From 6c13cd2735c04d9f58f95380a14707810348290c Mon Sep 17 00:00:00 2001 From: Paul Campbell Date: Thu, 26 May 2016 12:57:56 +0100 Subject: [PATCH] Node.getParent(): returns any parent inside an Optional Root nodes will return an empty Optional. --- src/main/java/net/kemitix/node/Node.java | 7 +-- src/main/java/net/kemitix/node/NodeItem.java | 11 +++-- .../java/net/kemitix/node/NodeItemTest.java | 46 +++++++++---------- 3 files changed, 33 insertions(+), 31 deletions(-) diff --git a/src/main/java/net/kemitix/node/Node.java b/src/main/java/net/kemitix/node/Node.java index f6e2de1..7cda730 100644 --- a/src/main/java/net/kemitix/node/Node.java +++ b/src/main/java/net/kemitix/node/Node.java @@ -53,13 +53,10 @@ public interface Node { /** * Fetch the parent node. - *

- * If the node is a root node, i.e. has no parent, then this will return - * null. * - * @return the parent node + * @return an Optional contain the parent node, or empty if a root node */ - Node getParent(); + Optional> getParent(); /** * Make the current node a direct child of the parent. diff --git a/src/main/java/net/kemitix/node/NodeItem.java b/src/main/java/net/kemitix/node/NodeItem.java index 956678c..ec71f11 100644 --- a/src/main/java/net/kemitix/node/NodeItem.java +++ b/src/main/java/net/kemitix/node/NodeItem.java @@ -139,8 +139,8 @@ public class NodeItem implements Node { } @Override - public Node getParent() { - return parent; + public Optional> getParent() { + return Optional.ofNullable(parent); } @Override @@ -170,7 +170,12 @@ public class NodeItem implements Node { } } children.add(child); - if (child.getParent() == null || !child.getParent().equals(this)) { + // update the child's parent if they don't have one or it is not this + Optional> childParent = child.getParent(); + boolean isOrphan = !childParent.isPresent(); + boolean hasDifferentParent = !isOrphan && !childParent.get() + .equals(this); + if (isOrphan || hasDifferentParent) { child.setParent(this); } } diff --git a/src/test/java/net/kemitix/node/NodeItemTest.java b/src/test/java/net/kemitix/node/NodeItemTest.java index c1a690a..68770a2 100644 --- a/src/test/java/net/kemitix/node/NodeItemTest.java +++ b/src/test/java/net/kemitix/node/NodeItemTest.java @@ -79,7 +79,7 @@ public class NodeItemTest { node = new NodeItem<>("data"); //then assertThat(node.getParent()).as( - "node created without a parent has null as parent").isNull(); + "node created without a parent has no parent").isEmpty(); } /** @@ -94,7 +94,7 @@ public class NodeItemTest { //then assertThat(node.getParent()).as( "node created with a parent can return the parent") - .isSameAs(parent); + .contains(parent); } /** @@ -142,7 +142,7 @@ public class NodeItemTest { //then assertThat(node.getParent()).as( "when a node is assigned a new parent that parent can be " - + "returned").isSameAs(parent); + + "returned").contains(parent); } /** @@ -187,7 +187,7 @@ public class NodeItemTest { //then assertThat(child.getParent()).as( "when a node is assigned a new parent, the old parent is " - + "replaced").isSameAs(newParent); + + "replaced").contains(newParent); assertThat(node.findChild("child").isPresent()).as( "when a node is assigned a new parent, the old parent no " + "longer has the node among it's children").isFalse(); @@ -209,7 +209,7 @@ public class NodeItemTest { assertThat(child.getParent()).as( "when a node with an existing parent is added as a child " + "to another node, then the old parent is replaced") - .isSameAs(newParent); + .contains(newParent); assertThat(node.findChild("child").isPresent()).as( "when a node with an existing parent is added as a child to " + "another node, then the old parent no longer has " @@ -309,14 +309,14 @@ public class NodeItemTest { @Test public void shouldSetParentOnChildWhenAddedAsChild() { //given - val child = new NodeItem("child"); node = new NodeItem<>("subject"); + val child = new