Add list function the create list of strings

Add a function to create a human style list of strings, where a comma separates
each entry and the last one add an additional "and" to the text.

text.go

@@ -24,6 +24,7 @@ Package text contains convenience functions for creating strings
 package text
 
 import (
+	"bytes"
 	"fmt"
 	"math/rand"
 	"strconv"
@@ -119,3 +120,19 @@ func Plural(amount int, text ...string) string {
 		return fmt.Sprintf("%s %s", number, text[1])
 	}
 }
+
+// List creates a list of the string entries with commas and an ending "and"
+func List(list []string) string {
+	var buf bytes.Buffer
+	for idx, entry := range list {
+		fmt.Fprint(&buf, entry)
+
+		if idx < len(list)-2 {
+			fmt.Fprint(&buf, ", ")
+		} else if idx < len(list)-1 {
+			fmt.Fprint(&buf, ", and ")
+		}
+	}
+
+	return buf.String()
+}

text_test.go

@@ -95,7 +95,7 @@ var _ = Describe("Generate random strings with fixed length", func() {
 		})
 	})
 
-	Context("creating proper texts", func() {
+	Context("Creating proper plurals", func() {
 		It("should return human readable plurals", func() {
 			Expect(Plural(0, "foobar")).To(BeEquivalentTo("no foobars"))
 			Expect(Plural(1, "foobar")).To(BeEquivalentTo("one foobar"))
@@ -117,4 +117,11 @@ var _ = Describe("Generate random strings with fixed length", func() {
 			Expect(Plural(2, "basis", "bases")).To(BeEquivalentTo("two bases"))
 		})
 	})
+
+	Context("Creating human readable lists", func() {
+		It("should create a human readable list of strings", func() {
+			Expect(List([]string{"one", "two", "three", "four"})).
+				To(BeEquivalentTo("one, two, three, and four"))
+		})
+	})
 })