Carefuly handle cases when the .paket folder is present in .sln file, not present, or is empty.

integrationtests/Paket.IntegrationTests/ConvertFromNuGetSpecs.fs

@@ -90,15 +90,30 @@ let ``#1922 should remove references to moved analyzers``() =
     StringAssert.Contains(@"<Analyzer Include=""..\packages\StyleCop.Analyzers\analyzers\dotnet\cs\StyleCop.Analyzers.CodeFixes.dll"">", projectXml)
     StringAssert.Contains(@"<Analyzer Include=""..\packages\StyleCop.Analyzers\analyzers\dotnet\cs\StyleCop.Analyzers.dll"">", projectXml)
 
-[<Test>]
-let ``#2161 should put paket.dependencies inside the .paket folder when it's already present in the sln file``() =
-    let scenario = "i002161-convert-existing-paket-folder"
+let testPaketDependenciesFileInSolution scenario expectedFiles =
     paket "convert-from-nuget" scenario |> ignore
+
+    let expectedLines = 
+        [ yield "Project\\(\"{2150E333-8FDC-42A3-9474-1A3956D46DE8}\"\\) = \"\\.paket\", \"\\.paket\", \"{[^}]+}\""
+          yield "\s*ProjectSection\\(SolutionItems\\) = preProject"
+          for f in expectedFiles do yield sprintf "\s*%s = %s" f f
+          yield "\s*EndProjectSection"
+          yield "EndProject" ]
+        |> String.concat Environment.NewLine
+
+    let slnFileText = File.ReadAllText(Path.Combine(scenarioTempPath scenario, "sln.sln"))
 
-    let slnLines = File.ReadAllLines(Path.Combine(scenarioTempPath scenario, "2161.sln"))
-    let sectionOpenLine = slnLines |> Array.findIndex (fun line -> line.StartsWith "Project" && line.Contains "\".paket\"")
-    let sectionEndLine = sectionOpenLine + (slnLines |> Seq.skip sectionOpenLine |> Seq.findIndex (fun line -> line.StartsWith "EndProject"))
-    let depsFileLine = slnLines |> Array.findIndex (fun line -> line.Contains "paket.dependencies")
+    System.Text.RegularExpressions.Regex.IsMatch(slnFileText, expectedLines)
+    |> shouldEqual true
+
+[<Test>]
+let ``#2161 should put paket.dependencies inside the .paket folder when it's already present in the sln file``() =
+    testPaketDependenciesFileInSolution "i002161-convert-existing-paket-folder" ["paket.dependencies"]
 
-    sectionOpenLine |> shouldBeSmallerThan depsFileLine
-    sectionEndLine |> shouldBeGreaterThan depsFileLine
+[<Test>]
+let ``#2512 should put paket.dependencies inside the .paket folder when it's absent in the sln file``() =
+    testPaketDependenciesFileInSolution "i002512-convert-absent-paket-folder" ["paket.dependencies"]
+
+[<Test>]
+let ``#2512 should put paket.dependencies inside the .paket folder that already has files in it``() =
+    testPaketDependenciesFileInSolution "i002512-convert-paket-folder-with-files" ["paket.dependencies"; "SomeFile"]

integrationtests/scenarios/i002512-convert-absent-paket-folder/before/proj.fsproj

@@ -0,0 +1,10 @@
+<Project Sdk="FSharp.NET.Sdk;Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>netcoreapp1.1</TargetFramework>
+  </PropertyGroup>
+  <ItemGroup>
+    <Compile Include="Program.fs" />
+  </ItemGroup>
+  <Import Project="..\.paket\Paket.Restore.targets" />
+</Project>

integrationtests/scenarios/i002512-convert-absent-paket-folder/before/sln.sln

@@ -0,0 +1,34 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio 15
+VisualStudioVersion = 15.0.26124.0
+MinimumVisualStudioVersion = 15.0.26124.0
+Project("{6EC3EE1D-3C4E-46DD-8F32-0CC8E7565705}") = "proj", "proj.fsproj", "{5AB9014A-86E7-4A3C-8731-AC5220ABB7F8}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Debug|x64 = Debug|x64
+		Debug|x86 = Debug|x86
+		Release|Any CPU = Release|Any CPU
+		Release|x64 = Release|x64
+		Release|x86 = Release|x86
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{5AB9014A-86E7-4A3C-8731-AC5220ABB7F8}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{5AB9014A-86E7-4A3C-8731-AC5220ABB7F8}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{5AB9014A-86E7-4A3C-8731-AC5220ABB7F8}.Debug|x64.ActiveCfg = Debug|x64
+		{5AB9014A-86E7-4A3C-8731-AC5220ABB7F8}.Debug|x64.Build.0 = Debug|x64
+		{5AB9014A-86E7-4A3C-8731-AC5220ABB7F8}.Debug|x86.ActiveCfg = Debug|x86
+		{5AB9014A-86E7-4A3C-8731-AC5220ABB7F8}.Debug|x86.Build.0 = Debug|x86
+		{5AB9014A-86E7-4A3C-8731-AC5220ABB7F8}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{5AB9014A-86E7-4A3C-8731-AC5220ABB7F8}.Release|Any CPU.Build.0 = Release|Any CPU
+		{5AB9014A-86E7-4A3C-8731-AC5220ABB7F8}.Release|x64.ActiveCfg = Release|x64
+		{5AB9014A-86E7-4A3C-8731-AC5220ABB7F8}.Release|x64.Build.0 = Release|x64
+		{5AB9014A-86E7-4A3C-8731-AC5220ABB7F8}.Release|x86.ActiveCfg = Release|x86
+		{5AB9014A-86E7-4A3C-8731-AC5220ABB7F8}.Release|x86.Build.0 = Release|x86
+	EndGlobalSection
+EndGlobal

integrationtests/scenarios/i002512-convert-paket-folder-with-files/before/proj.fsproj

