visualstudio open namespace codefix has wrong indentation in some cases

[smoothdeveloper]

In indented context, the open namespace code fix puts the declaration at wrong indentation level.

It doesn't always affect the code, but when there are type extensions, it breaks it.

module Foo =
  open System

  type DateTime with
    member x.X() = ()

  let a () =
    let t = Task.Factory.StartNew(fun () -> 1) // use the code fix on Task
    ()

Related information

VS2019 16.8

[smoothdeveloper]

Another case:

[<AutoOpen>] // will insert after the attribute
module Foo2 =
  // would prefer here if "Always place open statements at the top level" is unchecked
  let a () =
    let t = Task.Factory.StartNew(fun () -> 1) // use the code fix on Task
    ()

Currently Here it introduces open ... on a new line just after the attribute making the code invalid.

Given the settings, I'd prefer open ... to land on a new line just above let a () =

[smoothdeveloper]

@vzarytovskii/@cartermp do you know if there are tests for this code fix, is it easy to add one for each cases?

[cartermp]

This seems like a bug in the tryfindinsertioncontext routine here: https://github.com/dotnet/fsharp/blob/8b361cfc6eecbccfb2dc625faa7ff66e7e621be5/src/fsharp/service/ServiceAssemblyContent.fs#L994

It's complicated code unfortunately. I'm not sure if it's under test. We have decent testing for the analysis part, but not the insertion part.

[psfinaki]

Okay this still reproduces the "Always place open statements at the top level" off.

[psfinaki]

Fixed partially as of now - the code fix doesn't break the code anymore but the location of the inserted code is still not precise.