NodeItem("child"); //when node.addChild(child); //then assertThat(child.getParent()).as( "when a node is added as a child, the child has the node as " - + "its parent").isSameAs(node); + + "its parent").contains(node); } /** @@ -411,7 +411,7 @@ public class NodeItemTest { val alpha = alphaOptional.get(); assertThat(alpha.getParent()).as( "when creating a descendant line, the first element has " - + "the current node as its parent").isSameAs(node); + + "the current node as its parent").contains(node); val betaOptional = alpha.findChild(betaData); assertThat(betaOptional.isPresent()).as( "when creating a descendant line, the second element is " @@ -421,7 +421,7 @@ public class NodeItemTest { assertThat(beta.getParent()).as( "when creating a descendant line, the second element " + "has the first as its parent") - .isSameAs(alpha); + .contains(alpha); val gammaOptional = beta.findChild(gammaData); assertThat(gammaOptional.isPresent()).as( "when creating a descendant line, the third element " @@ -431,7 +431,7 @@ public class NodeItemTest { assertThat(gamma.getParent()).as( "when creating a descendant line, the third " + "element has the second as its parent") - .isSameAs(beta); + .contains(beta); } } } @@ -561,7 +561,7 @@ public class NodeItemTest { //then assertThat(child.getParent()).as( "when creating a child node, the child has the current node " - + "as its parent").isSameAs(node); + + "as its parent").contains(node); val foundChild = node.findChild(childData); assertThat(foundChild.isPresent()).as( "when creating a child node, the child can be found by its " @@ -698,14 +698,14 @@ public class NodeItemTest { //when node.insertInPath(four, "one", "two", "three"); //then - val three = four.getParent(); + val three = four.getParent().get(); assertThat(four.getParent()).as("add node to a tree").isNotNull(); assertThat(three.getName()).isEqualTo("three"); - val two = three.getParent(); + val two = three.getParent().get(); assertThat(two.getName()).isEqualTo("two"); - val one = two.getParent(); + val one = two.getParent().get(); assertThat(one.getName()).isEqualTo("one"); - assertThat(one.getParent()).isSameAs(node); + assertThat(one.getParent().get()).isSameAs(node); assertThat(node.getChildByName("one") .getChildByName("two") .getChildByName("three") @@ -764,7 +764,7 @@ public class NodeItemTest { //when child.removeParent(); //then - assertThat(child.getParent()).isNull(); + assertThat(child.getParent()).isEmpty(); } @Test @@ -805,7 +805,7 @@ public class NodeItemTest { node.addChild(child); child.addChild(target); final NodeItem addMe = new NodeItem<>("I'm new", "target"); - assertThat(addMe.getParent()).isNull(); + assertThat(addMe.getParent()).isEmpty(); assertThat(child.getChildByName("target").isEmpty()).as( "target starts empty").isTrue(); //when @@ -920,7 +920,7 @@ public class NodeItemTest { Node child = node.createChild("child data", "child name"); //then assertThat(child.getName()).isEqualTo("child name"); - assertThat(child.getParent()).isSameAs(node); + assertThat(child.getParent()).contains(node); assertThat(node.getChildren()).containsExactly(child); } @@ -953,7 +953,7 @@ public class NodeItemTest { //when NodeItem child = new NodeItem<>(null, node); //then - assertThat(child.getParent()).isSameAs(node); + assertThat(child.getParent()).contains(node); assertThat(node.getChildren()).containsExactly(child); } @@ -1024,11 +1024,11 @@ public class NodeItemTest { public void canUseNameSupplierToBuildFullPath() { //given final Function, String> pathNameSupplier = node -> { - Node parent = node.getParent(); - if (parent == null) { - return ""; + Optional> parent = node.getParent(); + if (parent.isPresent()) { + return parent.get().getName() + "/" + node.getData().get(); } - return parent.getName() + "/" + node.getData().get(); + return ""; }; node = new NodeItem<>(null, pathNameSupplier); val child = new NodeItem("child", node);