@@ -0,0 +1,10 @@
+<Project Sdk="FSharp.NET.Sdk;Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>netcoreapp1.1</TargetFramework>
+  </PropertyGroup>
+  <ItemGroup>
+    <Compile Include="Program.fs" />
+  </ItemGroup>
+  <Import Project="..\.paket\Paket.Restore.targets" />
+</Project>

integrationtests/scenarios/i002512-convert-paket-folder-with-files/before/sln.sln

@@ -0,0 +1,39 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio 15
+VisualStudioVersion = 15.0.26124.0
+MinimumVisualStudioVersion = 15.0.26124.0
+Project("{6EC3EE1D-3C4E-46DD-8F32-0CC8E7565705}") = "proj", "proj.fsproj", "{5AB9014A-86E7-4A3C-8731-AC5220ABB7F8}"
+EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = ".paket", ".paket", "{75DC0F05-EDD7-4CAD-B88E-9BA4DFCDDAE2}"
+	ProjectSection(SolutionItems) = preProject
+		SomeFile = SomeFile
+	EndProjectSection
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Debug|x64 = Debug|x64
+		Debug|x86 = Debug|x86
+		Release|Any CPU = Release|Any CPU
+		Release|x64 = Release|x64
+		Release|x86 = Release|x86
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{5AB9014A-86E7-4A3C-8731-AC5220ABB7F8}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{5AB9014A-86E7-4A3C-8731-AC5220ABB7F8}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{5AB9014A-86E7-4A3C-8731-AC5220ABB7F8}.Debug|x64.ActiveCfg = Debug|x64
+		{5AB9014A-86E7-4A3C-8731-AC5220ABB7F8}.Debug|x64.Build.0 = Debug|x64
+		{5AB9014A-86E7-4A3C-8731-AC5220ABB7F8}.Debug|x86.ActiveCfg = Debug|x86
+		{5AB9014A-86E7-4A3C-8731-AC5220ABB7F8}.Debug|x86.Build.0 = Debug|x86
+		{5AB9014A-86E7-4A3C-8731-AC5220ABB7F8}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{5AB9014A-86E7-4A3C-8731-AC5220ABB7F8}.Release|Any CPU.Build.0 = Release|Any CPU
+		{5AB9014A-86E7-4A3C-8731-AC5220ABB7F8}.Release|x64.ActiveCfg = Release|x64
+		{5AB9014A-86E7-4A3C-8731-AC5220ABB7F8}.Release|x64.Build.0 = Release|x64
+		{5AB9014A-86E7-4A3C-8731-AC5220ABB7F8}.Release|x86.ActiveCfg = Release|x86
+		{5AB9014A-86E7-4A3C-8731-AC5220ABB7F8}.Release|x86.Build.0 = Release|x86
+	EndGlobalSection
+EndGlobal

src/Paket.Core/PaketConfigFiles/SolutionFile.fs

@@ -22,12 +22,15 @@ type SolutionFile(fileName: string) =
                 content.RemoveRange(index, 4)
         | None -> ()
 
+    let projectSectionLines = 
+        [ "\tProjectSection(SolutionItems) = preProject";
+          "\tEndProjectSection" ]
+
     let addPaketFolder () = 
         let lines = 
-            [sprintf   "Project(\"{%s}\") = \".paket\", \".paket\", \"{%s}\"" Constants.SolutionFolderProjectGuid (Guid.NewGuid().ToString("D").ToUpper());
-                       "	ProjectSection(SolutionItems) = preProject";
-                       "	EndProjectSection";
-                       "EndProject"]
+              [sprintf "Project(\"{%s}\") = \".paket\", \".paket\", \"{%s}\"" Constants.SolutionFolderProjectGuid (Guid.NewGuid().ToString("D").ToUpper())]
+            @ projectSectionLines
+            @ [ "EndProject" ]
 
         let index = 
             match content |> Seq.tryFindIndex (fun line -> line.StartsWith("Project")) with
@@ -46,10 +49,24 @@ type SolutionFile(fileName: string) =
 
     let addPaketFiles(paketProjectIndex, length, dependenciesFile, lockFile) = 
         let projectLines = content.GetRange(paketProjectIndex, length)
+
+        // This here is ad-hoc hacky solution to sln ambiguity.
+        // The problen is that the .sln file may or may not contain a "ProjectSection" within the ".paket" "Project" (see #2161 and #2512).
+        // When the "ProjectSection" is not there, we need to add it, and then add new files within it.
+        // A better solution would be to have a proper parser for the .sln file, but that would take too long, and would probably be a waste anyway.
+        let firstLineInPaketProject = if paketProjectIndex < content.Count-1 then content.[paketProjectIndex+1] else ""
+        if not (firstLineInPaketProject.Contains "ProjectSection") then
+            if firstLineInPaketProject.Contains "EndProject" then 
+                // The "Project" is empty => insert "ProjectSection"
+                content.InsertRange( paketProjectIndex+1, projectSectionLines )
+            else 
+                // The "Project" is not empty, but also doesn't contain a "ProjectSection" => no idea what this means, 
+                // so just fall back to old behavior and insert new lines at +2 after "Project" start.
+                ()
 
         let add s =
             if not <| Seq.exists (fun line -> line = s) projectLines 
-            then content.Insert(paketProjectIndex + 1, s)
+            then content.Insert(paketProjectIndex + 2, s)
 
         Option.iter (fun lockFile -> 
             add (sprintf"		%s = %s" lockFile lockFile)) lockFile