Add codefix to convert C# using to F# open

vsintegration/src/FSharp.Editor/CodeFix/ConvertCSharpUsingToFSharpOpen.fs

@@ -0,0 +1,88 @@
+// Copyright (c) Microsoft Corporation.  All Rights Reserved.  See License.txt in the project root for license information.
+
+namespace Microsoft.VisualStudio.FSharp.Editor
+
+open System
+open System.Composition
+open System.Collections.Immutable
+
+open Microsoft.CodeAnalysis
+open Microsoft.CodeAnalysis.Text
+open Microsoft.CodeAnalysis.CodeFixes
+
+[<ExportCodeFixProvider(FSharpConstants.FSharpLanguageName, Name = "ConvertCSharpUsingToFSharpOpen"); Shared>]
+type internal FSharpConvertCSharpUsingToFSharpOpen
+    [<ImportingConstructor>]
+    (
+    ) =
+    inherit CodeFixProvider()
+
+    let fixableDiagnosticIds = set ["FS0039"; "FS0201"]
+    let usingLength = "using".Length
+
+    let isCSharpUsingShapeWithPos (context: CodeFixContext) (sourceText: SourceText) =
+        // Walk back until whitespace
+        let mutable pos = context.Span.Start - 1
+        let mutable ch = sourceText.[pos]
+        while pos > 0 && not(Char.IsWhiteSpace(ch)) do
+            pos <- pos - 1
+            ch <- sourceText.[pos]
+
+        // Walk back whitespace
+        ch <- sourceText.[pos]
+        while pos > 0 && Char.IsWhiteSpace(ch) do
+            pos <- pos - 1
+            ch <- sourceText.[pos]
+
+        // Take 'using' slice and don't forget that offset because computer math is annoying
+        let start = pos - usingLength + 1
+        let span = TextSpan(start, usingLength)
+        let slice = sourceText.GetSubText(span).ToString()
+        struct(slice = "using", start)
+
+    let registerCodeFix (context: CodeFixContext) (diagnostics: ImmutableArray<Diagnostic>)  (str: string) (span: TextSpan) =
+        let replacement =
+            let str = str.Replace("using", "open").Replace(";", "")
+            TextChange(span, str)
+        let title = SR.ConvertCSharpUsingToFSharpOpen()
+        let codeFix =
+            CodeFixHelpers.createTextChangeCodeFix(
+                title,
+                context,
+                (fun () -> asyncMaybe.Return [| replacement |]))
+        context.RegisterCodeFix(codeFix, diagnostics)
+
+    override _.FixableDiagnosticIds = Seq.toImmutableArray fixableDiagnosticIds
+
+    override _.RegisterCodeFixesAsync context =
+        asyncMaybe {
+            let diagnostics =
+                context.Diagnostics
+                |> Seq.filter (fun x -> fixableDiagnosticIds |> Set.contains x.Id)
+                |> Seq.toImmutableArray
+
+            do! Option.guard(diagnostics.Length > 0)
+
+            let! sourceText = context.Document.GetTextAsync(context.CancellationToken)
+
+            // TODO: handle single-line case?
+            let statementWithSemicolonSpan = TextSpan(context.Span.Start, context.Span.Length + 1)
+
+            do! Option.guard (sourceText.Length >= statementWithSemicolonSpan.End)
+
+            let statementWithSemicolon = sourceText.GetSubText(statementWithSemicolonSpan).ToString()
+
+            // Top of the file case -- entire line gets a diagnostic
+            if (statementWithSemicolon.StartsWith("using") && statementWithSemicolon.EndsWith(";")) then
+                registerCodeFix context diagnostics statementWithSemicolon statementWithSemicolonSpan
+            else
+                // Only the identifier being opened has a diagnostic, so we try to find the rest of the statement
+                let struct(isCSharpUsingShape, start) = isCSharpUsingShapeWithPos context sourceText
+                if isCSharpUsingShape then
+                    let len =  (context.Span.Start - start) + statementWithSemicolonSpan.Length
+                    let fullSpan = TextSpan(start, len)
+                    let str = sourceText.GetSubText(fullSpan).ToString()
+                    registerCodeFix context diagnostics str fullSpan
+        }
+        |> Async.Ignore
+        |> RoslynHelpers.StartAsyncUnitAsTask(context.CancellationToken) 

