vfs: add tests and subsequent fixes

* Tests for VFS layer
  * Small fixes found during testing
  * Fix Close, Flush and Release behaviour for ReadFileHandle and WriteFileHandle
  * Fix nil object bugs on File

vfs/read_test.go

@@ -0,0 +1,238 @@
+package vfs
+
+import (
+	"io"
+	"os"
+	"testing"
+
+	"github.com/ncw/rclone/fstest"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+// Open a file for write
+func readHandleCreate(t *testing.T, r *fstest.Run) (*VFS, *ReadFileHandle) {
+	vfs := New(r.Fremote, nil)
+
+	file1 := r.WriteObject("dir/file1", "0123456789abcdef", t1)
+	fstest.CheckItems(t, r.Fremote, file1)
+
+	h, err := vfs.OpenFile("dir/file1", os.O_RDONLY, 0777)
+	require.NoError(t, err)
+	fh, ok := h.(*ReadFileHandle)
+	require.True(t, ok)
+
+	return vfs, fh
+}
+
+// read data from the string
+func readString(t *testing.T, fh *ReadFileHandle, n int) string {
+	buf := make([]byte, n)
+	n, err := fh.Read(buf)
+	if err != io.EOF {
+		assert.NoError(t, err)
+	}
+	return string(buf[:n])
+}
+
+func TestReadFileHandleMethods(t *testing.T) {
+	r := fstest.NewRun(t)
+	defer r.Finalise()
+	_, fh := readHandleCreate(t, r)
+
+	// String
+	assert.Equal(t, "dir/file1 (r)", fh.String())
+	assert.Equal(t, "<nil *ReadFileHandle>", (*ReadFileHandle)(nil).String())
+	assert.Equal(t, "<nil *ReadFileHandle.file>", new(ReadFileHandle).String())
+
+	// Node
+	node := fh.Node()
+	assert.Equal(t, "file1", node.Name())
+
+	// Size
+	assert.Equal(t, int64(16), fh.Size())
+
+	// Read 1
+	assert.Equal(t, "0", readString(t, fh, 1))
+
+	// Read remainder
+	assert.Equal(t, "123456789abcdef", readString(t, fh, 256))
+
+	// Read EOF
+	buf := make([]byte, 16)
+	_, err := fh.Read(buf)
+	assert.Equal(t, io.EOF, err)
+
+	// Stat
+	var fi os.FileInfo
+	fi, err = fh.Stat()
+	assert.NoError(t, err)
+	assert.Equal(t, int64(16), fi.Size())
+	assert.Equal(t, "file1", fi.Name())
+
+	// Close
+	assert.False(t, fh.closed)
+	assert.Equal(t, nil, fh.Close())
+	assert.True(t, fh.closed)
+
+	// Close again
+	assert.Equal(t, EBADF, fh.Close())
+}
+
+func TestReadFileHandleSeek(t *testing.T) {
+	r := fstest.NewRun(t)
+	defer r.Finalise()
+	_, fh := readHandleCreate(t, r)
+
+	assert.Equal(t, "0", readString(t, fh, 1))
+
+	// 0 means relative to the origin of the file,
+	n, err := fh.Seek(5, 0)
+	assert.NoError(t, err)
+	assert.Equal(t, int64(5), n)
+	assert.Equal(t, "5", readString(t, fh, 1))
+
+	// 1 means relative to the current offset
+	n, err = fh.Seek(-3, 1)
+	assert.NoError(t, err)
+	assert.Equal(t, int64(3), n)
+	assert.Equal(t, "3", readString(t, fh, 1))
+
+	// 2 means relative to the end.
+	n, err = fh.Seek(-3, 2)
+	assert.NoError(t, err)
+	assert.Equal(t, int64(13), n)
+	assert.Equal(t, "d", readString(t, fh, 1))
+
+	// Seek off the end
+	n, err = fh.Seek(100, 0)
+	assert.NoError(t, err)
+
+	// Get the error on read
+	buf := make([]byte, 16)
+	l, err := fh.Read(buf)
