From 1f5b27974493af3cb6d9ea217fb5720b4c931a79 Mon Sep 17 00:00:00 2001
From: Matthias Dittrich <matthi.d@gmail.com>
Date: Thu, 17 Dec 2015 18:34:08 +0100
Subject: [PATCH] Fixes a bug/crash when a fenced code block starts with an
 empty line

- Fixes the bug (only remove the line-ending character when
  FSharp.Formatting commands are found).
- Upgrades some missing projects to net45 (because the bugfix contains
  logging which is in FSharp.Formatting.Common, which in itself is build
  for net45)
---
 src/Common/StringParsing.fs                   | 20 ++++++
 .../FSharp.CodeFormat.fsproj                  |  7 ++
 src/FSharp.Literate/Transformations.fs        | 10 +--
 src/FSharp.Markdown/FSharp.Markdown.fsproj    | 11 +++-
 tests/FSharp.Literate.Tests/Tests.fs          | 41 ++++++++++++
 tests/FSharp.Markdown.Tests/App.config        | 66 +++++++++----------
 .../FSharp.Markdown.Tests.fsproj              |  2 +-
 7 files changed, 114 insertions(+), 43 deletions(-)

diff --git a/src/Common/StringParsing.fs b/src/Common/StringParsing.fs
index a4e8d67f7..baedfc451 100644
--- a/src/Common/StringParsing.fs
+++ b/src/Common/StringParsing.fs
@@ -78,6 +78,26 @@ module String =
     if n = 0 || n % repeated.Length <> 0 then None
     else Some(n/repeated.Length, text.Substring(n, text.Length - n)) 
 
+  /// Ignores everything until a end-line character is detected, returns the remaining string.
+  let (|SkipSingleLine|) (text:string) =
+    let rec tryEol eolList =
+      match eolList with
+      | h : string :: t ->
+        match text.IndexOf(h) with
+        | i when i < 0 -> tryEol t
+        | i ->
+          text.Substring (i + h.Length)
+      | _ ->
+        text
+    let result = tryEol [ "\r\n"; "\n" ]
+    let skipped = text.Substring(0, text.Length - result.Length)
+    if not <| String.IsNullOrWhiteSpace(skipped) then
+      FSharp.Formatting.Common.Log.warnf "skipped '%s' which contains non-whitespace character!" skipped
+    if result = text then
+      FSharp.Formatting.Common.Log.warnf "could not skip a line of %s, because no line-ending character was found!" text
+    result
+
+
   /// Matches when a string starts with a sub-string wrapped using the 
   /// opening and closing sub-string specified in the parameter.
   /// For example "[aa]bc" is wrapped in [ and ] pair. Returns the wrapped
diff --git a/src/FSharp.CodeFormat/FSharp.CodeFormat.fsproj b/src/FSharp.CodeFormat/FSharp.CodeFormat.fsproj
index 3f20618a5..6b89954cf 100644
--- a/src/FSharp.CodeFormat/FSharp.CodeFormat.fsproj
+++ b/src/FSharp.CodeFormat/FSharp.CodeFormat.fsproj
@@ -93,6 +93,13 @@
     <Reference Include="System.Numerics" />
     <Reference Include="System.Web" />
   </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\FSharp.Formatting.Common\FSharp.Formatting.Common.fsproj">
+      <Name>FSharp.Formatting.Common</Name>
+      <Project>{91bad90e-bf3b-4646-a1a7-1568f8f25075}</Project>
+      <Private>True</Private>
+    </ProjectReference>
+  </ItemGroup>
   <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
 	     Other similar extension points exist, see Microsoft.Common.targets.
