update tests

Change-Id: I2d7f4a902877c209b6aa793f108856b750f25d8b

Author: mateusz834

src/internal/chacha8rand/rand_test.go

@@ -31,20 +31,35 @@ func TestOutput(t *testing.T) {
 	}
 }
 
-func TestOutputBytes(t *testing.T) {
-	var s State
-	s.Init(seed)
-
+func TestFillRand(t *testing.T) {
 	expect := make([]byte, 0, len(output)*8)
 	for _, v := range output {
 		expect = byteorder.LeAppendUint64(expect, v)
 	}
 
-	got := make([]byte, len(expect))
-	s.FillRand(got)
+	cases := []struct {
+		expect [][]byte
+	}{
+		{[][]byte{expect}},
+		{[][]byte{expect[:1], expect[8:9]}},
+		{[][]byte{expect[:4], expect[8:12]}},
+		{[][]byte{expect[:4], expect[8:12]}},
+		{[][]byte{expect[:8], expect[8:16]}},
+		{[][]byte{expect[:128], expect[128:256]}},
+		{[][]byte{expect[:128], expect[128:]}},
+		{[][]byte{expect[:100], expect[104:]}},
+	}
 
-	if !bytes.Equal(expect, got) {
-		t.Errorf("got = %#x; want = %#x", got, expect)
+	var s State
+	for _, tt := range cases {
+		s.Init(seed)
+		for _, expect := range tt.expect {
+			got := make([]byte, len(expect))
+			s.FillRand(got)
+			if !bytes.Equal(expect, got) {
+				t.Errorf("got = %#x; want = %#x", got, expect)
+			}
+		}
 	}
 }
 

src/math/rand/v2/chacha8_test.go

@@ -531,8 +531,21 @@ var chacha8marshal = []string{
 	"chacha8:\x00\x00\x00\x00\x00\x00\x00{K3\x9bB!,\x94\x9d\x975\xce'O_t\xee|\xb21\x87\xbb\xbb\xfd)\x8f\xe52\x01\vP\fk",
 }
 
+func TestChaCha8Read(t *testing.T) {
+	c := NewChaCha8(chacha8seed)
+	n, err := c.Read(make([]byte, 128))
+	if n != 128 || err != nil {
+		t.Errorf("(*ChaCha8).Read(buf) = (%v, %v); want = (128, nil)", n, err)
+	}
+
+	n, err = c.Read(make([]byte, 0))
+	if n != 0 || err != nil {
+		t.Errorf("(*ChaCha8).Read(buf) = (%v, %v); want = (0, nil)", n, err)
+	}
+}
+
 func BenchmarkRead(b *testing.B) {
-	for _, v := range []int{1, 3, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 1024 * 2, 1024 * 16} {
+	for _, v := range []int{1, 2, 3, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 1024 * 2, 1024 * 16} {
 		b.Run(strconv.FormatInt(int64(v), 10), func(b *testing.B) {
 			r := NewChaCha8(chacha8seed)
 			buf := make([]byte, v)