Allow specifying descriptive argument for flag in short and/or long.

spec/flag_spec.cr

@@ -0,0 +1,60 @@
+require "./spec_helper"
+
+describe Commander::Flag do
+
+  it "parses descriptive argument from short" do
+    flag = Commander::Flag.new do |flag|
+      flag.name = "suffix"
+      flag.description = flag.name
+      flag.short = "-s DIR"
+      flag.long = "--suffix"
+      flag.default = ""
+    end
+
+    flag.long.should eq("--suffix")
+    flag.short.should eq("-s")
+    flag.arg.should eq("DIR")
+  end
+
+  it "parses descriptive argument from long" do
+    flag = Commander::Flag.new do |flag|
+      flag.name = "suffix"
+      flag.description = flag.name
+      flag.short = "-s"
+      flag.long = "--suffix DIR"
+      flag.default = ""
+    end
+
+    flag.long.should eq("--suffix")
+    flag.short.should eq("-s")
+    flag.arg.should eq("DIR")
+  end
+
+  it "parses descriptive argument from short if both present" do
+    flag = Commander::Flag.new do |flag|
+      flag.name = "suffix"
+      flag.description = flag.name
+      flag.short = "-s DIR"
+      flag.long = "--suffix DIR"
+      flag.default = ""
+    end
+
+    flag.long.should eq("--suffix")
+    flag.short.should eq("-s")
+    flag.arg.should eq("DIR")
+  end
+
+  it "ignores descriptive argument if absent from both short and long" do
+    flag = Commander::Flag.new do |flag|
+      flag.name = "suffix"
+      flag.description = flag.name
+      flag.short = "-s"
+      flag.long = "--suffix"
+      flag.default = ""
+    end
+
+    flag.long.should eq("--suffix")
+    flag.short.should eq("-s")
+    flag.arg.should be_nil
+  end
+end

spec/help_spec.cr

@@ -7,11 +7,41 @@ describe Commander do
       cmd.long = "my program's (long) description."
 
       cmd.flags.add do |flag|
-        flag.name = "suffix"
-        flag.short = "-s"
+        flag.name = "suffix-short"
+        flag.short = "-s DIR"
+        flag.default = ""
+        flag.description = "Suffix specified using a short flag and descriptive argument."
+      end
+
+      cmd.flags.add do |flag|
+        flag.name = "suffix-long"
+        flag.long = "--suffix DIR"
+        flag.default = ""
+        flag.description = "Suffix specified using a long flag and descriptive argument."
+      end
+
+      cmd.flags.add do |flag|
+        flag.name = "suffix-dir-on-short"
+        flag.short = "-s DIR"
         flag.long = "--suffix"
         flag.default = ""
-        flag.description = "Suffix of something."
+        flag.description = "Suffix specified using a short flag with descriptive argument and long flag."
+      end
+
+      cmd.flags.add do |flag|
+        flag.name = "suffix-dir-on-long"
+        flag.short = "-s"
+        flag.long = "--suffix DIR"
+        flag.default = ""
+        flag.description = "Suffix specified using a long flag with descriptive argument and short flag."
+      end
+
+      cmd.flags.add do |flag|
+        flag.name = "suffix-dir-on-both"
+        flag.short = "-s DIR"
+        flag.long = "--suffix DIR"
+        flag.default = ""
+        flag.description = "Suffix specified using a long flag with descriptive argument and short flag with descriptive argument."
       end
 
       cmd.flags.add do |flag|
@@ -68,12 +98,16 @@ describe Commander do
         kill <pid>      Kills server by pid.
 
       Flags:
-        -e, --env      The environment to run in. default: 'development'
-        -h, --help     Help for this command.
-        -p, --port     The port to bind to. default: 8080
-        -s, --suffix   Suffix of something.
-        -t, --timeout  The wait time before dropping the connection. default: 29.5
-        -v, --verbose  Enable more verbose logging.
+        -e, --env         The environment to run in. default: 'development'
+        -h, --help        Help for this command.
+        -p, --port        The port to bind to. default: 8080
+        -s, --suffix DIR  Suffix specified using a long flag with descriptive argument and short flag with descriptive argument.
+        -s, --suffix DIR  Suffix specified using a long flag with descriptive argument and short flag.
+        -s, --suffix DIR  Suffix specified using a short flag with descriptive argument and long flag.
+            --suffix DIR  Suffix specified using a long flag and descriptive argument.
+        -s DIR            Suffix specified using a short flag and descriptive argument.
+        -t, --timeout     The wait time before dropping the connection. default: 29.5
+        -v, --verbose     Enable more verbose logging.
     EOS
 
     cli.commands.to_a[1].help.should eq <<-EOS

src/commander/command.cr

@@ -151,6 +151,8 @@ class Commander::Command
         result += "    #{flag.long}"
       end
 
+      result += " #{flag.arg}" if flag.arg
+
       description =
         case flag.default
         when Bool, ""

src/commander/flag.cr

@@ -7,16 +7,17 @@ class Commander::Flag
   LONG_PATTERN  = /^\-\-[a-zA-Z0-9-]+$/
 
   property name : String
-  property short : String
-  property long : String
   property default : Types
+  setter short : String
+  setter long : String
   property description : String
   property persistent : Bool
 
   def initialize
     @name = ""
     @short = ""
     @long = ""
+    @arg = ""
     @description = ""
     @default = nil
     @persistent = false
@@ -27,6 +28,27 @@ class Commander::Flag
     yield self
   end
 
+  def short : String
+    @short.split[0]? || ""
+  end
+
+  def long : String
+    @long.split[0]? || ""
+  end
+
+  def arg : String | Nil
+    long_segments = @long.split[1..-1]? || Array(String).new
+    short_segments = @short.split[1..-1]? || Array(String).new
+
+    if long_segments.size > 0
+      long_segments.join(" ")
+    elsif short_segments.size > 0
+      short_segments.join(" ")
+    else
+      nil
+    end
+  end
+
   protected def type
     default.class
   end