refactor(rtt): use proto Duration, add tests

2026-08-26 19:13:34 +00:00 · 2026-04-20 11:36:44 +10:00
parent 8d023f5c53
commit 84990ad692
10 changed files with 387 additions and 144 deletions
@@ -0,0 +1,174 @@
+package corrosion
+
+import (
+	"math"
+	"net/netip"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestComputeRTTStatsMs(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		name       string
+		samples    []float64
+		wantMedian float64
+		wantStdDev float64
+	}{
+		{
+			name:       "single sample",
+			samples:    []float64{42},
+			wantMedian: 42,
+			wantStdDev: 0,
+		},
+		{
+			name:       "two samples (even, averaged)",
+			samples:    []float64{10, 20},
+			wantMedian: 15,
+			// Population stddev: variance = ((10-15)^2 + (20-15)^2)/2 = 25; sqrt = 5.
+			wantStdDev: 5,
+		},
+		{
+			name:       "three samples (odd, middle)",
+			samples:    []float64{3, 1, 2},
+			wantMedian: 2,
+			// Mean = 2; variance = (1+0+1)/3 = 0.666...; stddev = sqrt(2/3).
+			wantStdDev: math.Sqrt(2.0 / 3.0),
+		},
+		{
+			name:       "four samples (even, averaged)",
+			samples:    []float64{1, 2, 3, 4},
+			wantMedian: 2.5,
+			// Mean = 2.5; variance = (2.25+0.25+0.25+2.25)/4 = 1.25; stddev = sqrt(1.25).
+			wantStdDev: math.Sqrt(1.25),
+		},
+		{
+			// Verifies that unsorted input is sorted before picking the median.
+			name:       "unsorted input",
+			samples:    []float64{100, 1, 50},
+			wantMedian: 50,
+			// Mean = 151/3. Variance = ((149^2 + 148^2 + 1^2) / 9) / 3.
+			wantStdDev: math.Sqrt(float64(149*149+148*148+1) / 9.0 / 3.0),
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			median, stdDev := computeRTTStatsMs(tt.samples)
+			assert.InDelta(t, tt.wantMedian, median, 1e-9, "median")
+			assert.InDelta(t, tt.wantStdDev, stdDev, 1e-9, "stdDev")
+		})
+	}
+}
+
+func TestParseClusterMemberRTT(t *testing.T) {
+	validState := map[string]any{"addr": "[fdcc:b618:5034:7afa:172a:1452:f2de:3c99]:51001"}
+
+	tests := []struct {
+		name      string
+		input     map[string]any
+		wantAddr  string
+		wantRTTs  []float64
+		wantErr   bool
+		errSubstr string
+	}{
+		{
+			name: "valid state and rtts",
+			input: map[string]any{
+				"state": validState,
+				"rtts":  []any{float64(10), float64(20), float64(30)},
+			},
+			wantAddr: "[fdcc:b618:5034:7afa:172a:1452:f2de:3c99]:51001",
+			wantRTTs: []float64{10, 20, 30},
+		},
+		{
+			name: "missing rtts key is not an error",
+			input: map[string]any{
+				"state": validState,
+			},
+			wantAddr: "[fdcc:b618:5034:7afa:172a:1452:f2de:3c99]:51001",
+			wantRTTs: nil,
+		},
+		{
+			name: "null rtts value is not an error",
+			input: map[string]any{
+				"state": validState,
+				"rtts":  nil,
+			},
+			wantAddr: "[fdcc:b618:5034:7afa:172a:1452:f2de:3c99]:51001",
+			wantRTTs: nil,
+		},
+		{
+			name: "empty rtts array is not an error",
+			input: map[string]any{
+				"state": validState,
+				"rtts":  []any{},
+			},
+			wantAddr: "[fdcc:b618:5034:7afa:172a:1452:f2de:3c99]:51001",
+			wantRTTs: nil,
+		},
+		{
+			name: "non-array rtts",
+			input: map[string]any{
+				"state": validState,
+				"rtts":  "not-an-array",
+			},
+			wantErr:   true,
+			errSubstr: "invalid 'rtts' field type",
+		},
+		{
+			name: "non-number element in rtts",
+			input: map[string]any{
+				"state": validState,
+				"rtts":  []any{float64(10), "bad"},
+			},
+			wantErr:   true,
+			errSubstr: "invalid rtt value type",
+		},
+		{
+			name:      "missing state",
+			input:     map[string]any{"rtts": []any{float64(1)}},
+			wantErr:   true,
+			errSubstr: "missing or invalid 'state' field",
+		},
+		{
+			name: "missing addr in state",
+			input: map[string]any{
+				"state": map[string]any{},
+				"rtts":  []any{float64(1)},
+			},
+			wantErr:   true,
+			errSubstr: "missing or invalid 'addr' field",
+		},
+		{
+			name: "invalid addr format",
+			input: map[string]any{
+				"state": map[string]any{"addr": "not-an-addr"},
+				"rtts":  []any{float64(1)},
+			},
+			wantErr:   true,
+			errSubstr: "parse 'addr' field",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			addr, rtts, err := parseClusterMemberRTT(tt.input)
+			if tt.wantErr {
+				require.Error(t, err)
+				assert.Contains(t, err.Error(), tt.errSubstr)
+				return
+			}
+			require.NoError(t, err)
+			assert.Equal(t, tt.wantAddr, addr.String())
+			assert.Equal(t, tt.wantRTTs, rtts)
+
+			// Sanity: the parsed addr is a valid AddrPort.
+			_, perr := netip.ParseAddrPort(addr.String())
+			assert.NoError(t, perr)
+		})
+	}
+}