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/write_test.go

@@ -0,0 +1,160 @@
+package vfs
+
+import (
+	"os"
+	"testing"
+
+	"github.com/ncw/rclone/fs"
+	"github.com/ncw/rclone/fstest"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+// Open a file for write
+func writeHandleCreate(t *testing.T, r *fstest.Run) (*VFS, *WriteFileHandle) {
+	vfs := New(r.Fremote, nil)
+
+	h, err := vfs.OpenFile("file1", os.O_WRONLY|os.O_CREATE, 0777)
+	require.NoError(t, err)
+	fh, ok := h.(*WriteFileHandle)
+	require.True(t, ok)
+
+	return vfs, fh
+}
+
+func TestWriteFileHandleMethods(t *testing.T) {
+	r := fstest.NewRun(t)
+	defer r.Finalise()
+	vfs, fh := writeHandleCreate(t, r)
+
+	// String
+	assert.Equal(t, "file1 (w)", fh.String())
+	assert.Equal(t, "<nil *WriteFileHandle>", (*WriteFileHandle)(nil).String())
+	assert.Equal(t, "<nil *WriteFileHandle.file>", new(WriteFileHandle).String())
+
+	// Node
+	node := fh.Node()
+	assert.Equal(t, "file1", node.Name())
+
+	// Offset #1
+	assert.Equal(t, int64(0), fh.Offset())
+	assert.Equal(t, int64(0), node.Size())
+
+	// Write (smoke test only since heavy lifting done in WriteAt)
+	n, err := fh.Write([]byte("hello"))
+	assert.NoError(t, err)
+	assert.Equal(t, 5, n)
+
+	// Offset #2
+	assert.Equal(t, int64(5), fh.Offset())
+	assert.Equal(t, int64(5), node.Size())
+
+	// Stat
+	var fi os.FileInfo
+	fi, err = fh.Stat()
+	assert.NoError(t, err)
+	assert.Equal(t, int64(5), fi.Size())
+	assert.Equal(t, "file1", fi.Name())
+
+	// Close
+	assert.NoError(t, fh.Close())
+
+	// Check double close
+	err = fh.Close()
+	assert.Equal(t, EBADF, err)
+
+	// check vfs
+	root, err := vfs.Root()
+	checkListing(t, root, []string{"file1,5,false"})
+
+	// check the underlying r.Fremote but not the modtime
+	file1 := fstest.NewItem("file1", "hello", t1)
+	fstest.CheckListingWithPrecision(t, r.Fremote, []fstest.Item{file1}, []string{}, fs.ModTimeNotSupported)
+}
+
+func TestWriteFileHandleWriteAt(t *testing.T) {
+	r := fstest.NewRun(t)
+	defer r.Finalise()
+	vfs, fh := writeHandleCreate(t, r)
+
+	// Preconditions
+	assert.Equal(t, int64(0), fh.offset)
+	assert.False(t, fh.writeCalled)
+
+	// Write the data
+	n, err := fh.WriteAt([]byte("hello"), 0)
+	assert.NoError(t, err)
+	assert.Equal(t, 5, n)
+
+	// After write
+	assert.Equal(t, int64(5), fh.offset)
+	assert.True(t, fh.writeCalled)
+
+	// Check can't seek
+	n, err = fh.WriteAt([]byte("hello"), 100)
+	assert.Equal(t, ESPIPE, err)
+	assert.Equal(t, 0, n)
+
+	// Write more data
+	n, err = fh.WriteAt([]byte(" world"), 5)
+	assert.NoError(t, err)
+	assert.Equal(t, 6, n)
+
+	// Close
+	assert.NoError(t, fh.Close())
+
+	// Check can't write on closed handle
+	n, err = fh.WriteAt([]byte("hello"), 0)
+	assert.Equal(t, EBADF, err)
+	assert.Equal(t, 0, n)
+
+	// check vfs
+	root, err := vfs.Root()
+	checkListing(t, root, []string{"file1,11,false"})
+
+	// check the underlying r.Fremote but not the modtime
+	file1 := fstest.NewItem("file1", "hello world", t1)
+	fstest.CheckListingWithPrecision(t, r.Fremote, []fstest.Item{file1}, []string{}, fs.ModTimeNotSupported)
+}
+
+func TestWriteFileHandleFlush(t *testing.T) {
+	r := fstest.NewRun(t)
+	defer r.Finalise()
+	_, fh := writeHandleCreate(t, r)
+
+	// Check Flush does nothing if write not called
+	err := fh.Flush()
+	assert.NoError(t, err)
+	assert.False(t, fh.closed)
+
+	// Write some data
+	n, err := fh.Write([]byte("hello"))
+	assert.NoError(t, err)
+	assert.Equal(t, 5, n)
+
+	// Check Flush closes file if write called
+	err = fh.Flush()
+	assert.NoError(t, err)
+	assert.True(t, fh.closed)
+
+	// Check flush does nothing if called again
+	err = fh.Flush()
+	assert.NoError(t, err)
+	assert.True(t, fh.closed)
+}
+
+func TestWriteFileHandleRelease(t *testing.T) {
+	r := fstest.NewRun(t)
+	defer r.Finalise()
+	_, fh := writeHandleCreate(t, r)
+
+	// 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)
+}