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package utfbom
import (
"errors"
"io"
"reflect"
"testing"
"testing/iotest"
"time"
)
var testCases = []struct {
name string
input []byte
inputError error
encoding Encoding
output []byte
}{
{"1", []byte{}, nil, Unknown, []byte{}},
{"2", []byte("hello"), nil, Unknown, []byte("hello")},
{"3", []byte("\xEF\xBB\xBF"), nil, UTF8, []byte{}},
{"4", []byte("\xEF\xBB\xBFhello"), nil, UTF8, []byte("hello")},
{"5", []byte("\xFE\xFF"), nil, UTF16BigEndian, []byte{}},
{"6", []byte("\xFF\xFE"), nil, UTF16LittleEndian, []byte{}},
{"7", []byte("\x00\x00\xFE\xFF"), nil, UTF32BigEndian, []byte{}},
{"8", []byte("\xFF\xFE\x00\x00"), nil, UTF32LittleEndian, []byte{}},
{"5", []byte("\xFE\xFF\x00\x68\x00\x65\x00\x6C\x00\x6C\x00\x6F"), nil,
UTF16BigEndian, []byte{0x00, 0x68, 0x00, 0x65, 0x00, 0x6C, 0x00, 0x6C, 0x00, 0x6F}},
{"6", []byte("\xFF\xFE\x68\x00\x65\x00\x6C\x00\x6C\x00\x6F\x00"), nil,
UTF16LittleEndian, []byte{0x68, 0x00, 0x65, 0x00, 0x6C, 0x00, 0x6C, 0x00, 0x6F, 0x00}},
{"7", []byte("\x00\x00\xFE\xFF\x00\x00\x00\x68\x00\x00\x00\x65\x00\x00\x00\x6C\x00\x00\x00\x6C\x00\x00\x00\x6F"), nil,
UTF32BigEndian,
[]byte{0x00, 0x00, 0x00, 0x68, 0x00, 0x00, 0x00, 0x65, 0x00, 0x00, 0x00, 0x6C, 0x00, 0x00, 0x00, 0x6C, 0x00, 0x00, 0x00, 0x6F}},
{"8", []byte("\xFF\xFE\x00\x00\x68\x00\x00\x00\x65\x00\x00\x00\x6C\x00\x00\x00\x6C\x00\x00\x00\x6F\x00\x00\x00"), nil,
UTF32LittleEndian,
[]byte{0x68, 0x00, 0x00, 0x00, 0x65, 0x00, 0x00, 0x00, 0x6C, 0x00, 0x00, 0x00, 0x6C, 0x00, 0x00, 0x00, 0x6F, 0x00, 0x00, 0x00}},
{"9", []byte("\xEF"), nil, Unknown, []byte("\xEF")},
{"10", []byte("\xEF\xBB"), nil, Unknown, []byte("\xEF\xBB")},
{"11", []byte("\xEF\xBB\xBF"), io.ErrClosedPipe, UTF8, []byte{}},
{"12", []byte("\xFE\xFF"), io.ErrClosedPipe, Unknown, []byte("\xFE\xFF")},
{"13", []byte("\xFE"), io.ErrClosedPipe, Unknown, []byte("\xFE")},
{"14", []byte("\xFF\xFE"), io.ErrClosedPipe, Unknown, []byte("\xFF\xFE")},
{"15", []byte("\x00\x00\xFE\xFF"), io.ErrClosedPipe, UTF32BigEndian, []byte{}},
{"16", []byte("\x00\x00\xFE"), io.ErrClosedPipe, Unknown, []byte{0x00, 0x00, 0xFE}},
{"17", []byte("\x00\x00"), io.ErrClosedPipe, Unknown, []byte{0x00, 0x00}},
{"18", []byte("\x00"), io.ErrClosedPipe, Unknown, []byte{0x00}},
{"19", []byte("\xFF\xFE\x00\x00"), io.ErrClosedPipe, UTF32LittleEndian, []byte{}},
{"20", []byte("\xFF\xFE\x00"), io.ErrClosedPipe, Unknown, []byte{0xFF, 0xFE, 0x00}},
{"21", []byte("\xFF\xFE"), io.ErrClosedPipe, Unknown, []byte{0xFF, 0xFE}},
{"22", []byte("\xFF"), io.ErrClosedPipe, Unknown, []byte{0xFF}},
{"23", []byte("\x68\x65"), nil, Unknown, []byte{0x68, 0x65}},
}
type sliceReader struct {
input []byte
inputError error
}
func (r *sliceReader) Read(p []byte) (n int, err error) {
if len(p) == 0 {
return
}
if err = r.getError(); err != nil {
return
}
n = copy(p, r.input)
r.input = r.input[n:]
err = r.getError()
return
}
func (r *sliceReader) getError() (err error) {
if len(r.input) == 0 {
if r.inputError == nil {
err = io.EOF
} else {
err = r.inputError
}
}
return
}
var readMakers = []struct {
name string
fn func(io.Reader) io.Reader
}{
{"full", func(r io.Reader) io.Reader { return r }},
{"byte", iotest.OneByteReader},
}
func TestSkip(t *testing.T) {
for _, tc := range testCases {
for _, readMaker := range readMakers {
r := readMaker.fn(&sliceReader{tc.input, tc.inputError})
sr, enc := Skip(r)
if enc != tc.encoding {
