Erroneous 'open' statement simplification

[saul]

I have the following code in an F# file that uses SQL:

open System
open System.Data // "System." is marked as unnecessary
open System.Data.SqlClient // "System.Data." is marked as unnecessary

Expected behavior

Open statements should should never be simplified.

Actual behavior

Namespace is simplified, resulting in:

FS0893: This declaration opens the namespace or module 'System.Data.SqlClient' through a partially qualified path. Adjust the code to use the full path of the namespace. This change will make your code more robust as new constructs are added to the F# and CLI libraries.

Known workarounds

Ignore the simplification

[saul]

Whoever gets around to looking at this - it's worth pointing out that there is a very similar bug with namespace statements:

namespace Foo.Bar

open Foo

then the Foo in the namespace statement is marked as being unnecessary - the code fixer tries to simplify the namespace statement!

[vasily-kirichenko]

Unacceptable. Just unacceptable :)

[TIHan]

@saul could you provide a full sample or sample project?

[cartermp]

@saul with the following class library project I don't see what you're reporting:

namespace Testy

open System
open System.Data
open System.Data.SqlClient

module Foo =
    let f() =
        use conn = new SqlConnection()
        ()

System and System.Data are greyed out, but I would expect that. No option to simplify names (if I turn on the feature).

[saul]

Of course because they aren’t being used... try using something from System and System.Data.

[cartermp]

Works for me:

If I fully qualify, then I get the suggestion to remove the unused namespace, but that's it. No option to simplify a namespace.

[vasily-kirichenko]

@cartermp have you turned on the feature?

[cartermp]

Yes, it's on.

No option to simplify names (if I turn on the feature).

[vasily-kirichenko]

I can reproduce it on 15.5 preview 5

[vasily-kirichenko]

Fixed in #4068

[TIHan]

I was able to reproduce. When you turn on the feature, it doesn't immediately reflect. You have to close the window and re-open.