problem matcher that clears only for changed files

[nevir]

I have a watch task that runs various per-file checks (lint, appropriate tests, etc). When it starts up, it runs those checks for all files in the project. Thereafter, it only runs checks on files that change.

For the most part, it works great; but the one limitation I'm running into is that all problems for a particular matcher are cleared on a run.

For example:

1. I boot up the watch task, and there are problems on foo.js and bar.js. The problem matcher picks up on all of these.

2. I make a change to foo.js:

   a. The watch task re-runs checks for just foo.js.
   b. The problem matcher notices that a re-run has occurred, and blows away all problems of that type
   c. Only problems for foo.js are listed, even though bar.js still has issues.

I'd like to avoid building a language server or plugin for this if I can (the watch task is very useful to non VS code users on the team; and problem matchers are wonderfully simple).

Or maybe we could have an option for only clearing problems for files that have changed (or that match a particular expression?)

[Ciantic]

I'm seeing this behavior:

When I have problem watcher in watching task, it clears all warnings when I change editor (not save it), so each time I edit file all warnings disappear, but as soon as I save (the watching task lists the warnings again) they re-appear.

This makes working with problem matcher view difficult, because the warnings / errors disappear all the time as I edit the file even though the output has not been re-run because I have not saved.

In my opinion on watching task the warnings should cleared only when the console output changes. Right now it's easier me to look at the output console than to problem matcher view because it clears itself out all the time.

[dbaeumer]

@nevir how did you configure the task. Is if configured as a watching task then this should not happened (e.g does it have a "watching" property). If not the task framework always assume that all files are validated and all valid errors are rereported. Otherwise errors would never be cleared in cases where you have inter file dependencies.

@Ciantic I assume that your problem is different. If I look at your task configuration here #8304 then you use "typescript" as the problem owner. So as soon as you type in a TS file your errors will be overridden since the typescript language server uses "typescript" as an owner as well. Have you tried to give them a different owner.

[Ciantic]

If you have problem with problem matcher clearing itself out every time editor changes, remember to put a unique string in the "owner" property of all problem matchers, e.g.

"problemMatcher": [
    {
        "owner": "SOMEUNIQUESTRING",
        // ...
    }
]

Forgetting this, can cause weird problems with multiple matchers.

[nevir]

@nevir how did you configure the task. Is if configured as a watching task then this should not happened (e.g does it have a "watching" property). If not the task framework always assume that all files are validated and all valid errors are rereported. Otherwise errors would never be cleared in cases where you have inter file dependencies.

Yeah, I had it configured as a watch task. The difference here, I think, is that the task itself only ran against files that changed (rather than the entire project, as most watch tasks tend to, and VS Code seems to rightly assume)

[dbaeumer]

Keeping as a feature request to allow watching patterns on a per file bases.