IMG-23: split imagetype (#1484)

* Image type (new)

* bufreader, RegisterFormat updated

* Remove StemExt

* Unknown = 0

* Joined imagedetect and imagetype

* Use regular []byte in bufreader

bufreader/bufreader_test.go

@@ -0,0 +1,97 @@
+package bufreader
+
+import (
+	"io"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/suite"
+)
+
+// BufferedReaderTestSuite defines the test suite for the buffered reader
+type BufferedReaderTestSuite struct {
+	suite.Suite
+}
+
+func (s *BufferedReaderTestSuite) TestRead() {
+	data := "hello world"
+	br := New(strings.NewReader(data))
+
+	// First read
+	p1 := make([]byte, 5)
+	n1, err1 := br.Read(p1)
+	s.Require().NoError(err1)
+	s.Equal(5, n1)
+	s.Equal("hello", string(p1))
+
+	// Second read
+	p2 := make([]byte, 6)
+	n2, err2 := br.Read(p2)
+	s.Require().NoError(err2)
+	s.Equal(6, n2)
+	s.Equal(" world", string(p2))
+
+	// Verify position
+	s.Equal(11, br.pos)
+}
+
+func (s *BufferedReaderTestSuite) TestEOF() {
+	data := "hello"
+	br := New(strings.NewReader(data))
+
+	// Read all data
+	p1 := make([]byte, 5)
+	n1, err1 := br.Read(p1)
+	s.Require().NoError(err1)
+	s.Equal(5, n1)
+	s.Equal("hello", string(p1))
+
+	// Try to read more - should get EOF
+	p2 := make([]byte, 5)
+	n2, err2 := br.Read(p2)
+	s.Equal(io.EOF, err2)
+	s.Equal(0, n2)
+}
+
+func (s *BufferedReaderTestSuite) TestEOF_WhenDataExhausted() {
+	data := "hello"
+	br := New(strings.NewReader(data))
+
+	// Try to read more than available
+	p := make([]byte, 10)
+	n, err := br.Read(p)
+
+	s.Require().NoError(err)
+	s.Equal(5, n)
+	s.Equal("hello", string(p[:n]))
+}
+
+func (s *BufferedReaderTestSuite) TestPeek() {
+	data := "hello world"
+	br := New(strings.NewReader(data))
+
+	// Peek at first 5 bytes
+	peeked, err := br.Peek(5)
+	s.Require().NoError(err)
+	s.Equal("hello", string(peeked))
+	s.Equal(0, br.pos) // Position should not change
+
+	// Read the same data to verify peek didn't consume it
+	p := make([]byte, 5)
+	n, err := br.Read(p)
+	s.Require().NoError(err)
+	s.Equal(5, n)
+	s.Equal("hello", string(p))
+	s.Equal(5, br.pos) // Position should now be updated
+
+	// Peek at the next 7 bytes (which are beyond the EOF)
+	peeked2, err := br.Peek(7)
+	s.Require().NoError(err)
+	s.Equal(" world", string(peeked2))
+	s.Equal(5, br.pos) // Position should still be 5
+}
+
+// TestBufferedReaderSuite runs the test suite
+func TestBufferedReader(t *testing.T) {
+	suite.Run(t, new(BufferedReaderTestSuite))
+}