Scriptpoints

This extension can make breakpoints run JavaScript when hit. Just create a logpoint that begins with !, and the rest of the message is interpreted as JS. You can also start with !! to make execution pause when the scriptpoint is hit.

Environment

There are some useful functions available to your script:

• log(message: string) writes a line to the debug console.
• command(command: string, ...args) executes a VS Code command with the provided arguments.
• async evaluate(expression: string): string evaluates an expression in the context of the program being debugged and returns its value, the same as if you entered the expression in the watch panel.
• async memory(expression: string, bytes: number): string evaluates an expression and returns a chunk of memory beginning at the address of the value in base64. This only works in languages that support reading memory, like C++.

Note that evaluate() and memory() are async functions, because they need to use async APIs for communicating with the debugger. So you need to use them with await. For example, you should write log(await evaluate('myVariable')), as log(evaluate('myVariable')) will not work.

Uses

Scriptpoints let you write complex logging logic without needing to modify the code of the program you are debugging. For instance, you could use it to log a message if a list contains a particular item. Or you could log the square root of a variable instead of the variable itself. Or you could send 2D points to a command that adds them to a graph.

Scriptpoints work even for debuggers that have not implemented logpoint support, like vscode-cpptools. So, you can write !log(await evaluate('myVariable')) to get the equivalent of the logpoint {myVariable}.

Limitations

• If your program is paused and you step over a line of code that has a scriptpoint on it, execution will pause again at that scriptpoint.
• So far this extension has only been tested with C++ and JS. While it should work with any language, there could be bugs if those languages' debug adapters work differently from the ones that I tried.