Clean up Node interface (#60)

* NoteItem Remove @NonNull from private method parameters

* When creating node with null children treat as no children

* NodeItem use Lombok Getter/Setter

* Extract NodeTreeDraw

* Remove getData()

* Remove getChild()

* Remove getParent()

* Remove getChildByName()

* Merge NodeTreeDraw into Nodes

* Remove methodcound suppression

* [changelog] Updated

CHANGELOG.org

@@ -9,16 +9,29 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ** Added
 
-- Add kemitix-maven-tiles
+- Add kemitix-maven-tiles 2.4.1
 
 ** Changed
 
 - Replace Jenkins with Github Actions (#57)
 - [checkstyle] suppress npath complexity issues
 - [coverage] lower requirements
+- Clean up changelog and readme, and remove external build dependencies (#38)
+- Pinned pitest-junit5-plugin at 0.9 (#59)
+- Moved: Node.drawTree to Nodes (#60)
+
+** Removed
+
+- Removed from Node: getChildByName, getParent, getChild, getData (#60
 
 ** Dependencies
 
+- Bump kemitix-checkstyle-ruleset from 4.0.1 to 5.4.0 (#59)
+- Bump kemitix-parent from 5.2.0 to 5.3.0 (#56)
+- Bump lombok from 1.18.10 to 1.18.12 (#55)
+- Bump assertj-core from 3.13.2 to 3.15.0 (#54)
+- Bump junit from 4.12 to 4.13 (#53)
+- Bump tiles-maven-plugin from 2.15 to 2.16 (#52)
 - Bump hamcrest-core from 2.1 to 2.2 (#50)
 - Bump lombok from 1.18.8 to 1.18.10 (#49)
 - Bump assertj-core from 3.12.2 to 3.13.2 (#48)
@@ -29,7 +42,6 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Bump lombok from 1.18.4 to 1.18.6 (#41)
 - Bump tiles-maven-plugin from 2.12 to 2.13 (#40)
 - Bump hamcrest-core from 1.3 to 2.1 (#37)
-- Clean up changelog and readme, and remove external build dependencies (#38)
 
 * [0.7.0] - 2017-02-18
 

src/main/java/net/kemitix/node/Node.java

@@ -58,13 +58,6 @@ public interface Node<T> {
      */
     Optional<T> findData();
 
-    /**
-     * Fetch the data held within the node.
-     *
-     * @return the node's data, or throws an {@link EmptyNodeException}
-     */
-    T getData();
-
     /**
      * Set the data held within the node.
      *
@@ -93,13 +86,6 @@ public interface Node<T> {
      */
     Optional<Node<T>> findParent();
 
-    /**
-     * Fetch the parent node.
-     *
-     * @return the parent node, or throws an {@link OrphanedNodeException}
-     */
-    Node<T> getParent();
-
     /**
      * Make the current node a direct child of the parent.
      *
@@ -157,15 +143,6 @@ public interface Node<T> {
      */
     Optional<Node<T>> findChild(T child);
 
-    /**
-     * Fetches the node for the child if present.
-     *
-     * @param child the child's data to search for
-     *
-     * @return the child node if found
-     */
-    Node<T> getChild(T child);
-
     /**
      * Checks if the node is an ancestor.
      *
@@ -202,25 +179,6 @@ public interface Node<T> {
      */
     Optional<Node<T>> findChildByName(String name);
 
-    /**
-     * Returns the child with the given name. If one can't be found a
-     * NodeException is thrown.
-     *
-     * @param name the name of the child
-     *
-     * @return the node
-     */
-    Node<T> getChildByName(String name);
-
-    /**
-     * Draw a representation of the tree.
-     *
-     * @param depth current depth for recursion
-     *
-     * @return a representation of the tree
-     */
-    String drawTree(int depth);
-
     /**
      * Returns true if the Node has a name. Where a name supplier is used, the
      * generated name is used.

src/main/java/net/kemitix/node/NodeItem.java

@@ -21,7 +21,9 @@
 
 package net.kemitix.node;
 