vsintegration/src/FSharp.Editor/FSharp.Editor.fsproj

@@ -95,6 +95,7 @@
     <Compile Include="CodeFix\AddInstanceMemberParameter.fs" />
     <Compile Include="CodeFix\AddTypeAnnotationToObjectOfIndeterminateType.fs" />
     <Compile Include="CodeFix\AddMissingRecToMutuallyRecFunctions.fs" />
+    <Compile Include="CodeFix\ConvertCSharpUsingToFSharpOpen.fs" />
     <Compile Include="CodeFix\ConvertCSharpLambdaToFSharpLambda.fs" />
     <Compile Include="CodeFix\MakeOuterBindingRecursive.fs" />
     <Compile Include="CodeFix\RemoveReturnOrYield.fs" />

vsintegration/src/FSharp.Editor/FSharp.Editor.resx

@@ -291,4 +291,7 @@
   <data name="UseTripleQuotedInterpolation" xml:space="preserve">
     <value>Use triple quoted string interpolation.</value>
   </data>
+  <data name="ConvertCSharpUsingToFSharpOpen" xml:space="preserve">
+    <value>Convert C# 'using' to F# 'open'</value>
+  </data>
 </root>

vsintegration/src/FSharp.Editor/xlf/FSharp.Editor.cs.xlf

@@ -27,6 +27,11 @@
         <target state="translated">Přidat anotaci typu</target>
         <note />
       </trans-unit>
+      <trans-unit id="ConvertCSharpUsingToFSharpOpen">
+        <source>Convert C# 'using' to F# 'open'</source>
+        <target state="new">Convert C# 'using' to F# 'open'</target>
+        <note />
+      </trans-unit>
       <trans-unit id="ConvertToAnonymousRecord">
         <source>Convert to Anonymous Record</source>
         <target state="translated">Převést na anonymní záznam</target>

vsintegration/src/FSharp.Editor/xlf/FSharp.Editor.de.xlf

@@ -27,6 +27,11 @@
         <target state="translated">Typanmerkung hinzufügen</target>
         <note />
       </trans-unit>
+      <trans-unit id="ConvertCSharpUsingToFSharpOpen">
+        <source>Convert C# 'using' to F# 'open'</source>
+        <target state="new">Convert C# 'using' to F# 'open'</target>
+        <note />
+      </trans-unit>
       <trans-unit id="ConvertToAnonymousRecord">
         <source>Convert to Anonymous Record</source>
         <target state="translated">In anonymen Datensatz konvertieren</target>

vsintegration/src/FSharp.Editor/xlf/FSharp.Editor.es.xlf

@@ -27,6 +27,11 @@
         <target state="translated">Agregar una anotación de tipo</target>
         <note />
       </trans-unit>
+      <trans-unit id="ConvertCSharpUsingToFSharpOpen">
+        <source>Convert C# 'using' to F# 'open'</source>
+        <target state="new">Convert C# 'using' to F# 'open'</target>
+        <note />
+      </trans-unit>
       <trans-unit id="ConvertToAnonymousRecord">
         <source>Convert to Anonymous Record</source>
         <target state="translated">Convertir en registro anónimo</target>

vsintegration/src/FSharp.Editor/xlf/FSharp.Editor.fr.xlf

@@ -27,6 +27,11 @@
         <target state="translated">Ajouter une annotation de type</target>
         <note />
       </trans-unit>
+      <trans-unit id="ConvertCSharpUsingToFSharpOpen">
+        <source>Convert C# 'using' to F# 'open'</source>
+        <target state="new">Convert C# 'using' to F# 'open'</target>
+        <note />
+      </trans-unit>
       <trans-unit id="ConvertToAnonymousRecord">
         <source>Convert to Anonymous Record</source>
         <target state="translated">Convertir en enregistrement anonyme</target>

vsintegration/src/FSharp.Editor/xlf/FSharp.Editor.it.xlf

@@ -27,6 +27,11 @@
         <target state="translated">Aggiungere l'annotazione di tipo</target>
         <note />
       </trans-unit>
+      <trans-unit id="ConvertCSharpUsingToFSharpOpen">
+        <source>Convert C# 'using' to F# 'open'</source>
+        <target state="new">Convert C# 'using' to F# 'open'</target>
+        <note />
+      </trans-unit>
       <trans-unit id="ConvertToAnonymousRecord">
         <source>Convert to Anonymous Record</source>
         <target state="translated">Converti in record anonimo</target>

vsintegration/src/FSharp.Editor/xlf/FSharp.Editor.ja.xlf

@@ -27,6 +27,11 @@
         <target state="translated">型の注釈の追加</target>
         <note />
       </trans-unit>
+      <trans-unit id="ConvertCSharpUsingToFSharpOpen">
+        <source>Convert C# 'using' to F# 'open'</source>
+        <target state="new">Convert C# 'using' to F# 'open'</target>
+        <note />
+      </trans-unit>
       <trans-unit id="ConvertToAnonymousRecord">
         <source>Convert to Anonymous Record</source>
         <target state="translated">匿名レコードに変換</target>

