hashcode: "Strings" function for hashing slices of strings

helper/hashcode/hashcode.go

@@ -1,6 +1,8 @@
 package hashcode
 
 import (
+	"bytes"
+	"fmt"
 	"hash/crc32"
 )
 
@@ -20,3 +22,14 @@ func String(s string) int {
 	// v == MinInt
 	return 0
 }
+
+// Strings hashes a list of strings to a unique hashcode.
+func Strings(strings []string) string {
+	var buf bytes.Buffer
+
+	for _, s := range strings {
+		buf.WriteString(fmt.Sprintf("%s-", s))
+	}
+
+	return fmt.Sprintf("%d", String(buf.String()))
+}

helper/hashcode/hashcode_test.go

@@ -15,6 +15,17 @@ func TestString(t *testing.T) {
 	}
 }
 
+func TestStrings(t *testing.T) {
+	v := []string{"hello", ",", "world"}
+	expected := Strings(v)
+	for i := 0; i < 100; i++ {
+		actual := Strings(v)
+		if actual != expected {
+			t.Fatalf("bad: %#v\n\t%#v", actual, expected)
+		}
+	}
+}
+
 func TestString_positiveIndex(t *testing.T) {
 	// "2338615298" hashes to uint32(2147483648) which is math.MinInt32
 	ips := []string{"192.168.1.3", "192.168.1.5", "2338615298"}