1 files changed, 32 insertions, 0 deletions

diff --git a/cli/internal/runcache/output_watcher.go b/cli/internal/runcache/output_watcher.go
new file mode 100644
index 0000000..5f90f0e
--- /dev/null
+++ b/cli/internal/runcache/output_watcher.go
@@ -0,0 +1,32 @@
+package runcache
+
+import (
+	"context"
+
+	"github.com/vercel/turbo/cli/internal/fs"
+)
+
+// OutputWatcher instances are responsible for tracking changes to task outputs
+type OutputWatcher interface {
+	// GetChangedOutputs returns which of the given globs have changed since the specified hash was last run
+	GetChangedOutputs(ctx context.Context, hash string, repoRelativeOutputGlobs []string) ([]string, error)
+	// NotifyOutputsWritten tells the watcher that the given globs have been cached with the specified hash
+	NotifyOutputsWritten(ctx context.Context, hash string, repoRelativeOutputGlobs fs.TaskOutputs) error
+}
+
+// NoOpOutputWatcher implements OutputWatcher, but always considers every glob to have changed
+type NoOpOutputWatcher struct{}
+
+var _ OutputWatcher = (*NoOpOutputWatcher)(nil)
+
+// GetChangedOutputs implements OutputWatcher.GetChangedOutputs.
+// Since this is a no-op watcher, no tracking is done.
+func (NoOpOutputWatcher) GetChangedOutputs(ctx context.Context, hash string, repoRelativeOutputGlobs []string) ([]string, error) {
+	return repoRelativeOutputGlobs, nil
+}
+
+// NotifyOutputsWritten implements OutputWatcher.NotifyOutputsWritten.
+// Since this is a no-op watcher, consider all globs to have changed
+func (NoOpOutputWatcher) NotifyOutputsWritten(ctx context.Context, hash string, repoRelativeOutputGlobs fs.TaskOutputs) error {
+	return nil
+}