wear/protolayout/protolayout-renderer/src/test/java/androidx/wear/protolayout/renderer/common/ProtoLayoutDifferTest.java - platform/frameworks/support - Git at Google

 /*
  * Copyright 2023 The Android Open Source Project
  *
  * 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 androidx.wear.protolayout.renderer.common;

 import static androidx.wear.protolayout.renderer.helper.TestDsl.arc;
 import static androidx.wear.protolayout.renderer.helper.TestDsl.arcText;
 import static androidx.wear.protolayout.renderer.helper.TestDsl.column;
 import static androidx.wear.protolayout.renderer.helper.TestDsl.layout;
 import static androidx.wear.protolayout.renderer.helper.TestDsl.row;
 import static androidx.wear.protolayout.renderer.helper.TestDsl.spanText;
 import static androidx.wear.protolayout.renderer.helper.TestDsl.spannable;
 import static androidx.wear.protolayout.renderer.helper.TestDsl.text;

 import static com.google.common.truth.Truth.assertThat;

 import androidx.test.ext.junit.runners.AndroidJUnit4;
 import androidx.wear.protolayout.proto.LayoutElementProto.ArcLayoutElement;
 import androidx.wear.protolayout.proto.LayoutElementProto.Layout;
 import androidx.wear.protolayout.proto.LayoutElementProto.LayoutElement;
 import androidx.wear.protolayout.proto.LayoutElementProto.Span;
 import androidx.wear.protolayout.renderer.common.ProtoLayoutDiffer.LayoutDiff;
 import androidx.wear.protolayout.renderer.common.ProtoLayoutDiffer.TreeNodeWithChange;

 import org.junit.Test;
 import org.junit.runner.RunWith;

 @RunWith(AndroidJUnit4.class)
 public class ProtoLayoutDifferTest {
  @Test
  public void createNodePosId_withSameParams() {
  String posId1 = ProtoLayoutDiffer.createNodePosId("parent", 1);
  String posId2 = ProtoLayoutDiffer.createNodePosId("parent", 1);
  assertThat(posId1).isNotEmpty();
  assertThat(posId2).isNotEmpty();
  assertThat(posId1).isEqualTo(posId2);
  }

  @Test
  public void createNodePosId_withDifferentParams() {
  String posId1 = ProtoLayoutDiffer.createNodePosId("parent", 1);
  String posId2 = ProtoLayoutDiffer.createNodePosId("parent", 2);
  String posId3 = ProtoLayoutDiffer.createNodePosId("foo", 2);
  assertThat(posId1).isNotEmpty();
  assertThat(posId2).isNotEmpty();
  assertThat(posId1).isNotEqualTo(posId2);
  assertThat(posId2).isNotEqualTo(posId3);
  }

  @Test
  public void getParentNodePosId_withValidValue() {
  String grandParentNodePosId = ProtoLayoutDiffer.ROOT_NODE_ID;
  String parentNodePosId = ProtoLayoutDiffer.createNodePosId(grandParentNodePosId, 1);
  String nodePosId = ProtoLayoutDiffer.createNodePosId(parentNodePosId, 3);

  assertThat(ProtoLayoutDiffer.getParentNodePosId(nodePosId)).isEqualTo(parentNodePosId);
  assertThat(ProtoLayoutDiffer.getParentNodePosId(parentNodePosId))
  .isEqualTo(grandParentNodePosId);
  }

  @Test
  public void getParentNodePosId_withInvalidValues() {
  assertThat(ProtoLayoutDiffer.getParentNodePosId(ProtoLayoutDiffer.ROOT_NODE_ID)).isNull();
  assertThat(ProtoLayoutDiffer.getParentNodePosId("not_a_pos_id")).isNull();
  }

  @Test
  public void getChangedNodes_withNoChange() {
  LayoutDiff diff =
  ProtoLayoutDiffer.getDiff(referenceLayout().getFingerprint(), referenceLayout());
  assertThat(diff).isNotNull();
  assertThat(diff.getChangedNodes()).isEmpty();
  }

  @Test
  public void getChangedNodes_forLayoutWithNoFingerprint() {
  LayoutDiff diff =
  ProtoLayoutDiffer.getDiff(
  referenceLayout().getFingerprint(),
  referenceLayout().toBuilder().clearFingerprint().build());
  assertThat(diff).isNull();
  }

