Foundry debugger modify value during execution

[publicqi]

Component

Forge

Describe the feature you would like

Background

I am working on some small new features on forge debugger. I added a new "control" pane to display misc infos. There's a section called "Command", and I want the user be able to interact with the debugger. For example, it will now show input buffer (i.e. number + action)

New feature discussion

Currently forge debugger executes a transaction and collect all execution steps and display them. It lacks dynamic modifying values.

Although this requires a big refactor, it will be easier for debugging for special needs. One can simulate different scenarios and edge cases without altering the source code or redeploying contracts or re-execute with different params.

For refactoring, I think we have two paths to go. One is to change the debugger to a step-wise style, which does not execute the transaction at once. The other is to use an inspector containing an (address, pc, modification) tuple, and when a modification command is input, the transaction will be re-executed.

Additional context

No response

[iFrostizz]

Before doing yet another refactor of the debugger, we should probably just support the DAP for good. Related #5784

[zerosnacks]

Hi @publicqi thanks for your proposal!

Given that the current state of external debuggers is still quite early I feel like it definitely still makes sense to iterate on the current version of the debugger and I'm supportive of your proposal.

If I understand you correctly this is something you would like to contribute? If so, let me know if you have any questions or run into any blockers.

[publicqi]

Breaking down into the following tasks.

• UI change (add control pane) also feat(debugger): display gasleft, totalGasUsed and number of subcalls #8784
• Breakpoint command
• Watchpoint command (need an inspector for this)
• Modify value during execution