 	<Target Name="BeforeBuild">
diff --git a/src/FSharp.Literate/Transformations.fs b/src/FSharp.Literate/Transformations.fs
index a514f9d20..141a42ca0 100644
--- a/src/FSharp.Literate/Transformations.fs
+++ b/src/FSharp.Literate/Transformations.fs
@@ -21,9 +21,9 @@ module Transformations =
   /// to colorize. We skip snippets that specify non-fsharp langauge e.g. [lang=csharp].
   let rec collectCodeSnippets par = seq {
     match par with
-    | CodeBlock((String.StartsWithWrapped ("[", "]") (ParseCommands cmds, String.TrimStart code)), language, _) 
+    | CodeBlock((String.StartsWithWrapped ("[", "]") (ParseCommands cmds, String.SkipSingleLine code)), language, _)
         when (not (String.IsNullOrWhiteSpace(language)) && language <> "fsharp") || (cmds.ContainsKey("lang") && cmds.["lang"] <> "fsharp") -> ()
-    | CodeBlock((String.StartsWithWrapped ("[", "]") (ParseCommands cmds, String.TrimStart code)), _, _) 
+    | CodeBlock((String.StartsWithWrapped ("[", "]") (ParseCommands cmds, String.SkipSingleLine code)), _, _)
     | CodeBlock(Let (dict []) (cmds, code), _, _) ->
         let modul = 
           match cmds.TryGetValue("module") with
@@ -39,12 +39,8 @@ module Transformations =
   /// Replace CodeBlock elements with formatted HTML that was processed by the F# snippets tool
   /// (The dictionary argument is a map from original code snippets to formatted HTML snippets.)
   let rec replaceCodeSnippets path (codeLookup:IDictionary<_, _>) = function
-    | CodeBlock ((String.StartsWithWrapped ("[", "]") (ParseCommands cmds, code)), language, _) 
+    | CodeBlock ((String.StartsWithWrapped ("[", "]") (ParseCommands cmds, String.SkipSingleLine code)), language, _)
     | CodeBlock(Let (dict []) (cmds, code), language, _) ->
-        let code = 
-            if code.StartsWith("\r\n") then code.Substring(2)
-            elif code.StartsWith("\n") then code.Substring(1)
-            else code
         if cmds.ContainsKey("hide") then None else
         let code = 
           if cmds.ContainsKey("file") && cmds.ContainsKey("key") then 
diff --git a/src/FSharp.Markdown/FSharp.Markdown.fsproj b/src/FSharp.Markdown/FSharp.Markdown.fsproj
index f855640e7..d6e121dc7 100644
--- a/src/FSharp.Markdown/FSharp.Markdown.fsproj
+++ b/src/FSharp.Markdown/FSharp.Markdown.fsproj
@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="utf-8"?>
+<?xml version="1.0" encoding="utf-8"?>
 <Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <PropertyGroup>
     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
@@ -10,7 +10,7 @@
     <RootNamespace>FSharp.Markdown</RootNamespace>
     <AssemblyName>
     </AssemblyName>
-    <TargetFrameworkVersion>v4.0</TargetFrameworkVersion>
+    <TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
     <TargetFrameworkProfile>
     </TargetFrameworkProfile>
     <Name>FSharp.Markdown</Name>
@@ -64,6 +64,13 @@
     <Compile Include="LatexFormatting.fs" />
     <Compile Include="Main.fs" />
   </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\FSharp.Formatting.Common\FSharp.Formatting.Common.fsproj">
+      <Name>FSharp.Formatting.Common</Name>
+      <Project>{91bad90e-bf3b-4646-a1a7-1568f8f25075}</Project>
+      <Private>True</Private>
+    </ProjectReference>
+  </ItemGroup>
   <PropertyGroup>
     <MinimumVisualStudioVersion Condition="'$(MinimumVisualStudioVersion)' == ''">11</MinimumVisualStudioVersion>
