feat: polish & windviz & deploy

internal/datasets/store_test.go

@@ -1,11 +1,64 @@
 package datasets
 
 import (
+	"context"
 	"os"
 	"testing"
 	"time"
 )
 
+func TestLocalStoreLockSerializes(t *testing.T) {
+	dir := t.TempDir()
+	store, _ := NewLocalStore(dir, "gfs-test")
+	ctx := context.Background()
+
+	release, err := store.Lock(ctx)
+	if err != nil {
+		t.Fatalf("first Lock: %v", err)
+	}
+
+	// A second acquisition must block until the first releases.
+	got := make(chan struct{})
+	go func() {
+		r2, err := store.Lock(ctx)
+		if err == nil {
+			r2()
+		}
+		close(got)
+	}()
+
+	select {
+	case <-got:
+		t.Fatal("second Lock acquired while first was held")
+	case <-time.After(100 * time.Millisecond):
+		// expected: still blocked
+	}
+	release()
+	select {
+	case <-got:
+		// expected: acquired after release
+	case <-time.After(2 * time.Second):
+		t.Fatal("second Lock did not acquire after release")
+	}
+}
+
+func TestLocalStoreLockContextCancel(t *testing.T) {
+	dir := t.TempDir()
+	store, _ := NewLocalStore(dir, "gfs-test")
+
+	release, err := store.Lock(context.Background())
+	if err != nil {
+		t.Fatalf("Lock: %v", err)
+	}
+	defer release()
+
+	ctx, cancel := context.WithCancel(context.Background())
+	cancel()
+	if _, err := store.Lock(ctx); err == nil {
+		t.Error("expected Lock to fail on cancelled context while held elsewhere")
+	}
+}
+
 func TestLocalStoreBeginWriteResume(t *testing.T) {
 	dir := t.TempDir()
 	store, err := NewLocalStore(dir, "gfs-test")