Failure message from SetVariable request is not surfaced

[gjsjohnmurray]

Similar to #80452 but for the SetVariableRequest. The target environment of my debugger can only change a variable value at the stack level of the execution point, so I want to notify a user if they try to make a change when they have selected a different stack level.

VS Code version: Code 1.38.0 (3db7e09, 2019-09-03T21:49:13.459Z)
OS version: Windows_NT x64 10.0.17134

[isidorn]

I think you can just throw an error in setVariable and it should hopefully be nicely handled here
Did you try that? Does that not work?

[gjsjohnmurray]

I don't think I tried throwing an error. I expected it to respect the following in my DebugProtocol.SetVariableResponse reply:
{success: false, message: 'Unable to set that value', ... }

`

[isidorn]

Unfortunetely I do not yet respect the success field. For now I suggest you try throwing an error in this case.
In the future I might handle this case better

[gjsjohnmurray]

@isidorn I just tested this with the mock-debug sample but it didn't work.

In initializeRequest I added response.body.supportsSetVariable = true;

I added this:

    protected async setVariableRequest(response: DebugProtocol.SetVariableResponse, args: DebugProtocol.SetVariableArguments): Promise<void> {

		response.success = false;
		response.message = 'Not yet implemented';

		// Workaround for https://github.com/microsoft/vscode/issues/80464#issuecomment-530713561
		if (!response.success) {
			throw new Error(response.message);
		}

		this.sendResponse(response);
	}

I used the debugger to verify that my code was called when I tried changing a variable. But the error I throw didn't surface anywhere that I noticed.

[isidorn]

Can you please push your changes to a branch of mock debug so I simply clone it and try it out. Thanks a lot!

[gjsjohnmurray]

@isidorn I have prepared a branch at https://github.com/gjsjohnmurray/vscode-mock-debug/tree/show-80464 in which I always throw an error here in setVariableRequest, but don't see my message surface in the UI.