Cover the loss window, rate window, error taxonomy and formatters with tests

loss_test.go

@@ -0,0 +1,91 @@
+package main
+
+import "testing"
+
+func newWindow() *lossWindow {
+	w := newLossWindows(1)
+	return &w[0]
+}
+
+func TestLossWindowContiguousLosesNothing(t *testing.T) {
+	w := newWindow()
+	for seq := uint64(0); seq < lossSlots+1000; seq++ {
+		w.observe(seq)
+	}
+	if got := w.lost.Load(); got != 0 {
+		t.Errorf("lost = %d, want 0", got)
+	}
+	if got := w.late.Load(); got != 0 {
+		t.Errorf("late = %d, want 0", got)
+	}
+}
+
+func TestLossWindowCountsGapOnceEvicted(t *testing.T) {
+	w := newWindow()
+	for seq := uint64(0); seq < lossSlots+1000; seq++ {
+		if seq == 100 {
+			continue
+		}
+		w.observe(seq)
+	}
+	if got := w.lost.Load(); got != 1 {
+		t.Errorf("lost = %d, want 1", got)
+	}
+}
+
+// Arriving out of order inside the window is not loss: a sequence is only
+// judged once it falls out the far end.
+func TestLossWindowOutOfOrderIsNotLoss(t *testing.T) {
+	w := newWindow()
+	for seq := uint64(99); ; seq-- {
+		w.observe(seq)
+		if seq == 0 {
+			break
+		}
+	}
+	for seq := uint64(100); seq < lossSlots+1000; seq++ {
+		w.observe(seq)
+	}
+	if got := w.lost.Load(); got != 0 {
+		t.Errorf("lost = %d, want 0", got)
+	}
+}
+
+// The other branch of evict: a jump past a whole window writes off everything
+// the window held plus the sequences that never landed in it at all.
+func TestLossWindowJumpBeyondWindow(t *testing.T) {
+	w := newWindow()
+	w.observe(0)
+	w.observe(200000)
+
+	// Everything below the new base except the one sequence that was seen.
+	want := uint64(200000 - lossSlots + 1 - 1)
+	if got := w.lost.Load(); got != want {
+		t.Errorf("lost = %d, want %d", got, want)
+	}
+	if got := w.late.Load(); got != 0 {
+		t.Errorf("late = %d, want 0", got)
+	}
+}
+
+func TestLossWindowBelowBaseIsLate(t *testing.T) {
+	w := newWindow()
+	w.observe(100000)
+	w.observe(1000)
+	if got := w.late.Load(); got != 1 {
+		t.Errorf("late = %d, want 1", got)
+	}
+	if got := w.lost.Load(); got != 0 {
+		t.Errorf("lost = %d, want 0", got)
+	}
+}
+
+// The first sequence seen starts the window half a span below it, so frames
+// another worker is still holding land inside rather than arriving late.
+func TestLossWindowStartsHalfAWindowBack(t *testing.T) {
+	w := newWindow()
+	w.observe(100000)
+	if w.base != 100000-lossSlots/2 {
+		t.Errorf("base = %d, want %d", w.base, 100000-lossSlots/2)
+	}
+}

main_test.go

@@ -1,6 +1,68 @@
 package main
 
-import "testing"
+import (
+	"testing"
+	"time"
+)
+
+func TestRateWindowLatestNeedsTwoBuckets(t *testing.T) {
+	w := newRateWindow(4)
+	if got := w.latest(rxRatePPS); got != 0 {
+		t.Errorf("empty ring gave %v, want 0", got)
+	}
+	w.push(counterSet{t: time.Now(), s: sample{rxFrames: 100}})
+	if got := w.latest(rxRatePPS); got != 0 {
+		t.Errorf("one bucket gave %v, want 0", got)
+	}
+}
+
+// The newest pair alone, so a step in the rate shows at once instead of being
+// averaged against everything still in the ring.
+func TestRateWindowLatestUsesNewestPair(t *testing.T) {
+	w := newRateWindow(4)
+	t0 := time.Now()
+	w.push(counterSet{t: t0, s: sample{rxFrames: 100}})
+	w.push(counterSet{t: t0.Add(time.Second), s: sample{rxFrames: 300}})
+	if got := w.latest(rxRatePPS); got != 200 {
+		t.Errorf("rate = %v, want 200", got)
+	}
+	w.push(counterSet{t: t0.Add(2 * time.Second), s: sample{rxFrames: 400}})
+	if got := w.latest(rxRatePPS); got != 100 {
+		t.Errorf("rate = %v, want 100 rather than the mean of the ring", got)
+	}
+}
+
+func TestRateWindowLatestIgnoresZeroSpan(t *testing.T) {
+	w := newRateWindow(4)
+	t0 := time.Now()
+	w.push(counterSet{t: t0, s: sample{rxFrames: 100}})
+	w.push(counterSet{t: t0, s: sample{rxFrames: 300}})
+	if got := w.latest(rxRatePPS); got != 0 {
+		t.Errorf("rate = %v, want 0", got)
+	}
+}
+
+// Which counter feeds which bucket is the whole taxonomy the panel reports, so
+// it is pinned here rather than left to whoever reads errsBetween next.
+func TestErrsBetweenBuckets(t *testing.T) {
+	n := counterSet{
+		s: sample{
+			lost: 1, late: 7,
+			crcErr: 2, badMagic: 3, badLen: 4,
+			txErrs: 6, rxErrs: 5,
+		},
+		drops: 9,
+		nic:   8,
+	}
+	got := errsBetween(counterSet{}, n)
+	want := errs{lost: 1, corrupt: 2 + 3 + 4, link: 8 + 5, internal: 9 + 7 + 6}
+	if got != want {
+		t.Errorf("errsBetween = %+v, want %+v", got, want)
+	}
+	if got.total() != 45 {
+		t.Errorf("total = %d, want 45", got.total())
+	}
+}
 
