Theia: 'Run Selected Text' is not working when a task is stopped

[RomanNikitenko]

Description

'Run Selected Text' action is not working when current terminal widget is completed task widget.

Reproduction Steps

1. Run any task
2. Stop the task
3. Select a command and use Run Selected Text action

OS and Theia version:
Ubuntu 18.04.1
Theia: ced3f90a3b1ebf6fcfaf5a62e082dcdfa1f0304c

Diagnostics:
I guess Run Selected Text action tries to use stopped task as current terminal widget.

[elaihau]

I did some investigation, and found an intesting behavior in vs code: "Run Selected text" simply echos the selected text in the current terminal which has one task actively running, instead of running the selected text as a command (See the attached GIF). Is it the correct behavior ?

In my opninion, the "selected text" should always be run in an interactive terminal, no exceptions. If there is a task running in the current terminal, we should find an interactive terminal, or create an interactive terminal to execute the selected text as a command.

What do you think? @RomanNikitenko @vince-fugnitto @akosyakov @eclipse-theia/task-extension

[vince-fugnitto]

In my opinion, the "selected text" should always be run in an interactive terminal, no exceptions.

I agree, I find it odd that vscode would use a busy terminal to display output of “run selected text”. In my opinion, the output would be lost in all the noise of a task which is currently under execution. I think we should opt for the simplest solution which is to look for an idle interactive terminal to run the text or create a terminal if none exist.

[RomanNikitenko]

In my opninion, the "selected text" should always be run in an interactive terminal, no exceptions. If there is a task running in the current terminal, we should find an interactive terminal, or create an interactive terminal to execute the selected text as a command.

Agree.
For 'Run Selected Text' we should use:

• an idle terminal, if it exists
• create a terminal if it does not exist

[elaihau]

would this solution work for you?

• "Run selected text" runs the selected string as a command in interactive terminals
• If no terminals are interactive, run it in a new interactive terminal. Please note, in the GIF below, the terminal that ran "long running task" wasn't an interactive terminal and therefore we created a new one.

[akosyakov]

What it a definition of the idle terminal If i don't know about tasks?

[elaihau]

What it a definition of the idle terminal If i don't know about tasks?

@akosyakov
as you know, "idle" is not a property of the terminal. so we have no idea if a terminal is idle.

that's why I proposed the solution of "only running selected text in an interactive terminal"

and we could use terminalWidget.hasRunningProcesses() to check if an interactive terminal is busy.

What do you think?

[akosyakov]

and we could use terminalWidget.hasRunningProcesses() to check if an interactive terminal is busy.

Terminal which does not run any task also has a running process (shell). How is it related to terminal be interactive? How do you define terminal interactive? That it can accept a user input? How could you check that a terminal process can accept a user input?

[akosyakov]

• I don't really think terminal can tell a user whether it is interactive or not. Whether script running in a terminal can accept user input or not it is a property of a script, not a terminal process. And since terminals are only operating process streams it is abstracted away from concrete scripts. I would say it is responsibility of a terminal client to know whether something running in the terminal is interactive or not, i.e. a task can be interactive.
• I am not sure what interactive is correct term even for tasks. How do you know whether a concrete task needs user input or not?
• So if we cannot use interactive, we are back to idle/busy concept. For this concept similarly as for interactive we cannot know it for terminal, but for a task is more clear. A task is either still running or finished.
• We have busy concept already for other widgets in Theia: monaco editors and trees. In the editor the peek widget can be busy for example while resolving references and in the tree a concrete node while it is resolving child nodes. In both cases there is API allowing to change busy state, so maybe we add something similar to terminal:

export interface TerminalWidget {
   busy: boolean;
   readonly onDidChangeBusy: Event<boolean>;
}

• Whenever a task extension is running a task in the terminal it should set busy state and then it is done remove it.
• Having busy state we can implement this issue following such logic:
  
  
  
  • if the current terminal is not busy, run command in it
  
  
  • it it is busy, create a new terminal
  
  
  • I don't think revealing some random hidden terminal to run a task is a good idea.
  
  
• I think https://github.com/eclipse-theia/theia/issues/7323#issuecomment-601060436 is most appropriate.

[akosyakov]

Or maybe we can introduce something like TerminalType with System and User kind, defaults to User. System kind means that a terminal was created by a product for some reasons and cannot be used to run random user scripts, e.g. for tasks. Then for this issue we will check whether a current terminal is User terminal and if not create a new User terminal. In both cases terminals can be interactive, i.e. if a task requires some input from a user.

I actually like it more, since it looks like terminals running task should disallow running a random user program and busy won't help with it. But System kind can resolve both issues.

[akosyakov]

terminal.kind will be introduced in https://github.com/eclipse-theia/theia/pull/7260. After it merged, this PR should be fixable by respecting only user terminals.