Initial commit

checker/dns_test.go

@@ -0,0 +1,50 @@
+package checker
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestJoinSubdomain(t *testing.T) {
+	cases := []struct {
+		sub, origin, want string
+	}{
+		{"", "example.com", "example.com."},
+		{"@", "example.com", "example.com."},
+		{"www", "example.com", "www.example.com."},
+		{"www.", "example.com.", "www.example.com."},
+		{"www.example.com", "example.com", "www.example.com."},
+		{"example.com", "example.com", "example.com."},
+	}
+	for _, c := range cases {
+		got := joinSubdomain(c.sub, c.origin)
+		if got != c.want {
+			t.Errorf("joinSubdomain(%q,%q) = %q, want %q", c.sub, c.origin, got, c.want)
+		}
+	}
+}
+
+func TestResolvers_Explicit(t *testing.T) {
+	got := resolvers("1.1.1.1, 8.8.8.8:5353 ,")
+	want := []string{"1.1.1.1:53", "8.8.8.8:5353"}
+	if !reflect.DeepEqual(got, want) {
+		t.Errorf("got %v, want %v", got, want)
+	}
+}
+
+func TestResolvers_FallbackList(t *testing.T) {
+	// We don't trust /etc/resolv.conf to be absent in all CI environments,
+	// but the empty-input path must always return at least one resolver.
+	got := resolvers("")
+	if len(got) == 0 {
+		t.Fatal("expected at least one resolver")
+	}
+}
+
+func TestMaxAnswerRecords_Constant(t *testing.T) {
+	// Sanity check: don't silently lower the cap to something useless
+	// without updating tests / behaviour.
+	if maxAnswerRecords < 8 {
+		t.Errorf("maxAnswerRecords=%d is suspiciously low", maxAnswerRecords)
+	}
+}