Added a sample with nested sub commands

Author: JordanMarr

src/TestConsole/ProgramNestedSubCommands.fs

@@ -0,0 +1,57 @@
+module ProgramNestedSubCommands
+
+open System.IO
+open FSharp.SystemCommandLine
+
+let listCmd =
+    let handler (dir: DirectoryInfo) =
+        if dir.Exists then
+            dir.EnumerateFiles()
+            |> Seq.iter (fun f -> printfn "%s" f.FullName)
+        else
+            printfn $"{dir.FullName} does not exist."
+
+    let dir = Input.Argument("directory", DirectoryInfo(@"c:\default"))
+
+    command "list" {
+        description "lists contents of a directory"
+        inputs dir
+        setHandler handler
+        addAlias "ls"
+    }
+
+let deleteCmd =
+    let handler (dir: DirectoryInfo, recursive: bool) =
+        if dir.Exists then
+            if recursive then
+                printfn $"Recursively deleting {dir.FullName}"
+            else
+                printfn $"Deleting {dir.FullName}"
+        else
+            printfn $"{dir.FullName} does not exist."
+
+    let dir = Input.Argument("directory", DirectoryInfo(@"c:\default"))
+    let recursive = Input.Option("--recursive", false)
+
+    command "delete" {
+        description "deletes a directory"
+        inputs (dir, recursive)
+        setHandler handler
+        addAlias "del"
+    }
+
+let ioCmd = 
+    command "io" {
+        description "Contains IO related subcommands."
+        setHandler id
+        addCommands [ deleteCmd; listCmd ]
+    }
+
+
+// [<EntryPoint>]
+let main argv =
+    rootCommand argv {
+        description "Sample app for System.CommandLine"
+        setHandler id
+        addCommand ioCmd
+    }

src/TestConsole/Properties/launchSettings.json

@@ -1,16 +1,20 @@
 {
-    "profiles": {
-        "TestConsole": {
-            "commandName": "Project",
-            "commandLineArgs": "-w hello -w world"
-        },
-        "GT8": {
-            "commandName": "Project",
-            "commandLineArgs": "-a A -b B -c C -d D -e E -1 1 -2 2 -3 3 -4 4 -5 5"
-        },
-        "Leading @": {
-            "commandName": "Project",
-            "commandLineArgs": "--package @shoelace-style/shoelace"
-        }
-    }
+  "profiles": {
+    "TestConsole": {
+      "commandName": "Project",
+      "commandLineArgs": "-w hello -w world"
+    },
+    "GT8": {
+      "commandName": "Project",
+      "commandLineArgs": "-a A -b B -c C -d D -e E -1 1 -2 2 -3 3 -4 4 -5 5"
+    },
+    "Leading @": {
+      "commandName": "Project",
+      "commandLineArgs": "--package @shoelace-style/shoelace"
+    },
+    "IO Nested SubCommands": {
+      "commandName": "Project",
+      "commandLineArgs": "io list c:/data/"
+    },
+  }
 }

src/TestConsole/TestConsole.fsproj

@@ -9,6 +9,7 @@
     <Content Include="Properties\launchSettings.json" />
     <Compile Include="ProgramAlt1.fs" />
     <Compile Include="ProgramNoArgs.fs" />
+    <Compile Include="ProgramNestedSubCommands.fs" />
     <Compile Include="ProgramSubCommand.fs" />
     <Compile Include="ProgramTask.fs" />
     <Compile Include="ProgramTokenReplacer.fs" />