stat/card: make tests parallel

stat/card/card_test.go

@@ -73,9 +73,15 @@ func mustCounter(c counter, err error) counter {
 }
 
 func TestCounters(t *testing.T) {
-	var dst []byte
+	t.Parallel()
+
 	for _, test := range counterTests {
+		test := test
+		t.Run(test.name, func(t *testing.T) {
+			t.Parallel()
+
 			rnd := rand.New(rand.NewSource(1))
+			var dst []byte
 			c := test.counter()
 			for i := 0; i < int(test.count); i++ {
 				dst = strconv.AppendUint(dst[:0], rnd.Uint64(), 16)
@@ -96,16 +102,22 @@ func TestCounters(t *testing.T) {
 			if got := c.Count(); !floats.EqualWithinRel(got, test.count, test.tol) {
 				t.Errorf("unexpected count for %s: got:%.0f want:%.0f", test.name, got, test.count)
 			}
+		})
 	}
 }
 
 func TestUnion(t *testing.T) {
-	var dst []byte
+	t.Parallel()
+
 	for _, test := range counterTests {
 		if strings.HasPrefix(test.name, "exact") {
 			continue
 		}
+		test := test
+		t.Run(test.name, func(t *testing.T) {
+			t.Parallel()
 			rnd := rand.New(rand.NewSource(1))
+			var dst []byte
 			var cs [2]counter
 			for j := range cs {
 				cs[j] = test.counter()
@@ -140,6 +152,7 @@ func TestUnion(t *testing.T) {
 			if got := u.Count(); !floats.EqualWithinRel(got, 2*test.count, 2*test.tol) {
 				t.Errorf("unexpected count for %s: got:%.0f want:%.0f", test.name, got, 2*test.count)
 			}
+		})
 	}
 }
 
@@ -167,6 +180,8 @@ func mustResetCounter(c resetCounter, err error) resetCounter {
 }
 
 func TestResetCounters(t *testing.T) {
+	t.Parallel()
+
 	var dst []byte
 	for _, test := range counterResetTests {
 		c := test.resetCounter()
@@ -255,6 +270,8 @@ func mustCounterEncoder(c counterEncoder, err error) counterEncoder {
 }
 
 func TestBinaryEncoding(t *testing.T) {
+	t.Parallel()
+
 	RegisterHash(fnv.New32a)
 	RegisterHash(fnv.New64a)
 	defer func() {
@@ -324,6 +341,8 @@ var invalidRegisterTests = []struct {
 }
 
 func TestRegisterInvalid(t *testing.T) {
+	t.Parallel()
+
 	for _, test := range invalidRegisterTests {
 		var r interface{}
 		func() {
@@ -356,6 +375,8 @@ var rhoQTests = []struct {
 }
 
 func TestRhoQ(t *testing.T) {
+	t.Parallel()
+
 	for _, test := range rhoQTests {
 		got := rho32q(uint32(test.bits), test.q)
 		if got != test.want {