[#641] ir/container: Add unique attributes check

Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>

pkg/core/container/fmt.go

@@ -9,7 +9,11 @@ import (
 	"github.com/nspcc-dev/neofs-api-go/pkg/owner"
 )
 
-var errNilPolicy = errors.New("placement policy is nil")
+var (
+	errNilPolicy          = errors.New("placement policy is nil")
+	errRepeatedAttributes = errors.New("repeated attributes found")
+	errEmptyAttribute     = errors.New("empty attribute found")
+)
 
 // CheckFormat conducts an initial check of the v2 container data.
 //
@@ -32,5 +36,20 @@ func CheckFormat(c *container.Container) error {
 		return fmt.Errorf("incorrect nonce: %w", err)
 	}
 
+	// check if there are repeated attributes
+	attrs := c.Attributes()
+	uniqueAttr := make(map[string]struct{}, len(attrs))
+	for _, attr := range attrs {
+		if _, exists := uniqueAttr[attr.Key()]; exists {
+			return errRepeatedAttributes
+		}
+
+		if attr.Value() == "" {
+			return errEmptyAttribute
+		}
+
+		uniqueAttr[attr.Key()] = struct{}{}
+	}
+
 	return nil
 }

pkg/core/container/fmt_test.go

@@ -41,4 +41,30 @@ func TestCheckFormat(t *testing.T) {
 	c.SetNonceUUID(uuid.New())
 
 	require.NoError(t, CheckFormat(c))
+
+	// set empty value attribute
+	attr1 := container.NewAttribute()
+	attr1.SetKey("attr")
+	attrs := container.Attributes{attr1}
+
+	c.SetAttributes(attrs)
+
+	require.ErrorIs(t, CheckFormat(c), errEmptyAttribute)
+
+	// add same key attribute
+	attr2 := container.NewAttribute()
+	attr2.SetKey(attr1.Key())
+	attr2.SetValue("val")
+
+	attr1.SetValue(attr2.Value())
+
+	attrs = append(attrs, attr2)
+
+	c.SetAttributes(attrs)
+
+	require.ErrorIs(t, CheckFormat(c), errRepeatedAttributes)
+
+	attr2.SetKey(attr1.Key() + "smth")
+
+	require.NoError(t, CheckFormat(c))
 }