Cypress: Provide an option to disable test files preprocessing.

[kamituel]

• Operating System: Mac
• Cypress Version: 0.19.2
• Browser/Browser Version: Chrome 58

Are you requesting a feature or reporting a bug?

Feature.

Current behavior:

Cypress preprocesses test JavaScript files (using Babel / Browserify). I'd like to use ClojureScript to write tests, which means using a compiler (based on Google Closure) to obtain a final test JS file. However, Google Closure produces JS files that expect this to be set when invoked outside of a function (in the global context). Current Cypress' preprocessing makes this undefined, which breaks code compiled using Google Closure. I don't know of any obvious workaround for this.

Expected behavior:

To be able to disable test JS files preprocessing, so that I can use ClojureScript / Google Closure compiler.

How to reproduce the current behavior:

1. Create a ClojureScript test namespace:

(ns st.general)

(js/describe "General" (fn []
  (js/it "Page title" (fn []
    (js/cy.visit "http://localhost:80")
    (.should (js/cy.title) "equal" "Page Title")))))

1. Compile it using ClojureScript compiler to cypress/integration/test.js

2. Run this test using Cypress. It will hang for a long time, and eventually produce an error that can be tracked down to this being unset.

Test code:

n/a

Additional Info (images, notes, stack traces, etc)

This has been briefly discussed on Gitter on June 9th around 1:30 PM UTC.

[vemv]

Any plan on making this possible?

ClojureScript has a mature (6+ years), large, enthusiastic community without a lot of robust available options in the integration-testing space.

cypress could fill that gap!

@kamituel , could you get this to work?

[kamituel]

without a lot of robust available options in the integration-testing space

selenium-java :)

@kamituel , could you get this to work?

Nope. For now I settled on using JavaScript basically. However, I'm using Cypress to test a proof-of-concept project we're working on. If we were to start using Cypress for our main web app, ClojureScript support would be necessary.

I discussed it briefly with Cypress' team on Gitter a while back and they weren't opposed to this idea. It's probably just not high on a priority list.

Having that said, Cypress 1.0.0 which is likely just around the corner, will be open source, and then we'll be able to tackle this ourselves.

[chrisbreiding]

We're currently working on a generic plugin system for preprocessing spec files that will solve this issue. You'll be able to create a plugin that integrates with the Cypress preprocessing pipeline. It will allow you to disable the default preprocessing, or you could create a ClojureScript preprocessor that transpiles your ClojureScript tests and lets the app know to re-run.

This should be released within the next month or so. If it doesn't make it into 1.0.0, it will be in 1.1.0.

[vemv]

Sounding awesome!

Good luck with the development and release of Cypress!

Cheers - Victor

[kamituel]

@chrisbreiding
Thanks, that sounds great.

[brian-mann]

Fixed by https://github.com/cypress-io/cypress/pull/888.

[brian-mann]

Fixed in 1.1.0.

[chrisbreiding]

With the plugins API now released, you can create a ClojureScript preprocessor or you can essentially disable preprocessing by using the watch preprocessor.