Shell#ask: support a noecho option for stdin

lib/thor/shell/basic.rb

@@ -1,4 +1,5 @@
 require 'tempfile'
+require 'io/console'
 
 class Thor
   module Shell
@@ -40,11 +41,16 @@ def padding=(value)
       # they will be shown a message stating that one of those answers
       # must be given and re-asked the question.
       #
+      # If asking for sensitive information, the :echo option can be set
+      # to false to mask user input from $stdin.
+      #
       # ==== Example
       # ask("What is your name?")
       #
       # ask("What is your favorite Neopolitan flavor?", :limited_to => ["strawberry", "chocolate", "vanilla"])
       #
+      # ask("What is your password?", :echo => false)
+      #
       def ask(statement, *args)
         options = args.last.is_a?(Hash) ? args.pop : {}
         color = args.first
@@ -381,7 +387,12 @@ def ask_simply(statement, color, options)
         default = options[:default]
         message = [statement, ("(#{default})" if default), nil].uniq.join(" ")
         say(message, color)
-        result = stdin.gets
+
+        result = if options[:echo] == false
+          stdin.noecho(&:gets)
+        else
+          stdin.gets
+        end
 
         return unless result
 

spec/shell/basic_spec.rb

@@ -20,6 +20,7 @@ def shell
     it "prints a message to the user and gets the response" do
       $stdout.should_receive(:print).with("Should I overwrite it? ")
       $stdin.should_receive(:gets).and_return('Sure')
+      $stdin.should_not_receive(:noecho).and_return('Sure')
       expect(shell.ask("Should I overwrite it?")).to eq("Sure")
     end
 
@@ -29,6 +30,11 @@ def shell
       expect(shell.ask("")).to eq(nil)
     end
 
+    it "prints a message to the user and does not echo stdin if the echo option is set to false" do
+      $stdout.should_receive(:print).with('What\'s your password? ')
+      $stdin.should_receive(:noecho).and_return('mysecretpass')
+      expect(shell.ask("What's your password?", :echo => false)).to eq("mysecretpass")
+    end
 
     it "prints a message to the user with the available options and determines the correctness of the answer" do
       $stdout.should_receive(:print).with('What\'s your favorite Neopolitan flavor? [strawberry, chocolate, vanilla] ')