang.org/download/armstrong_thesis_2003.pdf

[2]: _Most_ kinds of errors will cause the process to crash if you don't handle them, https://nodejs.org/dist/latest-v16.x/docs/api/errors.html . Promise rejections don't (yet) though it emits an error, and callback-based APIs will always consist of an [error, data] tuple for the arguments

[3]: https://github.com/tc39/proposals

[4]: Because Oracle owns the trademark, of course: http://tarr.uspto.gov/servlet/tarr?regser=serial&entry=

[5]: https://clojurescript.org/

[6]: https://v8.dev/docs

[7]: "ECMAScript as defined here is not intended to be computationally self-sufficient; indeed, there are no provisions in this specification for input of external data or output of computed results. Instead, it is expected that the computational environment of an ECMAScript program will provide not only the objects and other facilities described in this specification but also certain environment-specific objects, whose description and behaviour are beyond the scope of this specification except to indicate that they may provide certain properties that can be accessed and certain functions that can be called from an ECMAScript program." https://tc39.es/ecma262/#sec-overview

[8]: https://github.com/libuv/libuv

Cuba takes help from a lot of other technologies to bring the best of everything. For example, the responses in Cuba are the optimized version of the Rack responses. The templates are integrated via Tilt and testing via Cutest and Capybara.

I am going to use a browser based testing tool called Playwright (But you could use Capybara, or Selenium WebDriver etc.).

Even as a much smaller team, building Heii On-Call [0] as a lightweight alerting/monitoring/on-call rotations SaaS based on Ruby on Rails has basically been a pleasure!

And as the article highlights, perhaps the key reason for smooth deployments and upgrades is that the CI testing story is so, so good: RSpec [1] plus Capybara [2] for us. That means we have decently extensive tests of just about all behavior. The few small Rails and Ruby upgrades we've done have gone quite smoothly and confidently, with usually just a few non-Rails gem dependencies needing to be manually updated as well.

The "microservices" story is where we've pulled in the Crystal programming language [3] to great effect. After dabbling with Go and Rust, we've found that Crystal is truly a breath of fresh air. Crystal powers the parts of Heii On-Call that need to be fast and low-RAM, specifically the inbound API https://api.heiioncall.com/ and the outbound HTTP(S) prober background processes. I've ported some shared utility classes from Ruby to Crystal almost completely by just copy-and-pasting ___.rb to ___.cr; porting the tests for those classes was far more onerous than porting the class code itself. (Perhaps another point of evidence toward the superiority of RoR's testing story...)

The front-end story is nice but just a bit weaker. Using Hotwire / Turbo successfully, but I have an open PR to fix a fairly obvious stale cache bug in Turbo [4] that has been sitting unloved for nearly a month, despite other users reporting the same issue. I'm hopeful that it will get merged in the next release, but definitely less active than the backend side.

For me, the key conclusion is that the excellent Ruby on Rails testing story is what enables everything to go a lot more smoothly and have such a strong foundation. I'd be curious if any GitHubbers can talk more about whether they too are using Rspec+Capybara or something else? Are there internal guidelines for test coverage?

[0] https://heiioncall.com/

[1] https://rspec.info/

[2] https://github.com/teamcapybara/capybara

[3] https://crystal-lang.org/

[4] https://github.com/hotwired/turbo/pull/895

Engineering at Aha! focuses on using and improving the Capybara test framework. We have added many helpers and additional functionality to make working with Capybara easy. Testing at mobile widths is another chance to improve our testing tooling. Here is the incremental approach that we used to add mobile testing helpers.

Since the Capybara library drives the underlying tests, Minitest also has the same syntax.

We can write component tests with any language or framework, but the most popular ones are probably Cucumber and Capybara.

The nice thing about partial templates is that templates are unit-testable with View specs (or similarly in Minitest) and the rendered output can even be verified using Capybara matchers.

To piggyback: This would be a type of browser test, so you would want to use something like Cypress (https://github.com/testdouble/cypress-rails) or Capybara (https://github.com/teamcapybara/capybara). RSpec has a good integration with Capybara. Cypress is JS-based so it will require some additional config.

When you write a system test (or, as we prefer, a system spec) with Ruby on Rails, you're exercising the whole stack from the point of view of the user. So, naturally, you have to do things like make sure that certain elements are on the page and work as you expect when you click on then, type in them, and drag them around. Capybara works exceedingly well for this, giving you a lovely API for querying HTML.