Delete sync snapshots file when destroying a bundle (#323)

## Changes
This PR changes the files.Delete() mutator to delete the sync snapshots
file on destroy. This ensures that files will be uploaded when the
bundle is uploaded again.

## Tests
- [x] Manual test: Ran `bricks bundle destroy`, observed that the sync
snapshots file was deleted.

bundle/deploy/files/delete.go

@@ -49,6 +49,16 @@ func (m *delete) Apply(ctx context.Context, b *bundle.Bundle) ([]bundle.Mutator,
 		return nil, err
 	}
 
+	// Clean up sync snapshot file
+	sync, err := getSync(ctx, b)
+	if err != nil {
+		return nil, err
+	}
+	err = sync.DestroySnapshot(ctx)
+	if err != nil {
+		return nil, err
+	}
+
 	fmt.Println("Successfully deleted files!")
 	return nil, nil
 }

bundle/deploy/files/sync.go

@@ -0,0 +1,26 @@
+package files
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/databricks/bricks/bundle"
+	"github.com/databricks/bricks/libs/sync"
+)
+
+func getSync(ctx context.Context, b *bundle.Bundle) (*sync.Sync, error) {
+	cacheDir, err := b.CacheDir()
+	if err != nil {
+		return nil, fmt.Errorf("cannot get bundle cache directory: %w", err)
+	}
+
+	opts := sync.SyncOptions{
+		LocalPath:  b.Config.Path,
+		RemotePath: b.Config.Workspace.FilePath.Workspace,
+		Full:       false,
+
+		SnapshotBasePath: cacheDir,
+		WorkspaceClient:  b.WorkspaceClient(),
+	}
+	return sync.New(ctx, opts)
+}

bundle/deploy/files/upload.go

@@ -2,10 +2,8 @@ package files
 
 import (
 	"context"
-	"fmt"
 
 	"github.com/databricks/bricks/bundle"
-	sync "github.com/databricks/bricks/libs/sync"
 )
 
 type upload struct{}
@@ -15,21 +13,7 @@ func (m *upload) Name() string {
 }
 
 func (m *upload) Apply(ctx context.Context, b *bundle.Bundle) ([]bundle.Mutator, error) {
-	cacheDir, err := b.CacheDir()
-	if err != nil {
-		return nil, fmt.Errorf("cannot get bundle cache directory: %w", err)
-	}
-
-	opts := sync.SyncOptions{
-		LocalPath:  b.Config.Path,
-		RemotePath: b.Config.Workspace.FilePath.Workspace,
-		Full:       false,
-
-		SnapshotBasePath: cacheDir,
-		WorkspaceClient:  b.WorkspaceClient(),
-	}
-
-	sync, err := sync.New(ctx, opts)
+	sync, err := getSync(ctx, b)
 	if err != nil {
 		return nil, err
 	}

libs/sync/snapshot.go

@@ -126,6 +126,14 @@ func (s *Snapshot) Save(ctx context.Context) error {
 	return nil
 }
 
+func (s *Snapshot) Destroy(ctx context.Context) error {
+	err := os.Remove(s.SnapshotPath)
+	if err != nil {
+		return fmt.Errorf("failed to destroy sync snapshot file: %s", err)
+	}
+	return nil
+}
+
 func loadOrNewSnapshot(ctx context.Context, opts *SyncOptions) (*Snapshot, error) {
 	snapshot, err := newSnapshot(ctx, opts)
 	if err != nil {

libs/sync/sync.go

@@ -160,6 +160,10 @@ func (s *Sync) RunOnce(ctx context.Context) error {
 	return nil
 }
 
+func (s *Sync) DestroySnapshot(ctx context.Context) error {
+	return s.snapshot.Destroy(ctx)
+}
+
 func (s *Sync) RunContinuous(ctx context.Context) error {
 	ticker := time.NewTicker(s.PollInterval)
 	defer ticker.Stop()