Dns.join (#944)

* Add dnsutil.Join

* Create dnsutil.Join

Create Join helper function and move bits in the code over.

1 files changed, 20 insertions, 0 deletions

diff --git a/middleware/pkg/dnsutil/join_test.go b/middleware/pkg/dnsutil/join_test.go
new file mode 100644
index 000000000..26eeb5897
--- /dev/null
+++ b/middleware/pkg/dnsutil/join_test.go
@@ -0,0 +1,20 @@
+package dnsutil
+
+import "testing"
+
+func TestJoin(t *testing.T) {
+	tests := []struct {
+		in  []string
+		out string
+	}{
+		{[]string{"bla", "bliep", "example", "org"}, "bla.bliep.example.org."},
+		{[]string{"example", "."}, "example."},
+		{[]string{"."}, "."},
+	}
+
+	for i, tc := range tests {
+		if x := Join(tc.in); x != tc.out {
+			t.Errorf("Test %d, expected %s, got %s", i, tc.out, x)
+		}
+	}
+}