t.Fatalf("test %v reader=%s: expected encoding %v, but got %v", tc.name, readMaker.name, tc.encoding, enc)
}
output, err := io.ReadAll(sr)
if !reflect.DeepEqual(output, tc.output) {
t.Fatalf("test %v reader=%s: expected to read %+#v, but got %+#v", tc.name, readMaker.name, tc.output, output)
}
if !errors.Is(err, tc.inputError) {
t.Fatalf("test %v reader=%s: expected to get %+#v error, but got %+#v", tc.name, readMaker.name, tc.inputError, err)
}
}
}
}
func TestSkipSkip(t *testing.T) {
for _, tc := range testCases {
for _, readMaker := range readMakers {
r := readMaker.fn(&sliceReader{tc.input, tc.inputError})
sr0, _ := Skip(r)
sr, enc := Skip(sr0)
if enc != Unknown {
t.Fatalf("test %v reader=%s: expected encoding %v, but got %v", tc.name, readMaker.name, Unknown, enc)
}
output, err := io.ReadAll(sr)
if !reflect.DeepEqual(output, tc.output) {
t.Fatalf("test %v reader=%s: expected to read %+#v, but got %+#v", tc.name, readMaker.name, tc.output, output)
}
if !errors.Is(err, tc.inputError) {
t.Fatalf("test %v reader=%s: expected to get %+#v error, but got %+#v", tc.name, readMaker.name, tc.inputError, err)
}
}
}
}
func TestSkipOnly(t *testing.T) {
for _, tc := range testCases {
for _, readMaker := range readMakers {
r := readMaker.fn(&sliceReader{tc.input, tc.inputError})
sr := SkipOnly(r)
output, err := io.ReadAll(sr)
if !reflect.DeepEqual(output, tc.output) {
t.Fatalf("test %v reader=%s: expected to read %+#v, but got %+#v", tc.name, readMaker.name, tc.output, output)
}
if !errors.Is(err, tc.inputError) {
t.Fatalf("test %v reader=%s: expected to get %+#v error, but got %+#v", tc.name, readMaker.name, tc.inputError, err)
}
}
}
}
type zeroReader struct{}
func (zeroReader) Read(p []byte) (int, error) {
return 0, nil
}
type readerEncoding struct {
Rd *Reader
Enc Encoding
}
func TestSkipZeroReader(t *testing.T) {
var z zeroReader
c := make(chan readerEncoding)
go func() {
r, enc := Skip(z)
c <- readerEncoding{r, enc}
}()
select {
case re := <-c:
if re.Enc != Unknown {
t.Error("Unknown encoding expected")
} else {
var b [1]byte
n, err := re.Rd.Read(b[:])
if n != 0 {
t.Error("unexpected bytes count:", n)
}
if !errors.Is(err, io.ErrNoProgress) {
t.Error("unexpected error:", err)
}
}
case <-time.After(time.Second):
t.Error("test timed out (endless loop in Skip?)")
}
}
func TestSkipOnlyZeroReader(t *testing.T) {
var z zeroReader
c := make(chan *Reader)
go func() {
r := SkipOnly(z)
c <- r
}()
select {
case r := <-c:
var b [1]byte
n, err := r.Read(b[:])
if n != 0 {
t.Error("unexpected bytes count:", n)
}
if !errors.Is(err, io.ErrNoProgress) {
t.Error("unexpected error:", err)
}
case <-time.After(time.Second):
t.Error("test timed out (endless loop in Skip?)")
}
}
func TestReader_ReadEmpty(t *testing.T) {
for _, tc := range testCases {
for _, readMaker := range readMakers {
r := readMaker.fn(&sliceReader{tc.input, tc.inputError})
sr := SkipOnly(r)
n, err := sr.Read(nil)
if n != 0 {
t.Fatalf("test %v reader=%s: expected to read zero bytes, but got %v", tc.name, readMaker.name, n)
}
if err != nil {
t.Fatalf("test %v reader=%s: expected to get <nil> error, but got %+#v", tc.name, readMaker.name, err)
}
}
}
}
func TestEncoding_String(t *testing.T) {
for e := Unknown; e <= UTF32LittleEndian; e++ {
s := e.String()
if s == "" {
t.Errorf("no string for %#v", e)
}
}
s := Encoding(999).String()
if s != "Unknown" {
t.Errorf("wrong string '%s' for invalid encoding", s)
}
}
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