postLaunchTask would be very useful

[trstringer]

Currently we have the ability to specify a preLaunchTask in launch.json configurations. This is extremely helpful in running a task that should kick off before launch.

Conversely, there could be post launch tasks that would be helpful to automate their execution. An example of a post launch task would be to, after the launch of the application, open a browser window with a specific URL to the current application.

In summary, a postLaunchTask would be helpful as preLaunchTask is.

[theBull]

@weinand any updates on the progress of the postLaunchTask feature? Or perhaps, do you know of any existing extensions that can perform a similar function?

[isidorn]

We accept PRs that fix this.
Here's a code pointer on how preLaunchTask is implemented
https://github.com/Microsoft/vscode/blob/master/src/vs/workbench/parts/debug/electron-browser/debugService.ts#L892

[cleidigh]

@tstringer
@isidorn
I will pick this up for December...

[markm77]

Is it possible to support this for compound launch configs - so that, for example, once all my node-js processes are up, inject some scenario data or clear the DB from previous experiment....

[isidorn]

@trstringer why did you close this? I think this is still an appropraite feature request?
We currently support a postDebugTask which runs after the whole debugging stopped, a postLaunchTask is still not supported as far as I know.

[trstringer]

I wasn't sure of the timeline, it was almost a year stale at this point. I'll reopen!

[robofearth]

Was looking for this and stumbled on this thread (created 2016!!). Definitely would be handy to auto-initiate a task after a debug session has started running. 👍👍

Edit: To clarify, not after a debug session has ended, eg postDebugTask, but after the debug session started and is still active

[xPathin]

I also stumbled on this because I stumbled onto a problem concerning this.
However i think that the lifecycle should be a bit different and more how PostDebug works, which executes before the debugger disconnects (after the debug session).
What i would find much cooler is if we could differentiate between debug and launch and have pre/post tasks for both instances.

PreLaunchTask -> Executes before launch, doesn't care about debugger (exactly how it is now)
PreDebugTask -> Executes right before the debugger attaches
PostLaunchTask -> Executes if launch action aborted or otherwise finished, doesnt care if debugger is attached
PostDebugTask -> Launches after debugger detaches

I wonder why it is not implemented this way and there is only PreLaunch and PostDebug, there must be a bigger reason on this. Does someone have more insight?

[hwmaier]

Likewise, stumbled across this too while looking for something like "postLaunchTask" which allows for example to launch either a telnet client in a terminal or JLinkRTTClient to connect a terminal to a debugging session.

[roblourens]

Since the original use-case mentions launching a browser after a server has started, I wonder whether https://code.visualstudio.com/docs/editor/debugging#_automatically-open-a-uri-when-debugging-a-server-program is sufficient for this? Does anyone have a scenario that can't be covered with that feature?

[vscodenpa]

This issue has been closed automatically because it needs more information and has not had recent activity. See also our issue reporting guidelines.

Happy Coding!

[adellhk]

@roblourens in our usecase we are generating some code during the build step and we want to then bundle the generated code. It would be ideal to run the tasks that bundle the generated code as a postLaunchTask. For now we are just manually running the tasks after the build is done.

[roblourens]

Not clear to me why that should be a postLaunchTask rather than part of the preLaunchTask

[adellhk]

We're using VS Code and a well-supported VS-code extension to deploy code to Roku.

I want to bundle the files generated into out/.roku-deploy-staging after roku-deploy has created them with a hypothetical postLaunchTask after the launch task that we invoked with F5 completes.

[hwmaier]

Does anyone have a scenario that can't be covered with that feature?

Yes, Refer to my comment above. With debuggers for embedded targets like the JLink Cortex ARM debugger you cannot use the postLaunch task because the debugger is not active yet. Certain things can only be done after the debugger has been started and at present those cannot be automated due to a missing postLaunchTask.

[roblourens]

@adellhk I still don't understand why it makes sense to bundle or deploy these files after debugging has already started.

@hwmaier thanks for the explanation. As a workaround it would probably be easy for someone to write an extension that essentially implements a postLaunchTask.

[cHemingway]

I also have the same scenario as @hwmaier , also in embedded.
I quite often want to attach a program (e.g. a terminal, or J-Link RTT Viewer) to a running debugger, but (without modifying the program) it won't work unless the debugger process has been started.
For this use case, postLaunchTask would be very useful

[roblourens]

Thanks. One reason I'm still hesitant to put this in vscode is that "postLaunch" is hard to define. There are multiple points in the debug setup flow that could be considered "postLaunch", and even then, there is no guarantee that the debuggee is in the right state that you need it in to be able to do what you want to do with it, and so I think a general "postLaunchTask" isn't the right direction.

Instead you might try to write an extension that can do what you want. For an example, you can see what we did for the serverReadyAction feature with this extension:

vscode/extensions/debug-server-ready/src/extension.ts

Line 301 in 0e9e351

const listener = vscode.debug.onDidStartDebugSession(session => {

We were solving the same problem there - for example, just because the web server process has started and a debugger has attached, it doesn't mean that the server is ready to handle requests, so we need to watch for a custom output string to know when the web server is ready.