Fix surfshark updater and update server data

internal/updater/ips_test.go

@@ -0,0 +1,41 @@
+package updater
+
+import (
+	"net"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func Test_uniqueSortedIPs(t *testing.T) {
+	t.Parallel()
+	testCases := map[string]struct {
+		inputIPs  []net.IP
+		outputIPs []net.IP
+	}{
+		"nil": {
+			inputIPs:  nil,
+			outputIPs: []net.IP{},
+		},
+		"empty": {
+			inputIPs:  []net.IP{},
+			outputIPs: []net.IP{},
+		},
+		"single IPv4": {
+			inputIPs:  []net.IP{{1, 1, 1, 1}},
+			outputIPs: []net.IP{{1, 1, 1, 1}},
+		},
+		"two IPv4s": {
+			inputIPs:  []net.IP{{1, 1, 2, 1}, {1, 1, 1, 1}},
+			outputIPs: []net.IP{{1, 1, 1, 1}, {1, 1, 2, 1}},
+		},
+	}
+	for name, testCase := range testCases {
+		testCase := testCase
+		t.Run(name, func(t *testing.T) {
+			t.Parallel()
+			outputIPs := uniqueSortedIPs(testCase.inputIPs)
+			assert.Equal(t, testCase.outputIPs, outputIPs)
+		})
+	}
+}