Started working on unit tests

Fixed some bugs in the CSVColumn processor

csv_test.go

@@ -0,0 +1,31 @@
+package scriptx_test
+
+import (
+	"testing"
+
+	"github.com/bitfield/script"
+	"github.com/lmika/scriptx"
+)
+
+func TestCSVColumn(t *testing.T) {
+	t.Run("should return named column of CSV input", func(t *testing.T) {
+		verifyPipeLines(t, func(p *script.Pipe) *script.Pipe {
+			return p.Filter(scriptx.CSVColumn("state"))
+		}, []string{
+			"city,state,country",
+			"Melbourne,Vic,AU",
+			"Sydney,NSW,AU",
+			"Canberra,\"Territory, Australian Capital\",AU",
+			"New York,NY,US,Extra,Comments,Allowed",
+			"Missing state is ignored",
+			"# Comment is ignored",
+			"Seattle,WA",
+		}, []string{
+			"Vic",
+			"NSW",
+			"Territory, Australian Capital",
+			"NY",
+			"WA",
+		})
+	})
+}