Cleanup of img_dir and testing of input_file.rb

spec/args/input_file_spec.rb

@@ -0,0 +1,21 @@
+require 'spec_helper'
+require 'squib/args/input_file'
+
+describe Squib::Args::InputFile do
+  subject(:ifile) {Squib::Args::InputFile.new}
+
+  context 'validate_file' do
+
+    it 'allows a file if it exists' do
+      args = {file: __FILE__} # I code therefore I am.
+      ifile.load!(args, expand_by: 1)
+      expect(ifile).to have_attributes(file: [File.expand_path(__FILE__)])
+    end
+
+    it 'raises on non-existent file' do
+      args = {file: 'foo.rb'}
+      expect { ifile.load!(args, expand_by: 1) }.to raise_error
+    end
+
+  end
+end