Support two-argument procs for reducer-style arguments. This allows CLI options which can be repeated.

2 files changed, 22 insertions, 1 deletions

diff --git a/lib/mixlib/cli.rb b/lib/mixlib/cli.rb
index 31e44be..3e72f77 100644
--- a/lib/mixlib/cli.rb
+++ b/lib/mixlib/cli.rb
@@ -281,7 +281,18 @@ module Mixlib
 
           parse_block =
             Proc.new() do |c|
-              config[opt_key] = (opt_val[:proc] && opt_val[:proc].call(c)) || c
+              config[opt_key] = if opt_val[:proc]
+                if opt_val[:proc].arity == 2
+                  # New hotness to allow for reducer-style procs.
+                  opt_val[:proc].call(c, config[opt_key])
+                else
+                  # Older single-argument proc.
+                  opt_val[:proc].call(c)
+                end
+              else
+                # No proc.
+                c
+              end
               puts opts if opt_val[:show_options]
               exit opt_val[:exit] if opt_val[:exit]
             end
diff --git a/spec/mixlib/cli_spec.rb b/spec/mixlib/cli_spec.rb
index 39b1eb1..0115672 100644
--- a/spec/mixlib/cli_spec.rb
+++ b/spec/mixlib/cli_spec.rb
@@ -149,6 +149,16 @@ describe Mixlib::CLI do
         @cli.config[:number].should == 4
       end
 
+      it "should pass the existing value to two-argument procs" do
+        TestCLI.option(:number,
+          :short => "-n NUMBER",
+          :proc => Proc.new { |value, existing| existing ||= []; existing << value; existing }
+        )
+        @cli = TestCLI.new
+        @cli.parse_options([ "-n", "2", "-n", "3" ])
+        @cli.config[:number].should == ["2", "3"]
+      end
+
       it "should set the corresponding config value to true for boolean arguments" do
         TestCLI.option(:i_am_boolean, :short => "-i", :boolean => true)
         @cli = TestCLI.new