HtmlUnit/htmlunit

❤️ Replace the Rhino based JavaScript engine ❤️

rbri opened this issue · 7 comments

rbri commented

HtmlUnit uses a slightly modified version of the latest code of the Rhino (https://github.com/mozilla/rhino) js engine. During the years we also provide many fixes and improvements to the project (https://github.com/mozilla/rhino/commits/master/?author=rbri). Adding support for more modern js syntax is really hard, because Rhino tries to be backward compatible (for good reasons) (eg. mozilla/rhino#1431).

Therefore i like to try to switch to another javascript engine.

This will require time and effort - you can support this via

Will use this issue to inform about the progress.

skyhirider commented

Which engine(s) are you considering?

And will you implement via ports & adapters where users will be able to choose which engine to use, or will you completely switch to a new one?

Would be interesting to be able to hot swap the engine.

For example, if I know a page is not working correctly with Rhino (live scrolling for example), I could hot swap to the other js engine before loading the page, do what I need to do and then hot swap back.

Would allow for slow rollout as people would start using the new engine more and more as you work to refactor and integrate it while adding more js features and fixing issues.

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arjantijms commented

Would it be an option to add a transpiler of some sort, to support newer js syntax?

kincsescsaba commented

Would it be an option to add a transpiler of some sort, to support newer js syntax?

You can add a ScriptPreProcessor to do the transpilation to ES5: https://gist.github.com/kincsescsaba/a7f1b236c1be91e1529a9af8e31e4357

rbri commented

This transpiler idea was suggested already in another issue, maybe i can add that feature based on the gist. There is also a special babel configuration for Rhino, this might also be helpful for that.

At the moment i more focused on Rhino because so many things are going on, the project really moves forward and there is some hope to get more major features done soon.

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rbri commented

At the moment the rhino project moves really fast - there is hope for spread and also class support. Therefore i like to stay with rhino and see how it processes during the next months.
Check the release notes to get an idea what has changed during the last months.

ptrthomas commented

@rbri just curious if you have looked at https://github.com/roastedroot/quickjs4j
also out of academic interest when you say spread support, can you point me to a discussion etc. to get an idea of what the current gaps are

rbri commented

@ptrthomas currently on vacation, will come back to this in a week

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