"Debug Subtest At Cursor" is broken

[firelizzard18]

Original report from @leandrosa:

Today I notice that the "debug subtest" is not working too. Before we could select the subtest command and put the name of the subtest(table-driven test) to debug it isolated. But now, its stopped to work.

There is an exception in the command handler below because args is undefined when the user triggers the command via vscode's command pallet.

vscode-go/extension/src/goTest.ts

Lines 103 to 105 in eeb3c24

	const currentTestFunctions = args.functionName
	? testFunctions.filter((func) => func.name === args.functionName)
	: testFunctions.filter((func) => func.range.contains(editor.selection.start));

[gopherbot]

Change https://go.dev/cl/657395 mentions this issue: extension/src/goTest: fix debug subtest at cursor