Improve code based on analyzers.

Author: nojaf

src/Common/Collections.fs

@@ -103,7 +103,7 @@ module internal List =
 
 /// Represents a tree with nodes containing values an a list of children
 ///
-type internal Tree<'T> = Node of 'T * list<Tree<'T>>
+type internal Tree<'T> = Node of self: 'T * children: Tree<'T> list
 
 module internal Tree =
     /// Takes all elements at the specified level and turns them into nodes

src/Common/StringParsing.fs

@@ -299,7 +299,7 @@ module StringPosition =
     /// complete repetitions of a specified sub-string.
     let (|EqualsRepeated|_|) (repeated, _n: MarkdownRange) =
         function
-        | StartsWithRepeated repeated (_n, ("", _)) -> Some()
+        | StartsWithRepeated repeated (_n, (v, _)) when not (String.IsNullOrWhiteSpace v) -> Some()
         | _ -> None
 
 module List =

src/FSharp.Formatting.ApiDocs/GenerateModel.fs

@@ -690,22 +690,23 @@ type ApiDocEntityInfo
 [<AutoOpen>]
 module internal CrossReferences =
     let getXmlDocSigForType (typ: FSharpEntity) =
-        match typ.XmlDocSig with
-        | "" ->
+        if not (String.IsNullOrWhiteSpace typ.XmlDocSig) then
+            typ.XmlDocSig
+        else
             try
                 defaultArg (Option.map (sprintf "T:%s") typ.TryFullName) ""
             with _ ->
                 ""
-        | n -> n
 
     let getMemberXmlDocsSigPrefix (memb: FSharpMemberOrFunctionOrValue) =
         if memb.IsEvent then "E"
         elif memb.IsProperty then "P"
         else "M"
 
     let getXmlDocSigForMember (memb: FSharpMemberOrFunctionOrValue) =
-        match memb.XmlDocSig with
-        | "" ->
+        if not (String.IsNullOrWhiteSpace memb.XmlDocSig) then
+            memb.XmlDocSig
+        else
             let memberName =
                 try
                     let name = memb.CompiledName.Replace(".ctor", "#ctor")
@@ -757,7 +758,6 @@ module internal CrossReferences =
             match (memb.DeclaringEntity.Value.TryFullName) with
             | None -> ""
             | Some(n) -> sprintf "%s:%s.%s" (getMemberXmlDocsSigPrefix memb) n memberName
-        | n -> n
 
 type internal CrefReference =
     { IsInternal: bool

src/fsdocs-tool/BuildCommand.fs

@@ -52,7 +52,10 @@ type internal DocContent
         let mutable counter = 0
 
         fun (url: string) ->
-            if url.StartsWith("http") || url.StartsWith("https") then
+            if
+                url.StartsWith("http", StringComparison.Ordinal)
+                || url.StartsWith("https", StringComparison.Ordinal)
+            then
                 counter <- counter + 1
                 let ext = Path.GetExtension(url)
 
@@ -134,8 +137,8 @@ type internal DocContent
         [ let inputFileName = Path.GetFileName(inputFileFullPath)
 
           if
-              not (inputFileName.StartsWith("."))
-              && not (inputFileName.StartsWith "_template")
+              not (inputFileName.StartsWith('.'))
+              && not (inputFileName.StartsWith("_template", StringComparison.Ordinal))
           then
               let inputFileFullPath = Path.GetFullPath(inputFileFullPath)
 
@@ -157,7 +160,7 @@ type internal DocContent
 
           for subInputFolderFullPath in Directory.EnumerateDirectories(inputFolderAsGiven) do
               let subInputFolderName = Path.GetFileName(subInputFolderFullPath)
-              let subFolderIsSkipped = subInputFolderName.StartsWith "."
+              let subFolderIsSkipped = subInputFolderName.StartsWith '.'
               let subFolderIsOutput = subFolderIsOutput subInputFolderFullPath
 
               if not subFolderIsOutput && not subFolderIsSkipped then
@@ -179,9 +182,9 @@ type internal DocContent
         =
         [ let name = Path.GetFileName(inputFileFullPath)
 
