walk: factor Listing helpers into their own file and add tests

fs/walk/helpers.go

@@ -0,0 +1,43 @@
+package walk
+
+import "github.com/rclone/rclone/fs"
+
+// Listing helpers used by backends
+
+// ListRHelper is used in the implementation of ListR to accumulate DirEntries
+type ListRHelper struct {
+	callback fs.ListRCallback
+	entries  fs.DirEntries
+}
+
+// NewListRHelper should be called from ListR with the callback passed in
+func NewListRHelper(callback fs.ListRCallback) *ListRHelper {
+	return &ListRHelper{
+		callback: callback,
+	}
+}
+
+// send sends the stored entries to the callback if there are >= max
+// entries.
+func (lh *ListRHelper) send(max int) (err error) {
+	if len(lh.entries) >= max {
+		err = lh.callback(lh.entries)
+		lh.entries = lh.entries[:0]
+	}
+	return err
+}
+
+// Add an entry to the stored entries and send them if there are more
+// than a certain amount
+func (lh *ListRHelper) Add(entry fs.DirEntry) error {
+	if entry == nil {
+		return nil
+	}
+	lh.entries = append(lh.entries, entry)
+	return lh.send(100)
+}
+
+// Flush the stored entries (if any) sending them to the callback
+func (lh *ListRHelper) Flush() error {
+	return lh.send(1)
+}

fs/walk/helpers_test.go

@@ -0,0 +1,90 @@
+package walk
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/rclone/rclone/fs"
+	"github.com/rclone/rclone/fstest/mockobject"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+// Mock callback to collect the entries
+func mockCallback(entries fs.DirEntries) error {
+	// Do nothing or log for testing purposes
+	return nil
+}
+
+func TestNewListRHelper(t *testing.T) {
+	callback := mockCallback
+	helper := NewListRHelper(callback)
+
+	assert.NotNil(t, helper)
+	assert.Equal(t, fmt.Sprintf("%p", callback), fmt.Sprintf("%p", helper.callback))
+	assert.Empty(t, helper.entries)
+}
+
+func TestListRHelperAdd(t *testing.T) {
+	callbackInvoked := false
+	callback := func(entries fs.DirEntries) error {
+		callbackInvoked = true
+		return nil
+	}
+
+	helper := NewListRHelper(callback)
+	entry := mockobject.Object("A")
+	require.NoError(t, helper.Add(entry))
+
+	assert.Len(t, helper.entries, 1)
+	assert.False(t, callbackInvoked, "Callback should not be invoked before reaching 100 entries")
+
+	// Check adding a nil entry doesn't change anything
+	require.NoError(t, helper.Add(nil))
+	assert.Len(t, helper.entries, 1)
+	assert.False(t, callbackInvoked, "Callback should not be invoked before reaching 100 entries")
+}
+
+func TestListRHelperSend(t *testing.T) {
+	entry := mockobject.Object("A")
+	callbackInvoked := false
+	callback := func(entries fs.DirEntries) error {
+		callbackInvoked = true
+		assert.Equal(t, 100, len(entries))
+		for _, obj := range entries {
+			assert.Equal(t, entry, obj)
+		}
+		return nil
+	}
+
+	helper := NewListRHelper(callback)
+
+	// Add 100 entries to force the callback to be invoked
+	for i := 0; i < 100; i++ {
+		require.NoError(t, helper.Add(entry))
+	}
+
+	assert.Len(t, helper.entries, 0)
+	assert.True(t, callbackInvoked, "Callback should be invoked after 100 entries")
+}
+
+func TestListRHelperFlush(t *testing.T) {
+	entry := mockobject.Object("A")
+	callbackInvoked := false
+	callback := func(entries fs.DirEntries) error {
+		callbackInvoked = true
+		assert.Equal(t, 1, len(entries))
+		for _, obj := range entries {
+			assert.Equal(t, entry, obj)
+		}
+		return nil
+	}
+
+	helper := NewListRHelper(callback)
+	require.NoError(t, helper.Add(entry))
+	assert.False(t, callbackInvoked, "Callback should not have been invoked yet")
+	require.NoError(t, helper.Flush())
+
+	assert.True(t, callbackInvoked, "Callback should be invoked on flush")
+	assert.Len(t, helper.entries, 0, "Entries should be cleared after flush")
+}

fs/walk/walk.go

@@ -641,41 +641,3 @@ func GetAll(ctx context.Context, f fs.Fs, path string, includeAll bool, maxLevel
 	})
 	return
 }
-
-// ListRHelper is used in the implementation of ListR to accumulate DirEntries
-type ListRHelper struct {
-	callback fs.ListRCallback
-	entries  fs.DirEntries
-}
-
-// NewListRHelper should be called from ListR with the callback passed in
-func NewListRHelper(callback fs.ListRCallback) *ListRHelper {
-	return &ListRHelper{
-		callback: callback,
-	}
-}
-
-// send sends the stored entries to the callback if there are >= max
-// entries.
-func (lh *ListRHelper) send(max int) (err error) {
-	if len(lh.entries) >= max {
-		err = lh.callback(lh.entries)
-		lh.entries = lh.entries[:0]
-	}
-	return err
-}
-
-// Add an entry to the stored entries and send them if there are more
-// than a certain amount
-func (lh *ListRHelper) Add(entry fs.DirEntry) error {
-	if entry == nil {
-		return nil
-	}
-	lh.entries = append(lh.entries, entry)
-	return lh.send(100)
-}
-
-// Flush the stored entries (if any) sending them to the callback
-func (lh *ListRHelper) Flush() error {
-	return lh.send(1)
-}