+	assert.Equal(t, io.EOF, err)
+	assert.Equal(t, 0, l)
+
+	// Check if noSeek is set we get an error
+	fh.noSeek = true
+	_, err = fh.Seek(0, 0)
+	assert.Equal(t, ESPIPE, err)
+
+	// Close
+	assert.Equal(t, nil, fh.Close())
+}
+
+func TestReadFileHandleReadAt(t *testing.T) {
+	r := fstest.NewRun(t)
+	defer r.Finalise()
+	_, fh := readHandleCreate(t, r)
+
+	// read from start
+	buf := make([]byte, 1)
+	n, err := fh.ReadAt(buf, 0)
+	require.NoError(t, err)
+	assert.Equal(t, 1, n)
+	assert.Equal(t, "0", string(buf[:n]))
+
+	// seek forwards
+	n, err = fh.ReadAt(buf, 5)
+	require.NoError(t, err)
+	assert.Equal(t, 1, n)
+	assert.Equal(t, "5", string(buf[:n]))
+
+	// seek backwards
+	n, err = fh.ReadAt(buf, 1)
+	require.NoError(t, err)
+	assert.Equal(t, 1, n)
+	assert.Equal(t, "1", string(buf[:n]))
+
+	// read exactly to the end
+	buf = make([]byte, 6)
+	n, err = fh.ReadAt(buf, 10)
+	require.NoError(t, err)
+	assert.Equal(t, 6, n)
+	assert.Equal(t, "abcdef", string(buf[:n]))
+
+	// read off the end
+	buf = make([]byte, 256)
+	n, err = fh.ReadAt(buf, 10)
+	assert.Equal(t, io.EOF, err)
+	assert.Equal(t, 6, n)
+	assert.Equal(t, "abcdef", string(buf[:n]))
+
+	// read starting off the end
+	n, err = fh.ReadAt(buf, 100)
+	assert.Equal(t, io.EOF, err)
+	assert.Equal(t, 0, n)
+
+	// check noSeek gives an error
+	fh.noSeek = true
+	n, err = fh.ReadAt(buf, 100)
+	assert.Equal(t, ESPIPE, err)
+
+	// Properly close the file
+	assert.NoError(t, fh.Close())
+
+	// check reading on closed file
+	fh.noSeek = true
+	n, err = fh.ReadAt(buf, 100)
+	assert.Equal(t, EBADF, err)
+}
+
+func TestReadFileHandleFlush(t *testing.T) {
+	r := fstest.NewRun(t)
+	defer r.Finalise()
+	_, fh := readHandleCreate(t, r)
+
+	// Check Flush does nothing if read not called
+	err := fh.Flush()
+	assert.NoError(t, err)
+	assert.False(t, fh.closed)
+
+	// Read data
+	buf := make([]byte, 256)
+	n, err := fh.Read(buf)
+	assert.Equal(t, io.EOF, err)
+	assert.Equal(t, 16, n)
+
+	// Check Flush does nothing if read called
+	err = fh.Flush()
+	assert.NoError(t, err)
+	assert.False(t, fh.closed)
+
+	// Check flush does nothing if called again
+	err = fh.Flush()
+	assert.NoError(t, err)
+	assert.False(t, fh.closed)
+
+	// Properly close the file
+	assert.NoError(t, fh.Close())
+}
+
+func TestReadFileHandleRelease(t *testing.T) {
+	r := fstest.NewRun(t)
+	defer r.Finalise()
+	_, fh := readHandleCreate(t, r)
+
+	// Check Release does nothing if file not read from
+	err := fh.Release()
+	assert.NoError(t, err)
+	assert.False(t, fh.closed)
+
+	// Read data
+	buf := make([]byte, 256)
+	n, err := fh.Read(buf)
+	assert.Equal(t, io.EOF, err)
+	assert.Equal(t, 16, n)
+
+	// Check Release closes file
+	err = fh.Release()
+	assert.NoError(t, err)
+	assert.True(t, fh.closed)
+
+	// Check Release does nothing if called again
+	err = fh.Release()
+	assert.NoError(t, err)
+	assert.True(t, fh.closed)
+}