Add optional eol argument to AchFile#to_s

Closes #49

lib/ach/ach_file.rb

@@ -22,7 +22,8 @@ def initialize data=nil
       end
     end
 
-    def to_s
+    # @param eol [String] Line ending, default to CRLF
+    def to_s eol = "\r\n"
       records = []
       records << @header
 
@@ -51,7 +52,7 @@ def to_s
         @control.entry_hash += batch.control.entry_hash
       end
 
-      records.collect { |r| r.to_ach }.join("\r\n") + "\r\n"
+      records.collect { |r| r.to_ach }.join(eol) + eol
     end
 
     def report

spec/ach/ach_file_spec.rb

@@ -126,5 +126,26 @@ def add_detail batch
         end
       end
     end
+
+    describe 'eol param' do
+      context 'default' do
+        subject(:output) { ach_file.to_s }
+
+        it 'uses CRLF' do
+          expect(output.split("\r\n").length).to eq(10)
+          expect(output[-2..-1]).to eq("\r\n")
+        end
+      end
+
+      context 'param given' do
+        subject(:output) { ach_file.to_s("\n") }
+        it 'uses the param' do
+          expect(output.split("\r\n").length).to eq(1)
+          expect(output.split("\n").length).to eq(10)
+          expect(output[-2..-1]).to_not eq("\r\n")
+          expect(output[-1]).to eq("\n")
+        end
+      end
+    end
   end
 end