   </PropertyGroup>
diff --git a/tests/FSharp.Literate.Tests/Tests.fs b/tests/FSharp.Literate.Tests/Tests.fs
index 24c8167ac..b5499c7f5 100644
--- a/tests/FSharp.Literate.Tests/Tests.fs
+++ b/tests/FSharp.Literate.Tests/Tests.fs
@@ -122,6 +122,19 @@ let test = 42
   doc.Paragraphs |> shouldMatchPar (function
     | Paragraph [Strong [Literal "hello"]] -> true | _ -> false)
 
+[<Test>]
+let ``Can parse and format markdown with Github-flavoured F# snippet starting and ending with empty lines`` () =
+  let content = """
+```fsharp
+
+let test = 42
+
+```"""
+  let doc = Literate.ParseMarkdownString(content, formatAgent = getFormatAgent())
+  doc.Errors |> Seq.length |> shouldEqual 0
+  doc.Paragraphs |> shouldMatchPar (function
+    | Matching.LiterateParagraph(FormattedCode(_)) -> true | _ -> false)
+
 [<Test>]
 let ``Can generate references from indirect links`` () =
   let content = """
@@ -206,6 +219,34 @@ let ``Correctly handles Norwegian letters in SQL code block (#249)`` () =
   let html = Literate.WriteHtml(doc)
   html |> should contain ">Æøå<"
 
+[<Test>]
+let ``Correctly handles code starting with whitespace`` () =
+  let content = """
+    [lang=unknown]
+      inner"""
+  let doc = Literate.ParseMarkdownString(content, formatAgent=getFormatAgent())
+  let html = Literate.WriteHtml(doc)
+  html |> should contain ">  inner<"
+
+[<Test>]
+let ``Correctly handles code which garbage after commands`` () =
+  // This will trigger a warning!
+  let content = """
+    [lang=unknown] some ignored garbage
+      inner"""
+  let doc = Literate.ParseMarkdownString(content, formatAgent=getFormatAgent())
+  let html = Literate.WriteHtml(doc)
+  html |> should contain ">  inner<"
+
+[<Test>]
+let ``Correctly handles code after the commands`` () =
+  // This will work, but trigger a warning!
+  let content = """
+    [lang=unknown] let this be some code"""
+  let doc = Literate.ParseMarkdownString(content, formatAgent=getFormatAgent())
+  let html = Literate.WriteHtml(doc)
+  html |> should contain " let this be some code"
+
 [<Test>]
 let ``Correctly handles apostrophes in JS code block (#213)`` () =
   let content = """
diff --git a/tests/FSharp.Markdown.Tests/App.config b/tests/FSharp.Markdown.Tests/App.config
index 511e709ff..b2f956134 100644
--- a/tests/FSharp.Markdown.Tests/App.config
+++ b/tests/FSharp.Markdown.Tests/App.config
@@ -1,38 +1,38 @@
 <?xml version="1.0" encoding="utf-8"?>
 <configuration>
   <startup>
-    <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.0" />
+    <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5" />
   </startup>
   <runtime>
-    
-  <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
-    <dependentAssembly>
-      <assemblyIdentity name="Microsoft.Build.Engine" publicKeyToken="b03f5f7f11d50a3a" culture="neutral" />
-      <bindingRedirect oldVersion="4.0.0.0" newVersion="12.0.0.0" />
-    </dependentAssembly>
-    <dependentAssembly>
-      <assemblyIdentity name="Microsoft.Build.Framework" publicKeyToken="b03f5f7f11d50a3a" culture="neutral" />
-      <bindingRedirect oldVersion="4.0.0.0" newVersion="12.0.0.0" />
-    </dependentAssembly>
-  <dependentAssembly>
-    <assemblyIdentity name="FSharp.Core" publicKeyToken="b03f5f7f11d50a3a" culture="neutral" />
-    <bindingRedirect oldVersion="2.0.0.0-4.3.0.0" newVersion="4.3.1.0" />
-  </dependentAssembly>
-  <dependentAssembly>
