Apply Defaults explicitly

redwood-layout-composeui/src/androidUnitTest/kotlin/app/cash/redwood/layout/composeui/ComposeUiBoxTest.kt

@@ -41,6 +41,7 @@ class ComposeUiBoxTest(
   override val widgetFactory = ComposeUiTestWidgetFactory
 
   override fun box(): Box<@Composable () -> Unit> = ComposeUiBox(0x88000000.toInt())
+    .apply { applyDefaults() }
 
   override fun snapshotter(widget: @Composable () -> Unit) = ComposeSnapshotter(paparazzi, widget)
 }

redwood-layout-shared-test/src/commonMain/kotlin/app/cash/redwood/layout/AbstractBoxTest.kt

@@ -36,6 +36,18 @@ abstract class AbstractBoxTest<T : Any> {
 
   abstract fun box(): Box<T>
 
+  /**
+   * Explicitly apply defaults to our Box instance. This is only necessary in tests; in production
+   * the framework explicitly sets every property.
+   */
+  protected fun Box<T>.applyDefaults() {
+    width(Constraint.Wrap)
+    height(Constraint.Wrap)
+    margin(Margin.Zero)
+    horizontalAlignment(CrossAxisAlignment.Start)
+    verticalAlignment(CrossAxisAlignment.Start)
+  }
+
   abstract fun snapshotter(widget: T): Snapshotter
 
   @Test

redwood-layout-uiview/src/commonTest/kotlin/app/cash/redwood/layout/uiview/UIViewBoxTest.kt

@@ -36,6 +36,7 @@ class UIViewBoxTest(
   override fun box(): Box<UIView> {
     return UIViewBox().apply {
       value.backgroundColor = UIColor(red = 0.0, green = 0.0, blue = 0.0, alpha = 0.5)
+      applyDefaults()
     }
   }
 

redwood-layout-view/src/test/kotlin/app/cash/redwood/layout/view/ViewBoxTest.kt

@@ -47,6 +47,7 @@ class ViewBoxTest(
   override fun box(): Box<View> {
     return ViewBox(paparazzi.context).apply {
       background = ColorDrawable(0x88000000.toInt())
+      applyDefaults()
     }
   }