autopilot: add Median method

autopilot/graph_test.go

@@ -0,0 +1,50 @@
+package autopilot_test
+
+import (
+	"testing"
+
+	"github.com/btcsuite/btcutil"
+	"github.com/lightningnetwork/lnd/autopilot"
+)
+
+// TestMedian tests the Median method.
+func TestMedian(t *testing.T) {
+	t.Parallel()
+
+	testCases := []struct {
+		values []btcutil.Amount
+		median btcutil.Amount
+	}{
+		{
+			values: []btcutil.Amount{},
+			median: 0,
+		},
+		{
+			values: []btcutil.Amount{10},
+			median: 10,
+		},
+		{
+			values: []btcutil.Amount{10, 20},
+			median: 15,
+		},
+		{
+			values: []btcutil.Amount{10, 20, 30},
+			median: 20,
+		},
+		{
+			values: []btcutil.Amount{30, 10, 20},
+			median: 20,
+		},
+		{
+			values: []btcutil.Amount{10, 10, 10, 10, 5000000},
+			median: 10,
+		},
+	}
+
+	for _, test := range testCases {
+		res := autopilot.Median(test.values)
+		if res != test.median {
+			t.Fatalf("expected median %v, got %v", test.median, res)
+		}
+	}
+}