  @Test
  public void getChangedNodes_withOneUpdatedNode() {
  LayoutDiff diff =
  ProtoLayoutDiffer.getDiff(
  referenceLayout().getFingerprint(), layoutWithOneUpdatedNode());
  assertThat(diff).isNotNull();
  assertThat(diff.getChangedNodes()).hasSize(1);
  TreeNodeWithChange changedNode = diff.getChangedNodes().get(0);
  assertThat(changedNode.getLayoutElement()).isNotNull();
  assertThat(changedNode.getPosId()).isEqualTo("pT1.1.2");
  assertThat(textValue(changedNode.getLayoutElement())).isEqualTo("UPDATED");
  assertThat(changedNode.isSelfOnlyChange()).isTrue();
  }

  @Test
  public void getChangedNodes_withOneUpdatedParentAndOneUpdatedChild() {
  LayoutDiff diff =
  ProtoLayoutDiffer.getDiff(
  referenceLayout().getFingerprint(),
  layoutWithOneUpdatedParentAndOneUpdatedChild());
  assertThat(diff).isNotNull();
  assertThat(diff.getChangedNodes()).hasSize(2);

  TreeNodeWithChange changedParentNode = diff.getChangedNodes().get(0);
  assertThat(changedParentNode.getLayoutElement()).isNotNull();
  assertThat(changedParentNode.getPosId()).isEqualTo("pT1.1");
  assertThat(changedParentNode.isSelfOnlyChange()).isTrue();

  TreeNodeWithChange changedChildNode = diff.getChangedNodes().get(1);
  assertThat(changedChildNode.getLayoutElement()).isNotNull();
  assertThat(changedChildNode.getPosId()).isEqualTo("pT1.1.2");
  assertThat(textValue(changedChildNode.getLayoutElement())).isEqualTo("UPDATED");
  assertThat(changedChildNode.isSelfOnlyChange()).isTrue();
  }

  @Test
  public void getChangedNodes_withTwoUpdatedNodes() {
  LayoutDiff diff =
  ProtoLayoutDiffer.getDiff(
  referenceLayout().getFingerprint(), layoutWithTwoUpdatedNodes());
  assertThat(diff).isNotNull();
  assertThat(diff.getChangedNodes()).hasSize(2);
  TreeNodeWithChange changedNode1 = diff.getChangedNodes().get(0);
  assertThat(changedNode1.getLayoutElement()).isNotNull();
  assertThat(changedNode1.getPosId()).isEqualTo("pT1.1.1");
  assertThat(textValue(changedNode1.getLayoutElement())).isEqualTo("UPDATED1");
  assertThat(changedNode1.isSelfOnlyChange()).isTrue();
  TreeNodeWithChange changedNode2 = diff.getChangedNodes().get(1);
  assertThat(changedNode2.getLayoutElement()).isNotNull();
  assertThat(textValue(changedNode2.getLayoutElement())).isEqualTo("UPDATED2");
  assertThat(changedNode2.isSelfOnlyChange()).isTrue();
  }

  @Test
  public void getChangedNodes_withDifferentNumberOfChildren() {
  LayoutDiff diff =
  ProtoLayoutDiffer.getDiff(
  referenceLayout().getFingerprint(), layoutWithDifferentNumberOfChildren());
  assertThat(diff).isNotNull();
  assertThat(diff.getChangedNodes()).hasSize(1);
  TreeNodeWithChange changedNode = diff.getChangedNodes().get(0);
  assertThat(changedNode.getPosId()).isEqualTo("pT1.1");
  assertThat(changedNode.getLayoutElement()).isNotNull();
  assertThat(changedNode.getLayoutElement().hasRow()).isTrue();
  assertThat(changedNode.isSelfOnlyChange()).isFalse();
  }

  @Test
  public void getChangedNodes_withChangeInArc() {
  LayoutDiff diff =
  ProtoLayoutDiffer.getDiff(
  referenceLayout().getFingerprint(), layoutWithChangeInArc());
  assertThat(diff).isNotNull();
  assertThat(diff.getChangedNodes()).hasSize(1);
  TreeNodeWithChange changedNode = diff.getChangedNodes().get(0);
  assertThat(changedNode.getPosId()).isEqualTo("pT1.4.1");
  assertThat(changedNode.getArcLayoutElement()).isNotNull();
  assertThat(textValue(changedNode.getArcLayoutElement())).isEqualTo("UPDATED");
  assertThat(changedNode.isSelfOnlyChange()).isTrue();
  }

