Move code to pkg

pkg/middlewares/requestdecorator/hostresolver_test.go

@@ -0,0 +1,51 @@
+package requestdecorator
+
+import (
+	"context"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestCNAMEFlatten(t *testing.T) {
+	testCases := []struct {
+		desc           string
+		resolvFile     string
+		domain         string
+		expectedDomain string
+	}{
+		{
+			desc:           "host request is CNAME record",
+			resolvFile:     "/etc/resolv.conf",
+			domain:         "www.github.com",
+			expectedDomain: "github.com",
+		},
+		{
+			desc:           "resolve file not found",
+			resolvFile:     "/etc/resolv.oops",
+			domain:         "www.github.com",
+			expectedDomain: "www.github.com",
+		},
+		{
+			desc:           "host request is not CNAME record",
+			resolvFile:     "/etc/resolv.conf",
+			domain:         "github.com",
+			expectedDomain: "github.com",
+		},
+	}
+
+	for _, test := range testCases {
+		test := test
+		t.Run(test.desc, func(t *testing.T) {
+			t.Parallel()
+
+			hostResolver := &Resolver{
+				ResolvConfig: test.resolvFile,
+				ResolvDepth:  5,
+			}
+
+			flatH := hostResolver.CNAMEFlatten(context.Background(), test.domain)
+			assert.Equal(t, test.expectedDomain, flatH)
+		})
+	}
+}