View, explore & add variables when debugging R shiny app in Positron

[AlastairCSmith]

I'm loving Positron and wish to move from Rstudio to using it as my main IDE however I can't do so yet due to not being able to solve the following issue. Can anyone help with this, maybe I've missed something obvious?

In Positron I'm able to launch my R shiny app and enter a break point defined by 'browser()' but I do not see how to access/explore the local variables in debug mode?

In Rstudio this is very simple via the view() function and 'Environment' panel, plus importantly any new variables I create in debug mode are easily explorable in this way. How can I access the same functionality in Positron?

[DavisVaughan]

The Debug Variables pane up in the top left is the correct place to look for variables in the current debug frame.

This also responds to any variables you create in the Console while in debug mode (it should refresh if you type x <- 1 in the Console).

It is limited though, i.e. you can see how it just reports <reactivevalues> for rv, and does not let you "dig into" the object there in the Debug Variables pane.

To further dig into the object, right now you should just use the Console like it looks like you've already done. You printed out rv there in the Console and you can see what it looks like at the current point in time. You can run other code here to inspect the details of rv as required.

It is also worth noting that the main Variables pane up in the top right will always reflect the Global Environment, and not the environment of the current debug frame, so that is not where you should be looking when debugging.

[AlastairCSmith]

Thank you Davis for taking the time to respond so thoroughly it is much appreciated.

[immanuelazn]

If possible, I would like to put a request for expanding variables in "Debug Variables". I work a lot with S3 objects, and it is a little disabling not being able to see changes to objects when debugging. I can always use the debug console, but this also is more difficult if I haven't implemented print S3 methods for these classes. A json/dict style view makes it much easier.

[juliasilge]

Thank you for this feedback! I have opened #8939 to track and prioritize this feature request.

[arenaux-xlra]

I completely agree with @AlastairCSmith that there is something a bit off when using the debug mode in Positron, and I’d like to make a related request to the developers.

In VSCode, the Data Wrangler plugin (unfortunately not available in Positron) allows opening dataframes directly via a right-click on any variable present in the "Debug Variables" panel, using the "View dataframe in data viewer" option. This is extremely convenient and works for both Python and R.

It would be very helpful, for consistency and usability, to have the same kind of shortcut in Positron’s "Variables" panel when in debug mode. A simple "click to view" action, similar to what’s already available for R objects, would go a long way.

At the moment, the workaround is to run View(variable) manually in the console, which opens it in the Positron data viewer, but that only works in R it seems... (?)
For Python, I did not find an equivalent shortcut. The only option is to print a subset of the dataframe in the console, which is far from ideal...

[juliasilge]

Thank you for this report! 🙌

• Python: "View Value in Data Viewer" debug button does not work #5659 is tracking us improving the UI in the debug variables for Python; I don't think there is currently a workaround since you can't step through interactive debugging in the console for Python yet.
• I opened Integrate Data Explorer into R debugger #8822 to track and prioritize the feature request for R.

Please add any additional info on your use case, if you think that makes sense!