add deletion logic

pkg/executor/build.go

@@ -372,7 +372,8 @@ func (s *stageBuilder) build() error {
 		files = command.FilesToSnapshot()
 		timing.DefaultRun.Stop(t)
 
-		if !s.shouldTakeSnapshot(index, files, command.ProvidesFilesToSnapshot()) {
+		if !s.shouldTakeSnapshot(index, files, command.ProvidesFilesToSnapshot(),
+			command.ShouldDetectDeletedFiles()) {
 			continue
 		}
 		if isCacheCommand {
@@ -432,7 +433,7 @@ func (s *stageBuilder) takeSnapshot(files []string, shdDelete bool) (string, err
 	return snapshot, err
 }
 
-func (s *stageBuilder) shouldTakeSnapshot(index int, files []string, provideFiles bool) bool {
+func (s *stageBuilder) shouldTakeSnapshot(index int, files []string, provideFiles bool, detectDeletion bool) bool {
 	isLastCommand := index == len(s.cmds)-1
 
 	// We only snapshot the very end with single snapshot mode on.
@@ -450,6 +451,9 @@ func (s *stageBuilder) shouldTakeSnapshot(index int, files []string, provideFile
 		return true
 	}
 
+	if detectDeletion {
+		return true
+	}
 	// Don't snapshot an empty list.
 	if len(files) == 0 {
 		return false

pkg/executor/build_test.go

@@ -204,7 +204,7 @@ func Test_stageBuilder_shouldTakeSnapshot(t *testing.T) {
 				opts:  tt.fields.opts,
 				cmds:  tt.fields.cmds,
 			}
-			if got := s.shouldTakeSnapshot(tt.args.index, tt.args.files, tt.args.hasFiles); got != tt.want {
+			if got := s.shouldTakeSnapshot(tt.args.index, tt.args.files, tt.args.hasFiles, false); got != tt.want {
 				t.Errorf("stageBuilder.shouldTakeSnapshot() = %v, want %v", got, tt.want)
 			}
 		})

pkg/executor/fakes.go

@@ -38,7 +38,7 @@ func (f fakeSnapShotter) Init() error { return nil }
 func (f fakeSnapShotter) TakeSnapshotFS() (string, error) {
 	return f.tarPath, nil
 }
-func (f fakeSnapShotter) TakeSnapshot(_ []string) (string, error) {
+func (f fakeSnapShotter) TakeSnapshot(_ []string, _ bool) (string, error) {
 	return f.tarPath, nil
 }