  @Test
  public void getChangedNodes_withChangeInSpannable() {
  Layout layout1 = layout(spannable(spanText("Hello"), spanText("World")));
  Layout layout2 = layout(spannable(spanText("Hello"), spanText("Mars")));
  LayoutDiff diff = ProtoLayoutDiffer.getDiff(layout1.getFingerprint(), layout2);
  assertThat(diff).isNotNull();
  assertThat(diff.getChangedNodes()).hasSize(1);
  TreeNodeWithChange changedNode = diff.getChangedNodes().get(0);
  // Although the change is in one of the Spans, we consider the Spannable itself to have
  // changed.
  assertThat(changedNode.getPosId()).isEqualTo("pT1");
  assertThat(changedNode.getLayoutElement()).isNotNull();
  assertThat(changedNode.getLayoutElement().hasSpannable()).isTrue();
  assertThat(textValue(changedNode.getLayoutElement().getSpannable().getSpans(1)))
  .isEqualTo("Mars");
  assertThat(changedNode.isSelfOnlyChange()).isTrue();
  }

  @Test
  public void getChangedNodes_withUpdateToNodeSelfFingerprint() {
  LayoutDiff diff =
  ProtoLayoutDiffer.getDiff(
  referenceLayout().getFingerprint(),
  layoutWithUpdateToNodeSelfFingerprint());
  assertThat(diff).isNotNull();
  assertThat(diff.getChangedNodes()).hasSize(1);
  TreeNodeWithChange changedNode = diff.getChangedNodes().get(0);
  assertThat(changedNode.getPosId()).isEqualTo("pT1.2");
  assertThat(changedNode.getLayoutElement()).isNotNull();
  assertThat(changedNode.getLayoutElement().hasRow()).isTrue();
  assertThat(changedNode.isSelfOnlyChange()).isTrue();
  }

  @Test
  public void areSameFingerprints() {
  assertThat(
  ProtoLayoutDiffer.areSameFingerprints(
  referenceLayout().getFingerprint(),
  referenceLayout().getFingerprint()))
  .isTrue();
  assertThat(
  ProtoLayoutDiffer.areSameFingerprints(
  referenceLayout().getFingerprint(),
  layoutWithOneUpdatedNode().getFingerprint()))
  .isFalse();
  assertThat(
  ProtoLayoutDiffer.areSameFingerprints(
  referenceLayout().getFingerprint(),
  layoutWithDifferentNumberOfChildren().getFingerprint()))
  .isFalse();
  assertThat(
  ProtoLayoutDiffer.areSameFingerprints(
  referenceLayout().getFingerprint(),
  layoutWithUpdateToNodeSelfFingerprint().getFingerprint()))
  .isFalse();
  }

  @Test
  public void isChildOf_forAnActualChild_returnsTrue() {
  String childPosId = "pT1.2.3";
  String parentPosId = "pT1.2";
  assertThat(ProtoLayoutDiffer.isDescendantOf(childPosId, parentPosId)).isTrue();
  }

  @Test
  public void isChildOf_forANonChild_returnsFalse() {
  String childPosId = "pT1.22.3";
  String parentPosId = "pT1.2";
  assertThat(ProtoLayoutDiffer.isDescendantOf(childPosId, parentPosId)).isFalse();
  }

  private static Layout referenceLayout() {
  return layout(
  column( // 1
  row( // 1.1
  text("Foo"), // 1.1.1
  text("Bar") // 1.1.2
  ),
  row( // 1.2
  text("Baz") // 1.2.1
  ),
  text("blah blah"), // 1.3
  arc( // 1.4
  arcText("arctext") // 1.4.1
  )));
  }

  private static Layout layoutWithOneUpdatedNode() {
  return layout(
  column( // 1
  row( // 1.1
  text("Foo"), // 1.1.1
  text("UPDATED") // 1.1.2
  ),
  row( // 1.2
  text("Baz") // 1.2.1
  ),
  text("blah blah"), // 1.3
  arc( // 1.4
  arcText("arctext") // 1.4.1
  )));
  }

