Node-RED Breakpoints

Core Development Feature Requests
1

Hello everyone,
I was talking with a friend about how we can improve the debugging process of developing a Flow using Node-RED and he came with the idea of having breakpoints like the ones we have in the most famous IDEs.
Wouldn't be nice to have such a thing? Specially if we could manipulate the msg during a break event.

2

Hi Tiago,

I think this is already on the long-term planning. See this Trello item.

Kind regards,
Bart Butenaers

3

Hi,

although not exactly what you want, this may help you until the mentioned Trello item is implemented:

At our company when developing new nodes or extending existing nodes we debug somehow like this:

  • https://github.com/Microsoft/vscode-recipes/tree/master/nodemon

  • Instead of "attach" I use the following launch.json:

      "version": "0.2.0",
  "configurations": [
      {
          "name": "Launch node-red via nodemon",
          "type": "node",
          "request": "launch",
          "runtimeExecutable": "nodemon",
          "program": "/usr/lib/node_modules/node-red/red.js",
          "restart": true,
          "console": "integratedTerminal",
          "internalConsoleOptions": "neverOpen"
      }
  ]

  • find the files of the nodes you are using, open them (or the folder) in vscode.

  • add Breakpoints

  • now when pressing the green arrow for debugging node-red will start via nodemon

  • happy debugging

Best regards
Lars

2 Likes
4

I wonder if this flow debugger made into the next release.

5

Hi @fangzhu,
As you can see here the Pluggable Message Routing is still on the roadmap, but not in the 1.0 release. Moreover when that feature ever becomes available, I assume somebody still has to develop some kind of Node-RED debugger on (using the pluggable message routing)?
Bart

6

Thanks for quick response.

What I wanted is more like a break point that can temporary stop the flow process at some node so that developer can confirm the intermediate result, such as context data, database data at that point etc.

I am looking forward to this wonderful feature in the future.

7

@fangzhu
A little something I've made to simulate breakpoints on Node-RED nodes.
Very alpha stage, but works for my needs.
node-red-contrib-msg-tracer

3 Likes
8

Hi Alon (@AlonAmiraabluedragon),
Welcome to the forum!
I had already made some advertisement for your node some time ago:

I'm very impressed by your work!!!

2 Likes
9

Thanks, I hope you find it useful!
Though I have to admit @knolleary was right in his comment, I did end up using private APIs and "dirty" tricks as mentioned, I verified compatibility with Node-RED 0.20 -> 1.0
but the ability to debug, having "breakpoints", step-by-step, was something I missed greatly while having to maintain complex flows, so for me it's still better than nothing.

10

Hi @AlonAmiraabluedragon perhaps if you are still interested, you could discuss with Nick & Dave & come to an agreement on implementation then you could contribute to core?

It would take a load off these 2 guys (who I can only imagine are overloaded with the breakneck pace of development) - then everyone would benefit from your contribution by it being built in to core.

Would be good to see such a prominent feature take shape.

11

A flow debugger is on the roadmap.

It is top of the list once we get the pluggable message router feature in. Doing anything before that would be premature.

1 Like
12

Absolutely Nick however I don't think I was clear & you might not have caught my inference. I was inferring the op could assist in the overall solution (including the message routing). As you said in the other thread, a missed opportunity that could bring effort directed at helping deliver the backlog.

Just trying to help & not meaning to step on any toes.

3 Likes