Fix bug in diagnostics for UnconstrainedBox class. (#27381)

packages/flutter/lib/src/widgets/basic.dart

@@ -2068,8 +2068,8 @@ class UnconstrainedBox extends SingleChildRenderObjectWidget {
   void debugFillProperties(DiagnosticPropertiesBuilder properties) {
     super.debugFillProperties(properties);
     properties.add(DiagnosticsProperty<AlignmentGeometry>('alignment', alignment));
-    properties.add(DiagnosticsProperty<Axis>('constrainedAxis', null));
-    properties.add(DiagnosticsProperty<TextDirection>('textDirection', textDirection, defaultValue: null));
+    properties.add(EnumProperty<Axis>('constrainedAxis', constrainedAxis, defaultValue: null));
+    properties.add(EnumProperty<TextDirection>('textDirection', textDirection, defaultValue: null));
   }
 }
 

packages/flutter/test/widgets/basic_test.dart

@@ -145,6 +145,17 @@ void main() {
       expect(_pointerDown, isTrue);
     });
   });
+
+  test('UnconstrainedBox toString', () {
+    expect(
+      const UnconstrainedBox(constrainedAxis: Axis.vertical,).toString(),
+      equals('UnconstrainedBox(alignment: center, constrainedAxis: vertical)'),
+    );
+    expect(
+      const UnconstrainedBox(constrainedAxis: Axis.horizontal, textDirection: TextDirection.rtl, alignment: Alignment.topRight).toString(),
+      equals('UnconstrainedBox(alignment: topRight, constrainedAxis: horizontal, textDirection: rtl)'),
+    );
+  });
 }
 
 HitsRenderBox hits(RenderBox renderBox) => HitsRenderBox(renderBox);