[Bug] Parsing failure when tasks.json contains comments

[lonix1]

Environment data

latest of everything
linux
sdk: 5.0.102
vscode: 1.52.1
c# extension: 1.23.8

Problem

When opening a project, I get a popup error:

Failed to parse tasks.json file

Sample

This is .vscode/tasks.json which is a jsonc file:

// this comment is allowed
{
  // this comment is allowed
  "version": "2.0.0",
  "tasks": [
    {
      // this comment is allowed
      "label": "run",
      "type": "process",
      "command": "dotnet",             // this comment is allowed
      "args": [
        "run",
        "--project",
        "${workspaceFolder}/src/Foo/Foo.csproj",
        //"--launch-profile", "Production",           // <<<<<<<<<< THIS IS THE PROBLEM
      ],
    },
  ],
  // this comment is allowed
}

The comment inside the args array is the problem. When removed, there is no error.

[JoeRobich]

@lonix1 Sorry we didn't respond to this issue earlier. I believe it is VS Code sending your this error popup. I think you will want to report this issue at https://github.com/microsoft/vscode/issues

[lonix1]

Thanks I've done that.

[lonix1]

Apparently they don't think it's a vscode issue.

One more thing, the error popup shows this:

Failed to parse tasks.json file
Source: C# (Extension) <----------

Any thoughts?

[spencer741]

+1 I am still seeing this issue on latest omnisharp.

Proof that it is the omnisharp extension: If you restart the omnisharp server, the error message pops up again.

@JoeRobich

[lonix1]

UPDATE

I'm now using the new c# extension (v2+).

Unlike in the bug reproduction above, I no longer have a comment in an "args" array, but the problem remains because when I open the workspace I get the same error:

Failed to parse tasks.json file
Source: C# (Extension)

I tracked down the problem:

// allowed
{
  // allowed
  "version": "2.0.0",         // allowed
  "tasks": [

    // allowed
    {
      "label":   "foo",       // ERROR!  <<<<<<<<<<<<<<<<<<<
      "type":    "shell",
      "command": "true",
      // ERROR!                          <<<<<<<<<<<<<<<<<<<
    },

  ],
}
// allowed

Any comment inside a task hash will trigger this problem. (So actually it's worse than before, because this didn't happen before.)

So the parser doesn't fully respect jsonc: it allows trailing commas, and comments in most places, just not inside the task hashes.

Our tasks file (like most of our code) is heavily commented, so this is a real nuisance, and has been for years.

@jasonmalinowski I hope it's ok that I hijacked my own issue with the new reproduction details? An info you need from me just let me know.

[jasonmalinowski]

@lonix1 Fine in this case, since it does look to be the same issue.