Snapshot test for RedwoodView (#2331)

* Snapshot test for RedwoodView

Closes: #1859

* Actually exercise the interesting bit from the bug report

* Track rebase

redwood-widget-shared-test/build.gradle

@@ -0,0 +1,31 @@
+import static app.cash.redwood.buildsupport.TargetGroup.ToolkitAllWithoutAndroid
+
+redwoodBuild {
+  targets(ToolkitAllWithoutAndroid)
+}
+
+kotlin {
+  sourceSets {
+    commonMain {
+      dependencies {
+        api projects.redwoodLayoutApi
+        api projects.redwoodLayoutModifiers
+        api projects.redwoodLayoutWidget
+        api projects.redwoodRuntime
+        api projects.redwoodSnapshotTesting
+        api projects.redwoodTesting
+        api projects.redwoodWidget
+        api projects.redwoodYoga
+        api libs.kotlin.test
+      }
+    }
+    jvmMain {
+      dependencies {
+        // The kotlin.test library provides JVM variants for multiple testing frameworks. When used
+        // as a test dependency this selection is transparent. But since we are publishing a library
+        // we need to select one ourselves at compilation time.
+        api libs.kotlin.test.junit
+      }
+    }
+  }
+}

redwood-widget-shared-test/src/commonMain/kotlin/app/cash/redwood/widget/AbstractRedwoodViewTest.kt

@@ -0,0 +1,41 @@
+/*
+ * Copyright (C) 2024 Square, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package app.cash.redwood.widget
+
+import app.cash.redwood.snapshot.testing.Snapshotter
+import app.cash.redwood.snapshot.testing.TestWidgetFactory
+import app.cash.redwood.snapshot.testing.text
+import kotlin.test.Test
+
+abstract class AbstractRedwoodViewTest<W : Any, R : RedwoodView<W>> {
+
+  abstract val widgetFactory: TestWidgetFactory<W>
+
+  abstract fun redwoodView(): R
+
+  abstract fun snapshotter(redwoodView: R): Snapshotter
+
+  /**
+   * This test uses a string that wraps to confirm the root view's dimensions aren't unbounded.
+   * https://github.com/cashapp/redwood/issues/2128
+   */
+  @Test
+  fun testSingleChildElement() {
+    val redwoodView = redwoodView()
+    redwoodView.children.insert(0, widgetFactory.text("Hello ".repeat(50)))
+    snapshotter(redwoodView).snapshot()
+  }
+}