  private static Layout layoutWithOneUpdatedParentAndOneUpdatedChild() {
  return layout(
  column( // 1
  row( // 1.1
  modifiers -> modifiers.widthDp = 123,
  text("Foo"), // 1.1.1
  text("UPDATED") // 1.1.2
  ),
  row( // 1.2
  text("Baz") // 1.2.1
  ),
  text("blah blah"), // 1.3
  arc( // 1.4
  arcText("arctext") // 1.4.1
  )));
  }

  private static Layout layoutWithTwoUpdatedNodes() {
  return layout(
  column( // 1
  row( // 1.1
  text("UPDATED1"), // 1.1.1
  text("Bar") // 1.1.2
  ),
  row( // 1.2
  text("Baz") // 1.2.1
  ),
  text("UPDATED2"), // 1.3
  arc( // 1.4
  arcText("arctext") // 1.4.1
  )));
  }

  private static Layout layoutWithDifferentNumberOfChildren() {
  return layout(
  column( // 1
  row( // 1.1
  text("Foo"), // 1.1.1
  text("Bar"), // 1.1.2
  text("EXTRA") // 1.1.3
  ),
  row( // 1.2
  text("Baz") // 1.2.1
  ),
  text("blah blah"), // 1.3
  arc( // 1.4
  arcText("arctext") // 1.4.1
  )));
  }

  private static Layout layoutWithChangeInArc() {
  return layout(
  column( // 1
  row( // 1.1
  text("Foo"), // 1.1.1
  text("Bar") // 1.1.2
  ),
  row( // 1.2
  text("Baz") // 1.2.1
  ),
  text("blah blah"), // 1.3
  arc( // 1.4
  arcText("UPDATED") // 1.4.1
  )));
  }

  private static Layout layoutWithUpdateToNodeSelfFingerprint() {
  return layout(
  column( // 1
  row( // 1.1
  text("Foo"), // 1.1.1
  text("Bar") // 1.1.2
  ),
  row( // 1.2
  props -> {
  props.modifiers.border.widthDp = 5;
  },
  text("Baz") // 1.2.1
  ),
  text("blah blah"), // 1.3
  arc(arcText("arctext")) // 1.4
  ));
  }

  private static String textValue(LayoutElement element) {
  return element.getText().getText().getValue();
  }

  private static String textValue(ArcLayoutElement element) {
  return element.getText().getText().getValue();
  }

  private static String textValue(Span element) {
  return element.getText().getText().getValue();
  }
 }
	/*
	* Copyright 2023 The Android Open Source Project
	*
	* 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 androidx.wear.protolayout.renderer.common;

	import static androidx.wear.protolayout.renderer.helper.TestDsl.arc;
	import static androidx.wear.protolayout.renderer.helper.TestDsl.arcText;
	import static androidx.wear.protolayout.renderer.helper.TestDsl.column;
	import static androidx.wear.protolayout.renderer.helper.TestDsl.layout;
	import static androidx.wear.protolayout.renderer.helper.TestDsl.row;
	import static androidx.wear.protolayout.renderer.helper.TestDsl.spanText;
	import static androidx.wear.protolayout.renderer.helper.TestDsl.spannable;
	import static androidx.wear.protolayout.renderer.helper.TestDsl.text;

	import static com.google.common.truth.Truth.assertThat;

	import androidx.test.ext.junit.runners.AndroidJUnit4;
	import androidx.wear.protolayout.proto.LayoutElementProto.ArcLayoutElement;
	import androidx.wear.protolayout.proto.LayoutElementProto.Layout;
	import androidx.wear.protolayout.proto.LayoutElementProto.LayoutElement;
	import androidx.wear.protolayout.proto.LayoutElementProto.Span;
	import androidx.wear.protolayout.renderer.common.ProtoLayoutDiffer.LayoutDiff;
	import androidx.wear.protolayout.renderer.common.ProtoLayoutDiffer.TreeNodeWithChange;

	import org.junit.Test;
	import org.junit.runner.RunWith;

	@RunWith(AndroidJUnit4.class)
	public class ProtoLayoutDifferTest {
	@Test
	public void createNodePosId_withSameParams() {
	String posId1 = ProtoLayoutDiffer.createNodePosId("parent", 1);
	String posId2 = ProtoLayoutDiffer.createNodePosId("parent", 1);
	assertThat(posId1).isNotEmpty();
	assertThat(posId2).isNotEmpty();
	assertThat(posId1).isEqualTo(posId2);
	}

