Add more Spec command test coverage

Change STDIN to $stdin so it can be reassigned
Use UI.puts instead of print
Add test coverage for Spec#choose_from_array
Fix off by one issue in Spec#choose_from_array

Closes #1675

lib/cocoapods/command/spec.rb

@@ -300,10 +300,10 @@ module Pod
           UI.puts "#{ index + 1 }: #{ item }"
         end
 
-        print message
+        UI.puts message
 
-        index = STDIN.gets.chomp.to_i - 1
-        if index < 0 || index > array.count
+        index = $stdin.gets.chomp.to_i - 1
+        if index < 0 || index > array.count - 1
           raise Informative, "#{ index + 1 } is invalid [1-#{ array.count }]"
         else
           index

spec/functional/command/spec_spec.rb

@@ -212,9 +212,10 @@ module Pod
       end
 
       it "cats the first podspec from all podspecs" do
-        STDIN = StringIO.new("1\n", 'r')
+        $stdin = StringIO.new("1\n", 'r')
         run_command('spec', 'cat', '--show-all', 'AFNetworking')
         UI.output.should.include fixture('spec-repos/master/AFNetworking/1.2.0/AFNetworking.podspec').read
+        $stdin = STDIN
       end
     end
 
@@ -229,13 +230,13 @@ module Pod
 
     describe "Private helpers" do
 
-      describe "#get_path_of_spec" do
+      before do
+        # TODO Use class methods
+        @sut = Command::Spec.new(CLAide::ARGV.new([]))
 
-        before do
-          # TODO Use class methods
-          @sut = Command::Spec.new(CLAide::ARGV.new([]))
+      end
 
-        end
+      describe "#get_path_of_spec" do
 
         it "returns the path of the specification with the given name" do
           path = @sut.send(:get_path_of_spec, 'AFNetworking')
@@ -244,6 +245,26 @@ module Pod
 
       end
 
+      describe "#choose_from_array" do
+
+        it "should return a valid index for the given array" do
+          $stdin = StringIO.new("1\n", 'r')
+          index = @sut.send(:choose_from_array, ['item1', 'item2', 'item3'], 'A message')
+          UI.output.should.include "1: item1\n2: item2\n3: item3\nA message\n"
+          index.should == 0
+          $stdin = STDIN
+        end
+
+        it "should raise when the index is out of bounds" do
+          $stdin = StringIO.new("4\n", 'r')
+          lambda { @sut.send(:choose_from_array, ['item1', 'item2', 'item3'], 'A message') }.should.raise Pod::Informative
+          $stdin = StringIO.new("0\n", 'r')
+          lambda { @sut.send(:choose_from_array, ['item1', 'item2', 'item3'], 'A message') }.should.raise Pod::Informative
+          $stdin = STDIN
+        end
+
+      end
+
     end
 
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