bytes: additional test coverage

Add coverage for some uncovered bytes methods. The increase in actual coverage is disapointing small.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/13651044

src/pkg/bytes/bytes_test.go

@@ -143,6 +143,7 @@ var indexTests = []BinOpTest{
 	{"", "a", -1},
 	{"", "foo", -1},
 	{"fo", "foo", -1},
+	{"foo", "baz", -1},
 	{"foo", "foo", 0},
 	{"oofofoofooo", "f", 2},
 	{"oofofoofooo", "foo", 4},
@@ -1082,6 +1083,24 @@ func TestTitle(t *testing.T) {
 	}
 }
 
+var ToTitleTests = []TitleTest{
+	{"", ""},
+	{"a", "A"},
+	{" aaa aaa aaa ", " AAA AAA AAA "},
+	{" Aaa Aaa Aaa ", " AAA AAA AAA "},
+	{"123a456", "123A456"},
+	{"double-blind", "DOUBLE-BLIND"},
+	{"ÿøû", "ŸØÛ"},
+}
+
+func TestToTitle(t *testing.T) {
+	for _, tt := range ToTitleTests {
+		if s := string(ToTitle([]byte(tt.in))); s != tt.out {
+			t.Errorf("ToTitle(%q) = %q, want %q", tt.in, s, tt.out)
+		}
+	}
+}
+
 var EqualFoldTests = []struct {
 	s, t string
 	out  bool
@@ -1110,6 +1129,37 @@ func TestEqualFold(t *testing.T) {
 	}
 }
 
+func TestBufferGrowNegative(t *testing.T) {
+	defer func() {
+		if err := recover(); err == nil {
+			t.Fatal("Grow(-1) should have paniced")
+		}
+	}()
+	var b Buffer
+	b.Grow(-1)
+}
+
+func TestBufferTruncateNegative(t *testing.T) {
+	defer func() {
+		if err := recover(); err == nil {
+			t.Fatal("Truncate(-1) should have paniced")
+		}
+	}()
+	var b Buffer
+	b.Truncate(-1)
+}
+
+func TestBufferTruncateOutOfRange(t *testing.T) {
+	defer func() {
+		if err := recover(); err == nil {
+			t.Fatal("Truncate(20) should have paniced")
+		}
+	}()
+	var b Buffer
+	b.Write(make([]byte, 10))
+	b.Truncate(20)
+}
+
 var makeFieldsInput = func() []byte {
 	x := make([]byte, 1<<20)
 	// Input is ~10% space, ~10% 2-byte UTF-8, rest ASCII non-space.

src/pkg/bytes/reader_test.go

@@ -113,6 +113,41 @@ func TestReaderWriteTo(t *testing.T) {
 	}
 }
 
+func TestReaderLen(t *testing.T) {
+	const data = "hello world"
+	r := NewReader([]byte(data))
+	if got, want := r.Len(), 11; got != want {
+		t.Errorf("r.Len(): got %d, want %d", got, want)
+	}
+	if n, err := r.Read(make([]byte, 10)); err != nil || n != 10 {
+		t.Errorf("Read failed: read %d %v", n, err)
+	}
+	if got, want := r.Len(), 1; got != want {
+		t.Errorf("r.Len(): got %d, want %d", got, want)
+	}
+	if n, err := r.Read(make([]byte, 1)); err != nil || n != 1 {
+		t.Errorf("Read failed: read %d %v", n, err)
+	}
+	if got, want := r.Len(), 0; got != want {
+		t.Errorf("r.Len(): got %d, want %d", got, want)
+	}
+}
+
+func TestReaderDoubleUnreadRune(t *testing.T) {
+	buf := NewBuffer([]byte("groucho"))
+	if _, _, err := buf.ReadRune(); err != nil {
+		// should not happen
+		t.Fatal(err)
+	}
+	if err := buf.UnreadByte(); err != nil {
+		// should not happen
+		t.Fatal(err)
+	}
+	if err := buf.UnreadByte(); err == nil {
+		t.Fatal("UnreadByte: expected error, got nil")
+	}
+}
+
 // verify that copying from an empty reader always has the same results,
 // regardless of the presence of a WriteTo method.
 func TestReaderCopyNothing(t *testing.T) {