FileConventions: fix WrapText function

Split paragraph based on codeblock positions so that codeblocks
with two lines, are not broken into multiple paragraphs.

Fixes nblockchain#117

src/FileConventions/Library.fs

@@ -5,6 +5,8 @@ open System.IO
 open System.Linq
 open System.Text.RegularExpressions
 
+let codeBlockRegex = "\s*(```[\s\S]*```)\s*"
+
 let HasCorrectShebang(fileInfo: FileInfo) =
     let fileText = File.ReadLines fileInfo.FullName
 
@@ -148,8 +150,6 @@ type Text =
     }
 
 let SplitIntoWords(text: string) =
-    let codeBlockRegex = "\s*(```[\s\S]*```)\s*"
-
     let words =
         Regex.Split(text, codeBlockRegex)
         |> Seq.filter(fun item -> not(String.IsNullOrEmpty item))
@@ -241,9 +241,27 @@ let private WrapParagraph (text: string) (maxCharsPerLine: int) : string =
 
     processWords String.Empty String.Empty words
 
+let rec ExtractParagraphs (text: string) : List<string> =
+    let codeBlockParagraphRegex = "(?!\n\n)\s*(```[\s\S]*```)\s*"
+    let matchedRegex = Regex.Match(text, codeBlockParagraphRegex)
+
+    if matchedRegex.Success then
+        let beforeMatch = text.Substring(0, matchedRegex.Index)
+        let afterMatch = text.Substring(matchedRegex.Index + matchedRegex.Length)
+
+        let paragraphsBeforeMatch = ExtractParagraphs beforeMatch
+        let paragraphsAfterMatch = ExtractParagraphs afterMatch
+        paragraphsBeforeMatch @ (List.singleton matchedRegex.Value) @ paragraphsAfterMatch
+    elif String.IsNullOrEmpty(text) then
+        List.Empty
+    else
+        text.Split $"{Environment.NewLine}{Environment.NewLine}"
+        |> Seq.toList
+
 let WrapText (text: string) (maxCharsPerLine: int) : string =
+    Console.WriteLine (sprintf "%A" (ExtractParagraphs text))
     let wrappedParagraphs =
-        text.Split $"{Environment.NewLine}{Environment.NewLine}"
+        ExtractParagraphs text
         |> Seq.map(fun paragraph -> WrapParagraph paragraph maxCharsPerLine)
 
     String.Join(