Fixed ArgumentMaybe; + tests

Author: JordanMarr

src/FSharp.SystemCommandLine/Inputs.fs

@@ -87,10 +87,11 @@ type Input =
         Option<'T option>(
             name,
             parseArgument = (fun argResult -> 
-                match argResult.Tokens |> Seq.tryHead with
-                | Some token -> Parser.parseTokenValue token.Value
-                | None -> failwith "F# Option can only be used with a single argument."
-            ),            
+                match argResult.Tokens |> Seq.toList with
+                | [] -> None
+                | [ token ] -> Parser.parseTokenValue token.Value
+                | _ :: _ -> failwith "F# Option can only be used with a single argument."
+            ), 
             description = (description |> Option.defaultValue null)
         ) 
         |> HandlerInput.OfOption
@@ -100,10 +101,11 @@ type Input =
         Option<'T option>(
             aliases |> Seq.toArray,
             parseArgument = (fun argResult -> 
-                match argResult.Tokens |> Seq.tryHead with
-                | Some token -> Parser.parseTokenValue token.Value
-                | None -> failwith "F# Option can only be used with a single argument."
-            ),            
+                match argResult.Tokens |> Seq.toList with
+                | [] -> None
+                | [ token ] -> Parser.parseTokenValue token.Value
+                | _ :: _ -> failwith "F# Option can only be used with a single argument."
+            ), 
             description = (description |> Option.defaultValue null)
         )
         |> HandlerInput.OfOption
@@ -130,11 +132,13 @@ type Input =
         Argument<'T option>(
             name,
             parse = (fun argResult -> 
-                match argResult.Tokens |> Seq.tryHead with
-                | Some token -> Parser.parseTokenValue token.Value
-                | None -> failwith "F# Option can only be used with a single argument."
-            ),   
-            description = (description |> Option.defaultValue null)
+                match argResult.Tokens |> Seq.toList with
+                | [] -> None
+                | [ token ] -> Parser.parseTokenValue token.Value
+                | _ :: _ -> failwith "F# Option can only be used with a single argument."
+            ), 
+            description = (description |> Option.defaultValue null),
+            isDefault = true
         ) 
         |> HandlerInput.OfArgument
 

src/Tests/ArgumentMaybeTest.fs

@@ -0,0 +1,38 @@
+module ArgumentMaybeTest
+
+open NUnit.Framework
+open Swensen.Unquote
+open FSharp.SystemCommandLine
+open Utils
+
+let nameMaybe = Input.ArgumentMaybe<string>("Maybe a name")
+
+let rootCmd argstr (handler: string option -> unit) = 
+    testRootCommand argstr {
+        description "Maybe displays a name"
+        inputs (nameMaybe)
+        setHandler handler
+    } 
+    |> ignore
+
+[<Test>]
+let ``01 Some jdoe`` () =    
+    let mutable handlerCalled = false
+    rootCmd "jdoe"
+        (fun (nameMaybe) ->
+            handlerCalled <- true
+            nameMaybe =! Some "jdoe"
+        )
+
+    handlerCalled =! true
+    
+[<Test>]
+let ``02 None`` () =    
+    let mutable handlerCalled = false
+    rootCmd ""
+        (fun (nameMaybe) ->
+            handlerCalled <- true
+            nameMaybe =! None
+        )
+
+    handlerCalled =! true

src/Tests/SimpleAsyncTest.fs

@@ -6,9 +6,9 @@ open FSharp.SystemCommandLine
 open Utils
 
 let words = Input.Option(["--word"; "-w"], Array.empty, "A list of words to be appended")
-let separator = Input.Option(["--separator"; "-s"], ",", "A character that will separate the joined words.")
+let separator = Input.OptionMaybe(["--separator"; "-s"], "A character that will separate the joined words.")
 
-let rootCmd argstr (handler: string array * string -> unit) = 
+let rootCmd argstr (handler: string array * string option -> unit) = 
     task {
         testRootCommand argstr {
             description "Appends words together"
@@ -23,6 +23,14 @@ let ``01 --word Hello -w World -s *`` () =
     rootCmd "--word Hello -w World -s *"
         (fun (words, separator) ->
             words =! [| "Hello"; "World" |]
-            separator =! "*"
+            separator =! Some "*"
+        )
+
+[<Test>]
+let ``02 --word Hello -w World`` () =
+    rootCmd "--word Hello -w World"
+        (fun (words, separator) ->
+            words =! [| "Hello"; "World" |]
+            separator =! None
         )
 

src/Tests/Tests.fsproj

@@ -10,6 +10,7 @@
   <ItemGroup>
     <Compile Include="Utils.fs" />
     <Compile Include="SubCommandAppTest.fs" />
+    <Compile Include="ArgumentMaybeTest.fs" />
     <Compile Include="SimpleAsyncTest.fs" />
     <Compile Include="SimpleAppTest.fs" />
     <Compile Include="Program.fs" />