Generate signature file

ReSharper.FSharp/src/FSharp.Psi.Intentions/FSharp.Psi.Intentions.fsproj

@@ -25,6 +25,7 @@
     <Compile Include="src\Intentions\SetNameAction.fs" />
     <Compile Include="src\Intentions\LetToUseAction.fs" />
     <Compile Include="src\Intentions\RenameFileToMatchTypeNameAction.fs" />
+    <Compile Include="src\Intentions\GenerateSignatureFileAction.fs" />
     <Compile Include="src\QuickFixes\FSharpQuickFixBase.fs" />
     <Compile Include="src\QuickFixes\RemoveUnusedOpensFix.fs" />
     <Compile Include="src\QuickFixes\ReplaceUseWithLetFix.fs" />

ReSharper.FSharp/src/FSharp.Psi.Intentions/src/Intentions/GenerateSignatureFileAction.fs

@@ -0,0 +1,53 @@
+namespace JetBrains.ReSharper.Plugins.FSharp.Psi.Features.ContextActions
+
+open System.IO
+open JetBrains.ProjectModel.ProjectsHost
+open JetBrains.RdBackend.Common.Features.ProjectModel
+open JetBrains.RdBackend.Common.Features.ProjectModel.View.Ordering
+open JetBrains.ReSharper.Feature.Services.ContextActions
+open JetBrains.ReSharper.Plugins.FSharp.Psi.Features.Intentions
+open type JetBrains.ReSharper.Psi.PsiSourceFileExtensions
+
+[<ContextAction(Group = "F#", Name = "Generate signature file for current file", Priority = 1s,
+                Description = "Generate signature file for current file.")>]
+type GenerateSignatureFileAction(dataProvider: FSharpContextActionDataProvider) =
+    inherit FSharpContextActionBase(dataProvider)
+
+    override this.Text = "Generate signature file for current file"
+
+    override this.IsAvailable _ =
+        let currentFSharpFile = dataProvider.PsiFile
+        let fcsService = currentFSharpFile.FcsCheckerService
+        let hasSignature = fcsService.FcsProjectProvider.HasPairFile dataProvider.SourceFile
+        not hasSignature
+
+    override this.ExecutePsiTransaction(solution, _) =
+        let projectFile = dataProvider.SourceFile.ToProjectFile()
+        let physicalPath = dataProvider.SourceFile.ToProjectFile().Location.FileAccessPath
+        let fsiFile = Path.ChangeExtension(physicalPath, ".fsi")
+
+        try
+            let currentFSharpFile = dataProvider.PsiFile
+            let fcsService = currentFSharpFile.FcsCheckerService
+            let checkResult = fcsService.ParseAndCheckFile(currentFSharpFile.GetSourceFile(), "for signature file", true)
+            do
+                match checkResult with
+                | None -> ()
+                | Some { CheckResults = checkResult } ->
+
+                match checkResult.GenerateSignature() with
+                | None -> ()
+                | Some signatureSourceText ->
+                    let content = string signatureSourceText
+                    File.WriteAllText(fsiFile, content)
+        with ex ->
+            // TODO: show some balloon thing?
+            ()
+
+        solution.InvokeUnderTransaction(fun transactionCookie ->
+            let virtualPath = FileSystemPath.TryParse(fsiFile).ToVirtualFileSystemPath()
+            let relativeTo = RelativeTo(projectFile, RelativeToType.Before)
+            transactionCookie.AddFile(projectFile.ParentFolder, virtualPath, context = OrderingContext(relativeTo))
+            |> ignore)
+
+        null