CNAME flattening

hostresolver/hostresolver_test.go

@@ -0,0 +1,61 @@
+package hostresolver
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestCNAMEFlatten(t *testing.T) {
+	testCase := []struct {
+		desc           string
+		resolvFile     string
+		domain         string
+		expectedDomain string
+		isCNAME        bool
+	}{
+		{
+			desc:           "host request is CNAME record",
+			resolvFile:     "/etc/resolv.conf",
+			domain:         "www.github.com",
+			expectedDomain: "github.com",
+			isCNAME:        true,
+		},
+		{
+			desc:           "resolve file not found",
+			resolvFile:     "/etc/resolv.oops",
+			domain:         "www.github.com",
+			expectedDomain: "www.github.com",
+			isCNAME:        false,
+		},
+		{
+			desc:           "host request is not CNAME record",
+			resolvFile:     "/etc/resolv.conf",
+			domain:         "github.com",
+			expectedDomain: "github.com",
+			isCNAME:        false,
+		},
+	}
+
+	for _, test := range testCase {
+		test := test
+		t.Run(test.desc, func(t *testing.T) {
+			t.Parallel()
+
+			hostResolver := &Resolver{
+				ResolvConfig: test.resolvFile,
+				ResolvDepth:  5,
+			}
+
+			reqH, flatH := hostResolver.CNAMEFlatten(test.domain)
+			assert.Equal(t, test.domain, reqH)
+			assert.Equal(t, test.expectedDomain, flatH)
+
+			if test.isCNAME {
+				assert.NotEqual(t, test.expectedDomain, reqH)
+			} else {
+				assert.Equal(t, test.expectedDomain, reqH)
+			}
+		})
+	}
+}