 // A reset re-bases from a fresh capture while the ring still holds buckets from
 // just before it, so the newest bucket must not be left behind the new origin.

probe_test.go

@@ -0,0 +1,25 @@
+package main
+
+import "testing"
+
+func stamped(min, floor int64) view {
+	return view{cable: cableView{min: min, floor: floor, ok: true}}
+}
+
+// Averaged across directions, since one direction alone carries a phy asymmetry
+// that swamps the cable.
+func TestCableMetresAveragesDirections(t *testing.T) {
+	m, ok := cableMetres([]view{stamped(1000, 900), stamped(1100, 900)}, 5)
+	if !ok || m != 30 {
+		t.Errorf("cableMetres = %v, %v; want 30, true", m, ok)
+	}
+}
+
+func TestCableMetresNeedsEveryDirection(t *testing.T) {
+	if _, ok := cableMetres(nil, 5); ok {
+		t.Error("no views should not yield a length")
+	}
+	if _, ok := cableMetres([]view{stamped(1000, 900), {}}, 5); ok {
+		t.Error("a direction with no stamp yet should not yield a length")
+	}
+}

render_test.go

@@ -0,0 +1,108 @@
+package main
+
+import (
+	"testing"
+	"time"
+)
+
+func TestScaleSI(t *testing.T) {
+	for _, c := range []struct {
+		in   float64
+		want string
+	}{
+		{0, "0.00"},
+		{999, "999.00"},
+		{1000, "1.00 k"},
+		{1234567, "1.23 M"},
+		{1e12, "1.00 T"},
+		{1e15, "1.00 P"},
+	} {
+		if got := scaleSI(c.in); got != c.want {
+			t.Errorf("scaleSI(%v) = %q, want %q", c.in, got, c.want)
+		}
+	}
+}
+
+// Below a thousand a count is the count, since two decimals on a quantity that
+// cannot have them read as precision that is not there.
+func TestScaleCount(t *testing.T) {
+	for _, c := range []struct {
+		in   uint64
+		want string
+	}{
+		{0, "0"},
+		{999, "999"},
+		{1000, "1.00 k"},
+	} {
+		if got := scaleCount(c.in); got != c.want {
+			t.Errorf("scaleCount(%d) = %q, want %q", c.in, got, c.want)
+		}
+	}
+}
+
+func TestScaleTime(t *testing.T) {
+	for _, c := range []struct {
+		in   time.Duration
+		want string
+	}{
+		{1500 * time.Millisecond, "1.50 s"},
+		{90 * time.Second, "1.50 m"},
+		{90 * time.Minute, "1.50 h"},
+		{36 * time.Hour, "1.50 d"},
+	} {
+		if got := scaleTime(c.in); got != c.want {
+			t.Errorf("scaleTime(%v) = %q, want %q", c.in, got, c.want)
+		}
+	}
+}
+
+func TestCommas(t *testing.T) {
+	for _, c := range []struct {
+		in   uint64
+		want string
+	}{
+		{0, "0"},
+		{999, "999"},
+		{1000, "1,000"},
+		{1234567, "1,234,567"},
+	} {
+		if got := commas(c.in); got != c.want {
+			t.Errorf("commas(%d) = %q, want %q", c.in, got, c.want)
+		}
+	}
+}
+
+// The table only lines up if colour codes are not counted as width.
+func TestPadIgnoresColour(t *testing.T) {
+	if got := visWidth(paint("ok", cGreen)); got != 2 {
+		t.Errorf("visWidth = %d, want 2", got)
+	}
+	if got := visWidth(pad(paint("ok", cGreen), 6, true)); got != 6 {
+		t.Errorf("padded width = %d, want 6", got)
+	}
+}
+
+// The break between the two halves of the row has to be the same width on the
+// header, the rule and every value line, or the columns drift apart.
+func TestStreamTableBreakAligns(t *testing.T) {
+	tbl := &streamTable{cols: intervalCols}
+	lines := tbl.headerLines()
+	row := tbl.emit(make([]string, len(intervalCols)))
+	widths := map[string]int{}
+	for _, l := range append(lines, row...) {
+		widths[l] = visWidth(l)
+	}
+	var first int
+	for _, w := range widths {
+		if first == 0 {
+			first = w
+			continue
+		}
+		if w != first {
+			t.Fatalf("header and value lines disagree on width: %v", widths)
+		}
+	}
+	if first != tbl.width() {
+		t.Errorf("lines are %d wide, width() reports %d", first, tbl.width())
+	}
+}

ui_test.go

@@ -0,0 +1,28 @@
+package main
+
+import "testing"
+
+func TestGridCellFullRow(t *testing.T) {
+	x0, w0 := gridCell(0, 2, 0, 100)
+	x1, w1 := gridCell(1, 2, 0, 100)
+	if w0 != w1 {
+		t.Errorf("cells differ in width: %d vs %d", w0, w1)
+	}
+	if x0 != 0 {
+		t.Errorf("first cell x = %d, want 0", x0)
+	}
+	if x1+w1 != 100 {
+		t.Errorf("row ends at %d, want 100", x1+w1)
+	}
+	if got := x1 - (x0 + w0); got != chipGap {
+		t.Errorf("gap between cells = %d, want %d", got, chipGap)
+	}
+}
+
+// A last row that does not fill the grid is centred.
+func TestGridCellShortLastRow(t *testing.T) {
+	cx, cw := gridCell(2, 3, 0, 100)
+	if left, right := cx, 100-(cx+cw); left != right {
+		t.Errorf("lone cell has %d left and %d right, want centred", left, right)
+	}
+}