-    <assemblyIdentity name="CommandLine" publicKeyToken="de6f01bd326f8c32" culture="neutral" />
-    <bindingRedirect oldVersion="0.0.0.0-1.9.71.2" newVersion="1.9.71.2" />
-  </dependentAssembly>
-  <dependentAssembly>
-    <assemblyIdentity name="System.Web.Razor" publicKeyToken="31bf3856ad364e35" culture="neutral" />
-    <bindingRedirect oldVersion="0.0.0.0-2.0.0.0" newVersion="2.0.0.0" />
-  </dependentAssembly>
-  <dependentAssembly>
-    <assemblyIdentity name="nunit.framework" publicKeyToken="96d09a1eb7f44a77" culture="neutral" />
-    <bindingRedirect oldVersion="0.0.0.0-2.6.4.14350" newVersion="2.6.4.14350" />
-  </dependentAssembly>
-  <dependentAssembly>
-    <assemblyIdentity name="RazorEngine" publicKeyToken="9ee697374c7e744a" culture="neutral" />
-    <bindingRedirect oldVersion="0.0.0.0-3.3.0.0" newVersion="3.3.0.0" />
-  </dependentAssembly>
-</assemblyBinding></runtime>
-</configuration>
+    <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
+      <dependentAssembly>
+        <assemblyIdentity name="Microsoft.Build.Engine" publicKeyToken="b03f5f7f11d50a3a" culture="neutral" />
+        <bindingRedirect oldVersion="4.0.0.0" newVersion="12.0.0.0" />
+      </dependentAssembly>
+      <dependentAssembly>
+        <assemblyIdentity name="Microsoft.Build.Framework" publicKeyToken="b03f5f7f11d50a3a" culture="neutral" />
+        <bindingRedirect oldVersion="4.0.0.0" newVersion="12.0.0.0" />
+      </dependentAssembly>
+      <dependentAssembly>
+        <assemblyIdentity name="FSharp.Core" publicKeyToken="b03f5f7f11d50a3a" culture="neutral" />
+        <bindingRedirect oldVersion="2.0.0.0-4.3.0.0" newVersion="4.3.1.0" />
+      </dependentAssembly>
+      <dependentAssembly>
+        <assemblyIdentity name="CommandLine" publicKeyToken="de6f01bd326f8c32" culture="neutral" />
+        <bindingRedirect oldVersion="0.0.0.0-1.9.71.2" newVersion="1.9.71.2" />
+      </dependentAssembly>
+      <dependentAssembly>
+        <assemblyIdentity name="System.Web.Razor" publicKeyToken="31bf3856ad364e35" culture="neutral" />
+        <bindingRedirect oldVersion="0.0.0.0-2.0.0.0" newVersion="2.0.0.0" />
+      </dependentAssembly>
+      <dependentAssembly>
+        <assemblyIdentity name="nunit.framework" publicKeyToken="96d09a1eb7f44a77" culture="neutral" />
+        <bindingRedirect oldVersion="0.0.0.0-2.6.4.14350" newVersion="2.6.4.14350" />
+      </dependentAssembly>
+      <dependentAssembly>
+        <assemblyIdentity name="RazorEngine" publicKeyToken="9ee697374c7e744a" culture="neutral" />
+        <bindingRedirect oldVersion="0.0.0.0-3.3.0.0" newVersion="3.3.0.0" />
+      </dependentAssembly>
+    </assemblyBinding>
+  </runtime>
+</configuration>
\ No newline at end of file
diff --git a/tests/FSharp.Markdown.Tests/FSharp.Markdown.Tests.fsproj b/tests/FSharp.Markdown.Tests/FSharp.Markdown.Tests.fsproj
index c2f53203d..e715db6aa 100644
--- a/tests/FSharp.Markdown.Tests/FSharp.Markdown.Tests.fsproj
+++ b/tests/FSharp.Markdown.Tests/FSharp.Markdown.Tests.fsproj
@@ -9,7 +9,7 @@
     <OutputType>Library</OutputType>
     <RootNamespace>FSharp.Markdown.Tests</RootNamespace>
     <AssemblyName>FSharp.Markdown.Tests</AssemblyName>
-    <TargetFrameworkVersion>v4.0</TargetFrameworkVersion>
+    <TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
     <TargetFrameworkProfile>
     </TargetFrameworkProfile>
     <Name>FSharp.Markdown.Tests</Name>