	@Test
	public void createNodePosId_withDifferentParams() {
	String posId1 = ProtoLayoutDiffer.createNodePosId("parent", 1);
	String posId2 = ProtoLayoutDiffer.createNodePosId("parent", 2);
	String posId3 = ProtoLayoutDiffer.createNodePosId("foo", 2);
	assertThat(posId1).isNotEmpty();
	assertThat(posId2).isNotEmpty();
	assertThat(posId1).isNotEqualTo(posId2);
	assertThat(posId2).isNotEqualTo(posId3);
	}

	@Test
	public void getParentNodePosId_withValidValue() {
	String grandParentNodePosId = ProtoLayoutDiffer.ROOT_NODE_ID;
	String parentNodePosId = ProtoLayoutDiffer.createNodePosId(grandParentNodePosId, 1);
	String nodePosId = ProtoLayoutDiffer.createNodePosId(parentNodePosId, 3);

	assertThat(ProtoLayoutDiffer.getParentNodePosId(nodePosId)).isEqualTo(parentNodePosId);
	assertThat(ProtoLayoutDiffer.getParentNodePosId(parentNodePosId))
	.isEqualTo(grandParentNodePosId);
	}

	@Test
	public void getParentNodePosId_withInvalidValues() {
	assertThat(ProtoLayoutDiffer.getParentNodePosId(ProtoLayoutDiffer.ROOT_NODE_ID)).isNull();
	assertThat(ProtoLayoutDiffer.getParentNodePosId("not_a_pos_id")).isNull();
	}

	@Test
	public void getChangedNodes_withNoChange() {
	LayoutDiff diff =
	ProtoLayoutDiffer.getDiff(referenceLayout().getFingerprint(), referenceLayout());
	assertThat(diff).isNotNull();
	assertThat(diff.getChangedNodes()).isEmpty();
	}

	@Test
	public void getChangedNodes_forLayoutWithNoFingerprint() {
	LayoutDiff diff =
	ProtoLayoutDiffer.getDiff(
	referenceLayout().getFingerprint(),
	referenceLayout().toBuilder().clearFingerprint().build());
	assertThat(diff).isNull();
	}

	@Test
	public void getChangedNodes_withOneUpdatedNode() {
	LayoutDiff diff =
	ProtoLayoutDiffer.getDiff(
	referenceLayout().getFingerprint(), layoutWithOneUpdatedNode());
	assertThat(diff).isNotNull();
	assertThat(diff.getChangedNodes()).hasSize(1);
	TreeNodeWithChange changedNode = diff.getChangedNodes().get(0);
	assertThat(changedNode.getLayoutElement()).isNotNull();
	assertThat(changedNode.getPosId()).isEqualTo("pT1.1.2");
	assertThat(textValue(changedNode.getLayoutElement())).isEqualTo("UPDATED");
	assertThat(changedNode.isSelfOnlyChange()).isTrue();
	}

	@Test
	public void getChangedNodes_withOneUpdatedParentAndOneUpdatedChild() {
	LayoutDiff diff =
	ProtoLayoutDiffer.getDiff(
	referenceLayout().getFingerprint(),
	layoutWithOneUpdatedParentAndOneUpdatedChild());
	assertThat(diff).isNotNull();
	assertThat(diff.getChangedNodes()).hasSize(2);

	TreeNodeWithChange changedParentNode = diff.getChangedNodes().get(0);
	assertThat(changedParentNode.getLayoutElement()).isNotNull();
	assertThat(changedParentNode.getPosId()).isEqualTo("pT1.1");
	assertThat(changedParentNode.isSelfOnlyChange()).isTrue();

	TreeNodeWithChange changedChildNode = diff.getChangedNodes().get(1);
	assertThat(changedChildNode.getLayoutElement()).isNotNull();
	assertThat(changedChildNode.getPosId()).isEqualTo("pT1.1.2");
	assertThat(textValue(changedChildNode.getLayoutElement())).isEqualTo("UPDATED");
	assertThat(changedChildNode.isSelfOnlyChange()).isTrue();
	}