-          if name.StartsWith(".") then
+          if name.StartsWith('.') then
               printfn "skipping file %s" inputFileFullPath
-          elif not (name.StartsWith "_template") then
+          elif not (name.StartsWith("_template", StringComparison.Ordinal)) then
               let isFsx = inputFileFullPath.EndsWith(".fsx", true, CultureInfo.InvariantCulture)
 
               let isMd = inputFileFullPath.EndsWith(".md", true, CultureInfo.InvariantCulture)
@@ -510,7 +513,7 @@ type internal DocContent
 
           for subInputFolderFullPath in Directory.EnumerateDirectories(inputFolderAsGiven) do
               let subInputFolderName = Path.GetFileName(subInputFolderFullPath)
-              let subFolderIsSkipped = subInputFolderName.StartsWith "."
+              let subFolderIsSkipped = subInputFolderName.StartsWith '.'
               let subFolderIsOutput = subFolderIsOutput subInputFolderFullPath
 
               if subFolderIsOutput || subFolderIsSkipped then
@@ -1457,7 +1460,7 @@ type CoreBuildOptions(watch) =
         let apiDocOtherFlags =
             [ for (_dllFile, otherFlags, _, _, _, _, _, _, _, _) in crackedProjects do
                   for otherFlag in otherFlags do
-                      if otherFlag.StartsWith("-r:") then
+                      if otherFlag.StartsWith("-r:", StringComparison.Ordinal) then
                           if File.Exists(otherFlag.[3..]) then
                               yield otherFlag
                           else
@@ -1637,7 +1640,7 @@ type CoreBuildOptions(watch) =
 
                     // Used to resolve code references in content with respect to the API Docs model
                     let resolveInlineCodeReference (s: string) =
-                        if s.StartsWith("cref:") then
+                        if s.StartsWith("cref:", StringComparison.Ordinal) then
                             let s = s.[5..]
 
                             match model.Resolver.ResolveCref s with
@@ -1775,7 +1778,7 @@ type CoreBuildOptions(watch) =
                     File.Delete file |> ignore
 
                 for subdir in Directory.EnumerateDirectories dir do
-                    if not (Path.GetFileName(subdir).StartsWith ".") then
+                    if not (Path.GetFileName(subdir).StartsWith '.') then
                         clean subdir
 
             let isOutputPathOK =

src/fsdocs-tool/Options.fs

@@ -2,12 +2,8 @@ namespace fsdocs
 
 module Common =
 
-    let evalString s = if s = "" then None else Some s
-
-    let evalStrings a =
-        match Seq.tryExactlyOne a with
-        | Some "" -> None
-        | _ -> Some(List.ofSeq a)
+    let evalString s =
+        if System.String.IsNullOrEmpty s then None else Some s
 
     // https://stackoverflow.com/questions/4126351
     let private pairs (xs: _ seq) =
@@ -22,12 +18,12 @@ module Common =
                     yield first, second
         }
 
-    let evalPairwiseStrings a =
-        match Seq.tryExactlyOne a with
+    let evalPairwiseStrings (a: string array) =
+        match Array.tryExactlyOne a with
         | Some "" -> None
         | _ -> a |> pairs |> List.ofSeq |> Some
 
-    let evalPairwiseStringsNoOption a =
+    let evalPairwiseStringsNoOption (a: string array) =
         evalPairwiseStrings a |> Option.defaultValue []
 
     let concat a =

src/fsdocs-tool/ProjectCracker.fs

@@ -138,7 +138,7 @@ module Utils =
             res
 
     let ensureTrailingSlash (s: string) =
-        if s.EndsWith("/") || s.EndsWith(".html") then
+        if s.EndsWith '/' || s.EndsWith(".html", StringComparison.Ordinal) then
             s
         else
             s + "/"
@@ -456,7 +456,7 @@ module Crack =
             |> List.filter (fun s ->
                 let isFSharpFormattingTestProject =
                     s.Contains $"FSharp.ApiDocs.Tests{Path.DirectorySeparatorChar}files"
-                    || s.EndsWith "FSharp.Formatting.TestHelpers.fsproj"
+                    || s.EndsWith("FSharp.Formatting.TestHelpers.fsproj", StringComparison.Ordinal)
 
                 if isFSharpFormattingTestProject then
                     printfn