bufio: improve NewReaderSize, Peek, and UnreadByte test coverage
R=golang-codereviews, dave
CC=golang-codereviews
https://golang.org/cl/42990045
diff --git a/src/pkg/bufio/bufio_test.go b/src/pkg/bufio/bufio_test.go
index 41bd3d4..5cd0307 100644
--- a/src/pkg/bufio/bufio_test.go
+++ b/src/pkg/bufio/bufio_test.go
@@ -139,7 +139,7 @@
const minReadBufferSize = 16
var bufsizes = []int{
- minReadBufferSize, 23, 32, 46, 64, 93, 128, 1024, 4096,
+ 0, minReadBufferSize, 23, 32, 46, 64, 93, 128, 1024, 4096,
}
func TestReader(t *testing.T) {
@@ -259,6 +259,38 @@
}
}
+func TestUnreadByte(t *testing.T) {
+ want := "Hello, world"
+ got := ""
+ segments := []string{"Hello, ", "world"}
+ r := NewReader(&StringReader{data: segments})
+ // Normal execution.
+ for {
+ b1, err := r.ReadByte()
+ if err != nil {
+ if err != io.EOF {
+ t.Fatal("unexpected EOF")
+ }
+ break
+ }
+ got += string(b1)
+ // Put it back and read it again
+ if err = r.UnreadByte(); err != nil {
+ t.Fatalf("unexpected error on UnreadByte: %v", err)
+ }
+ b2, err := r.ReadByte()
+ if err != nil {
+ t.Fatalf("unexpected error reading after unreading: %v", err)
+ }
+ if b1 != b2 {
+ t.Fatalf("incorrect byte after unread: got %c wanted %c", b1, b2)
+ }
+ }
+ if got != want {
+ t.Errorf("got=%q want=%q", got, want)
+ }
+}
+
// Test that UnreadRune fails if the preceding operation was not a ReadRune.
func TestUnreadRuneError(t *testing.T) {
buf := make([]byte, 3) // All runes in this test are 3 bytes long
@@ -516,6 +548,9 @@
if s, err := buf.Peek(4); string(s) != "abcd" || err != nil {
t.Fatalf("want %q got %q, err=%v", "abcd", string(s), err)
}
+ if _, err := buf.Peek(-1); err != ErrNegativeCount {
+ t.Fatalf("want ErrNegativeCount got %v", err)
+ }
if _, err := buf.Peek(32); err != ErrBufferFull {
t.Fatalf("want ErrBufFull got %v", err)
}