	@Test
	public void getChangedNodes_withTwoUpdatedNodes() {
	LayoutDiff diff =
	ProtoLayoutDiffer.getDiff(
	referenceLayout().getFingerprint(), layoutWithTwoUpdatedNodes());
	assertThat(diff).isNotNull();
	assertThat(diff.getChangedNodes()).hasSize(2);
	TreeNodeWithChange changedNode1 = diff.getChangedNodes().get(0);
	assertThat(changedNode1.getLayoutElement()).isNotNull();
	assertThat(changedNode1.getPosId()).isEqualTo("pT1.1.1");
	assertThat(textValue(changedNode1.getLayoutElement())).isEqualTo("UPDATED1");
	assertThat(changedNode1.isSelfOnlyChange()).isTrue();
	TreeNodeWithChange changedNode2 = diff.getChangedNodes().get(1);
	assertThat(changedNode2.getLayoutElement()).isNotNull();
	assertThat(textValue(changedNode2.getLayoutElement())).isEqualTo("UPDATED2");
	assertThat(changedNode2.isSelfOnlyChange()).isTrue();
	}

	@Test
	public void getChangedNodes_withDifferentNumberOfChildren() {
	LayoutDiff diff =
	ProtoLayoutDiffer.getDiff(
	referenceLayout().getFingerprint(), layoutWithDifferentNumberOfChildren());
	assertThat(diff).isNotNull();
	assertThat(diff.getChangedNodes()).hasSize(1);
	TreeNodeWithChange changedNode = diff.getChangedNodes().get(0);
	assertThat(changedNode.getPosId()).isEqualTo("pT1.1");
	assertThat(changedNode.getLayoutElement()).isNotNull();
	assertThat(changedNode.getLayoutElement().hasRow()).isTrue();
	assertThat(changedNode.isSelfOnlyChange()).isFalse();
	}

	@Test
	public void getChangedNodes_withChangeInArc() {
	LayoutDiff diff =
	ProtoLayoutDiffer.getDiff(
	referenceLayout().getFingerprint(), layoutWithChangeInArc());
	assertThat(diff).isNotNull();
	assertThat(diff.getChangedNodes()).hasSize(1);
	TreeNodeWithChange changedNode = diff.getChangedNodes().get(0);
	assertThat(changedNode.getPosId()).isEqualTo("pT1.4.1");
	assertThat(changedNode.getArcLayoutElement()).isNotNull();
	assertThat(textValue(changedNode.getArcLayoutElement())).isEqualTo("UPDATED");
	assertThat(changedNode.isSelfOnlyChange()).isTrue();
	}

	@Test
	public void getChangedNodes_withChangeInSpannable() {
	Layout layout1 = layout(spannable(spanText("Hello"), spanText("World")));
	Layout layout2 = layout(spannable(spanText("Hello"), spanText("Mars")));
	LayoutDiff diff = ProtoLayoutDiffer.getDiff(layout1.getFingerprint(), layout2);
	assertThat(diff).isNotNull();
	assertThat(diff.getChangedNodes()).hasSize(1);
	TreeNodeWithChange changedNode = diff.getChangedNodes().get(0);
	// Although the change is in one of the Spans, we consider the Spannable itself to have
	// changed.
	assertThat(changedNode.getPosId()).isEqualTo("pT1");
	assertThat(changedNode.getLayoutElement()).isNotNull();
	assertThat(changedNode.getLayoutElement().hasSpannable()).isTrue();
	assertThat(textValue(changedNode.getLayoutElement().getSpannable().getSpans(1)))
	.isEqualTo("Mars");
	assertThat(changedNode.isSelfOnlyChange()).isTrue();
	}

	@Test
	public void getChangedNodes_withUpdateToNodeSelfFingerprint() {
	LayoutDiff diff =
	ProtoLayoutDiffer.getDiff(
	referenceLayout().getFingerprint(),
	layoutWithUpdateToNodeSelfFingerprint());
	assertThat(diff).isNotNull();
	assertThat(diff.getChangedNodes()).hasSize(1);
	TreeNodeWithChange changedNode = diff.getChangedNodes().get(0);
	assertThat(changedNode.getPosId()).isEqualTo("pT1.2");
	assertThat(changedNode.getLayoutElement()).isNotNull();
	assertThat(changedNode.getLayoutElement().hasRow()).isTrue();
	assertThat(changedNode.isSelfOnlyChange()).isTrue();
	}

