From 837d2735f22d33b211b1d7756c90da87c65ba906 Mon Sep 17 00:00:00 2001
From: Aleksey Strizhak <alexei.mifrill.strizhak@gmail.com>
Date: Wed, 17 Oct 2018 16:41:35 +0500
Subject: [PATCH] fixes #389 #to_csv changed predefined arguments and add
 documentation

---
 README.md                 | 8 ++++++++
 lib/roo/formatters/csv.rb | 2 +-
 spec/lib/roo/base_spec.rb | 9 ++++++++-
 3 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/README.md b/README.md
index 639a2daa..039832dc 100644
--- a/README.md
+++ b/README.md
@@ -156,6 +156,14 @@ sheet.to_xml
 sheet.to_yaml
 ```
 
+`#to_csv` acceptable for the parameters:
+
+    # puts csv format content into a specified file
+    sheet.to_csv(filename: "/path/file.txt)
+
+    # specify the custom separator for the content 
+    sheet.to_csv(separator: ":")      
+
 ### Excel (xlsx and xlsm) Support
 
 Stream rows from an Excelx spreadsheet.
diff --git a/lib/roo/formatters/csv.rb b/lib/roo/formatters/csv.rb
index 3181f091..46afbc6c 100644
--- a/lib/roo/formatters/csv.rb
+++ b/lib/roo/formatters/csv.rb
@@ -1,7 +1,7 @@
 module Roo
   module Formatters
     module CSV
-      def to_csv(filename = nil, separator = ",", sheet = default_sheet)
+      def to_csv(sheet = default_sheet, separator: ",", filename: nil)
         if filename
           File.open(filename, "w") do |file|
             write_csv_content(file, sheet, separator)
diff --git a/spec/lib/roo/base_spec.rb b/spec/lib/roo/base_spec.rb
index 76cefcc4..d8314784 100644
--- a/spec/lib/roo/base_spec.rb
+++ b/spec/lib/roo/base_spec.rb
@@ -268,8 +268,15 @@ def sheets
       expect(spreadsheet.to_csv).to eq(expected_csv)
     end
 
+    it 'should convert the spreadsheet to csv and put it into a file' do
+      file = Tempfile.new("test")
+
+      expect(spreadsheet.to_csv(filename: file)).to be_truthy
+      expect(file.read).to eq(expected_csv)
+    end
+
     it 'should convert the spreadsheet to csv using the separator when is passed on the parameter' do
-      expect(spreadsheet.to_csv(nil, ';')).to eq(expected_csv_with_semicolons)
+      expect(spreadsheet.to_csv(separator: ';')).to eq(expected_csv_with_semicolons)
     end
   end
 end