• VSCode Version:1,35
• OS Version: Ubuntu 19.04 x64

Steps to Reproduce:

• Launch a new, empty instance of VSCode
• Create (but don't save) a new file (Untitled-1)
• Set the language mode for the file to JavaScript (to enable the Typescript/Javascript language feature extension)
• In the new file, type an arrow function with an unused parameter:

a => 3

Move cursor over a and from the "lightbulb" code actions, pick remove declaration from 'a' - it works;

() => 3

Now pick another code action: add braces to arrow function and nothing happens. Developer logs show:

Save the file (Untitled-1.js). Run the same code action again and it works:

() => {
	return 3;
}