	@Test
	public void areSameFingerprints() {
	assertThat(
	ProtoLayoutDiffer.areSameFingerprints(
	referenceLayout().getFingerprint(),
	referenceLayout().getFingerprint()))
	.isTrue();
	assertThat(
	ProtoLayoutDiffer.areSameFingerprints(
	referenceLayout().getFingerprint(),
	layoutWithOneUpdatedNode().getFingerprint()))
	.isFalse();
	assertThat(
	ProtoLayoutDiffer.areSameFingerprints(
	referenceLayout().getFingerprint(),
	layoutWithDifferentNumberOfChildren().getFingerprint()))
	.isFalse();
	assertThat(
	ProtoLayoutDiffer.areSameFingerprints(
	referenceLayout().getFingerprint(),
	layoutWithUpdateToNodeSelfFingerprint().getFingerprint()))
	.isFalse();
	}

	@Test
	public void isChildOf_forAnActualChild_returnsTrue() {
	String childPosId = "pT1.2.3";
	String parentPosId = "pT1.2";
	assertThat(ProtoLayoutDiffer.isDescendantOf(childPosId, parentPosId)).isTrue();
	}

	@Test
	public void isChildOf_forANonChild_returnsFalse() {
	String childPosId = "pT1.22.3";
	String parentPosId = "pT1.2";
	assertThat(ProtoLayoutDiffer.isDescendantOf(childPosId, parentPosId)).isFalse();
	}

	private static Layout referenceLayout() {
	return layout(
	column( // 1
	row( // 1.1
	text("Foo"), // 1.1.1
	text("Bar") // 1.1.2
	),
	row( // 1.2
	text("Baz") // 1.2.1
	),
	text("blah blah"), // 1.3
	arc( // 1.4
	arcText("arctext") // 1.4.1
	)));
	}

	private static Layout layoutWithOneUpdatedNode() {
	return layout(
	column( // 1
	row( // 1.1
	text("Foo"), // 1.1.1
	text("UPDATED") // 1.1.2
	),
	row( // 1.2
	text("Baz") // 1.2.1
	),
	text("blah blah"), // 1.3
	arc( // 1.4
	arcText("arctext") // 1.4.1
	)));
	}

	private static Layout layoutWithOneUpdatedParentAndOneUpdatedChild() {
	return layout(
	column( // 1
	row( // 1.1
	modifiers -> modifiers.widthDp = 123,
	text("Foo"), // 1.1.1
	text("UPDATED") // 1.1.2
	),
	row( // 1.2
	text("Baz") // 1.2.1
	),
	text("blah blah"), // 1.3
	arc( // 1.4
	arcText("arctext") // 1.4.1
	)));
	}

	private static Layout layoutWithTwoUpdatedNodes() {
	return layout(
	column( // 1
	row( // 1.1
	text("UPDATED1"), // 1.1.1
	text("Bar") // 1.1.2
	),
	row( // 1.2
	text("Baz") // 1.2.1
	),
	text("UPDATED2"), // 1.3
	arc( // 1.4
	arcText("arctext") // 1.4.1
	)));
	}

	private static Layout layoutWithDifferentNumberOfChildren() {
	return layout(
	column( // 1
	row( // 1.1
	text("Foo"), // 1.1.1
	text("Bar"), // 1.1.2
	text("EXTRA") // 1.1.3
	),
	row( // 1.2
	text("Baz") // 1.2.1
	),
	text("blah blah"), // 1.3
	arc( // 1.4
	arcText("arctext") // 1.4.1
	)));
	}

	private static Layout layoutWithChangeInArc() {
	return layout(
	column( // 1
	row( // 1.1
	text("Foo"), // 1.1.1
	text("Bar") // 1.1.2
	),
	row( // 1.2
	text("Baz") // 1.2.1
	),
	text("blah blah"), // 1.3
	arc( // 1.4
	arcText("UPDATED") // 1.4.1
	)));
	}

	private static Layout layoutWithUpdateToNodeSelfFingerprint() {
	return layout(
	column( // 1
	row( // 1.1
	text("Foo"), // 1.1.1
	text("Bar") // 1.1.2
	),
	row( // 1.2
	props -> {
	props.modifiers.border.widthDp = 5;
	},
	text("Baz") // 1.2.1
	),
	text("blah blah"), // 1.3
	arc(arcText("arctext")) // 1.4
	));
	}

	private static String textValue(LayoutElement element) {
	return element.getText().getText().getValue();
	}

	private static String textValue(ArcLayoutElement element) {
	return element.getText().getText().getValue();
	}

	private static String textValue(Span element) {
	return element.getText().getText().getValue();
	}
	}