1 files changed, 51 insertions, 0 deletions
diff --git a/test/csv/interface/test_read_write.rb b/test/csv/interface/test_read_write.rb
new file mode 100644
index 0000000000..9ce3553d61
--- /dev/null
+++ b/test/csv/interface/test_read_write.rb
@@ -0,0 +1,51 @@
+# frozen_string_literal: false
+
+require_relative "../helper"
+
+class TestCSVInterfaceReadWrite < Test::Unit::TestCase
+  extend DifferentOFS
+
+  def test_filter
+    rows = [[1, 2, 3], [4, 5]]
+    input = <<-CSV
+1;2;3
+4;5
+    CSV
+    output = ""
+    CSV.filter(input, output,
+               in_col_sep: ";",
+               out_col_sep: ",",
+               converters: :all) do |row|
+      row.map! {|n| n * 2}
+      row << "Added\r"
+    end
+    assert_equal(<<-CSV, output)
+2,4,6,"Added\r"
+8,10,"Added\r"
+    CSV
+  end
+
+  def test_instance_same
+    data = ""
+    assert_equal(CSV.instance(data, col_sep: ";").object_id,
+                 CSV.instance(data, col_sep: ";").object_id)
+  end
+
+  def test_instance_append
+    output = ""
+    CSV.instance(output, col_sep: ";") << ["a", "b", "c"]
+    assert_equal(<<-CSV, output)
+a;b;c
+    CSV
+    CSV.instance(output, col_sep: ";") << [1, 2, 3]
+    assert_equal(<<-CSV, output)
+a;b;c
+1;2;3
+    CSV
+  end
+
+  def test_instance_shortcut
+    assert_equal(CSV.instance,
+                 CSV {|csv| csv})
+  end
+end