Node.js support

[tlightsky]

can dirac connect to my repl in nodejs(cljs)

[darwin]

I believe all pieces for first-class nodejs support are in place:

1. you run your nREPL server, with Dirac Agent
2. you add Dirac runtime into your nodejs app
3. you can use Dirac DevTools to debug your nodejs app[1]

#3 is very recent addition to DevTools, it should work, but Chrome devs are still fixing bugs.
#2 Dirac runtime should not care if it runs in browser context or nodejs context (I believe)

I have never tried this setup myself. It would be cool to create a sample project for nodejs app working with Dirac. Unfortunately I'm not going to spend time on this task ATM.

[1] https://medium.com/@paul_irish/debugging-node-js-nightlies-with-chrome-devtools-7c4a1b95ae27

[tlightsky]

thanks, I shall upgrade my node to new version first

[fonghou]

I just tried it in node 7.4.0 and dirac 1.0.0.

Devtool console prints out a message "Feature :repl cannot be installed. Unsupported browser ."

Here is a screenshot with more details.

My guess is that node doesn't has certain browser properties that dirac depends on (btw, cljs devtools also failed to install, above is with cljs devtools feature disabled)

[darwin]

we will have to relax this condition:

dirac/src/runtime/dirac/runtime/repl.cljs

Line 20 in e92a3ab

(and (ua/isChrome) (ua/isVersionOrHigher 47))) ; Chrome 47+

you might try to patch this function and then call dirac.runtime/install! by hand

[fonghou]

@darwin Thanks for the hint!

Hit another dependence on js/document. It looks like part of dirac client code has to be injected into chrome-devtools://devtools/bundled/inspector.html ?

Screenshot

[darwin]

ok, set *boostrapped?* to true prior install! call:

dirac/src/runtime/dirac/runtime/bootstrap.cljs

Line 7 in e92a3ab

(def ^:dynamic *boostrapped?* false)

after install call (brepl/bootstrap) by hand

let's see how far you can get...

[darwin]

ah, scratch my previous comment, I don't have time to reply now. Maybe you could figure out another way how to implement install! on your own. Maybe set! *boostrapped?* and *installed? to true and call (brepl/bootstrap)

[fonghou]

That didn't allow me to do what you suggested. Instead, I tried to comment out

dirac/src/runtime/dirac/runtime/bootstrap.cljs

Line 57 in e92a3ab

(call-after-document-finished-loading boostrap-if-needed! 0)))

then call (boostrap-if-needed!) by hand. No error in js console, but dirac console won't start after clicking the button on toolbar.

[darwin]

I was able to make it work here on my Mac. But it will require some deeper changes. I'm pretty confident I will be able to provide an example project configuration by the end of this weekend.

[fonghou]

That's awesome! Looking forward to try it!

Really appreciate your time and effort in developing dirac!

[darwin]

Try to upgrade to v1.1.0, basic support should be in place:
https://github.com/binaryage/dirac/releases/tag/v1.1.0

[fonghou]

Hi @darwin, I did a quick test (not setting up external source-map serving yet). Basic feature works. Just want to let you know a few differences.

1. you said in the doc, REPL eval only works at debugger point. However, my dirac repl seems working even not at debugger point.

2. i got CLJS DevTools errors when Dirac hits a debugger point.

[darwin]

Ok, thanks for the feedback. I'm not sure about that REPL eval. Could have been some glitch in my setup.

That CLJS DevTools Error is unrelated to this issue. It is not even CLJS devtools bug. You are likely to see similar stack trace event without cljs-devtools. It looks to me that Promesa throws when someone wants to print its value via IPrintWithWriter protocol.

[fonghou]

Yes, you are right. That's an issue from promesa. will report it there (i did a local fix that works).

Thanks again for your help!

[darwin]

Released in v1.1.0.

I don't hear any complaints. Feel free to reopen in case of bug reports.

[fonghou]

This is with dirac node support. Getting

Internal Dirac Error Request Debugger.getPossibleBreakpoints failed. {"code":-32601,"message":"'Debugger.getPossibleBreakpoints' wasn't found"}

It seems triggered asynchronously, as well as when stepping in debugger. Please see sreenshot attached.

[darwin]

This looks like out-of-sync debugger protocol between Devtools and Node.js.

In case of similar troubles, you should be using nightly builds of node.js:
https://github.com/binaryage/dirac/blob/master/docs/node.md#nodejs-version

[fonghou]

Yes, that seems the case. Thanks!