vsintegration/src/FSharp.Editor/xlf/FSharp.Editor.ko.xlf

@@ -27,6 +27,11 @@
         <target state="translated">형식 주석 추가</target>
         <note />
       </trans-unit>
+      <trans-unit id="ConvertCSharpUsingToFSharpOpen">
+        <source>Convert C# 'using' to F# 'open'</source>
+        <target state="new">Convert C# 'using' to F# 'open'</target>
+        <note />
+      </trans-unit>
       <trans-unit id="ConvertToAnonymousRecord">
         <source>Convert to Anonymous Record</source>
         <target state="translated">익명 레코드로 변환</target>

vsintegration/src/FSharp.Editor/xlf/FSharp.Editor.pl.xlf

@@ -27,6 +27,11 @@
         <target state="translated">Dodaj adnotację typu</target>
         <note />
       </trans-unit>
+      <trans-unit id="ConvertCSharpUsingToFSharpOpen">
+        <source>Convert C# 'using' to F# 'open'</source>
+        <target state="new">Convert C# 'using' to F# 'open'</target>
+        <note />
+      </trans-unit>
       <trans-unit id="ConvertToAnonymousRecord">
         <source>Convert to Anonymous Record</source>
         <target state="translated">Konwertuj na rekord anonimowy</target>

vsintegration/src/FSharp.Editor/xlf/FSharp.Editor.pt-BR.xlf

@@ -27,6 +27,11 @@
         <target state="translated">Adicionar uma anotação de tipo</target>
         <note />
       </trans-unit>
+      <trans-unit id="ConvertCSharpUsingToFSharpOpen">
+        <source>Convert C# 'using' to F# 'open'</source>
+        <target state="new">Convert C# 'using' to F# 'open'</target>
+        <note />
+      </trans-unit>
       <trans-unit id="ConvertToAnonymousRecord">
         <source>Convert to Anonymous Record</source>
         <target state="translated">Converter em Registro Anônimo</target>

vsintegration/src/FSharp.Editor/xlf/FSharp.Editor.ru.xlf

@@ -27,6 +27,11 @@
         <target state="translated">Добавить заметку типа</target>
         <note />
       </trans-unit>
+      <trans-unit id="ConvertCSharpUsingToFSharpOpen">
+        <source>Convert C# 'using' to F# 'open'</source>
+        <target state="new">Convert C# 'using' to F# 'open'</target>
+        <note />
+      </trans-unit>
       <trans-unit id="ConvertToAnonymousRecord">
         <source>Convert to Anonymous Record</source>
         <target state="translated">Преобразовать в анонимную запись</target>

vsintegration/src/FSharp.Editor/xlf/FSharp.Editor.tr.xlf

@@ -27,6 +27,11 @@
         <target state="translated">Tür ek açıklaması ekle</target>
         <note />
       </trans-unit>
+      <trans-unit id="ConvertCSharpUsingToFSharpOpen">
+        <source>Convert C# 'using' to F# 'open'</source>
+        <target state="new">Convert C# 'using' to F# 'open'</target>
+        <note />
+      </trans-unit>
       <trans-unit id="ConvertToAnonymousRecord">
         <source>Convert to Anonymous Record</source>
         <target state="translated">Anonim Kayda Dönüştür</target>

vsintegration/src/FSharp.Editor/xlf/FSharp.Editor.zh-Hans.xlf

@@ -27,6 +27,11 @@
         <target state="translated">添加类型注释</target>
         <note />
       </trans-unit>
+      <trans-unit id="ConvertCSharpUsingToFSharpOpen">
+        <source>Convert C# 'using' to F# 'open'</source>
+        <target state="new">Convert C# 'using' to F# 'open'</target>
+        <note />
+      </trans-unit>
       <trans-unit id="ConvertToAnonymousRecord">
         <source>Convert to Anonymous Record</source>
         <target state="translated">转换为匿名记录</target>

vsintegration/src/FSharp.Editor/xlf/FSharp.Editor.zh-Hant.xlf

@@ -27,6 +27,11 @@
         <target state="translated">新增型別註解</target>
         <note />
       </trans-unit>
+      <trans-unit id="ConvertCSharpUsingToFSharpOpen">
+        <source>Convert C# 'using' to F# 'open'</source>
+        <target state="new">Convert C# 'using' to F# 'open'</target>
+        <note />
+      </trans-unit>
       <trans-unit id="ConvertToAnonymousRecord">
         <source>Convert to Anonymous Record</source>
         <target state="translated">轉換為匿名記錄</target>