+import lombok.Getter;
 import lombok.NonNull;
+import lombok.Setter;
 import lombok.val;
 
 import java.util.*;
@@ -38,15 +40,17 @@ import static net.kemitix.node.HeadTail.tail;
  *
  * @author Paul Campbell (pcampbell@kemitix.net)
  */
-@SuppressWarnings("methodcount")
 class NodeItem<T> implements Node<T> {
 
     private final Set<Node<T>> children = new HashSet<>();
 
+    @Setter
     private T data;
 
     private Node<T> parent;
 
+    @Setter
+    @Getter
     private String name;
 
     /**
@@ -57,13 +61,20 @@ class NodeItem<T> implements Node<T> {
      * @param parent   the parent of the node, or null for a root node
      * @param children the children of the node - must not be null
      */
-    NodeItem(final T data, final String name, final Node<T> parent, @NonNull final Set<Node<T>> children) {
+    NodeItem(
+            final T data,
+            final String name,
+            final Node<T> parent,
+            final Set<Node<T>> children
+    ) {
         this.data = data;
         this.name = name;
         if (parent != null) {
             doSetParent(parent);
         }
-        this.children.addAll(children);
+        if (children != null) {
+            this.children.addAll(children);
+        }
     }
 
     /**
@@ -75,34 +86,11 @@ class NodeItem<T> implements Node<T> {
         this.parent = newParent;
     }
 
-    @Override
-    public String getName() {
-        return name;
-    }
-
-    @Override
-    public void setName(final String name) {
-        this.name = name;
-    }
-
     @Override
     public Optional<T> findData() {
         return Optional.ofNullable(data);
     }
 
-    @Override
-    public T getData() {
-        if (isEmpty()) {
-            throw new EmptyNodeException(getName());
-        }
-        return data;
-    }
-
-    @Override
-    public void setData(final T data) {
-        this.data = data;
-    }
-
     @Override
     public boolean isEmpty() {
         return data == null;
@@ -118,14 +106,6 @@ class NodeItem<T> implements Node<T> {
         return Optional.ofNullable(parent);
     }
 
-    @Override
-    public Node<T> getParent() {
-        if (parent == null) {
-            throw new OrphanedNodeException(getName());
-        }
-        return parent;
-    }
-
     /**
      * Make the current node a direct child of the parent.
      *
@@ -137,7 +117,7 @@ class NodeItem<T> implements Node<T> {
     }
 
     @SuppressWarnings("npathcomplexity")
-    private void doSetParent(@NonNull final Node<T> newParent) {
+    private void doSetParent(final Node<T> newParent) {
         if (this.equals(newParent) || newParent.isDescendantOf(this)) {
             throw new NodeException("Parent is a descendant");
         }
@@ -178,7 +158,7 @@ class NodeItem<T> implements Node<T> {
         }
     }
 
-    private void verifyChildIsNotAnAncestor(final @NonNull Node<T> child) {
+    private void verifyChildIsNotAnAncestor(final Node<T> child) {
         if (this.equals(child) || isDescendantOf(child)) {
             throw new NodeException("Child is an ancestor");
         }
@@ -237,11 +217,6 @@ class NodeItem<T> implements Node<T> {
                 .findFirst();
     }
 
-    @Override
-    public Node<T> getChild(final T child) {
-        return findChild(child).orElseThrow(() -> new NodeException("Child not found"));
-    }
-
     /**
      * Checks if the node is an ancestor.
      *
@@ -323,33 +298,6 @@ class NodeItem<T> implements Node<T> {
                        .findAny();
     }
 
-    @Override
-    public Node<T> getChildByName(final String named) {
-        final Optional<Node<T>> optional = findChildByName(named);
-        if (optional.isPresent()) {
-            return optional.get();
-        }
-        throw new NodeException("Named child not found");
-    }
-
-    @Override
-    @SuppressWarnings("movevariableinsideif")
-    public String drawTree(final int depth) {
-        final StringBuilder sb = new StringBuilder();
-        final String unnamed = "(unnamed)";
-        if (isNamed()) {
-            sb.append(formatByDepth(name, depth));
-        } else if (!children.isEmpty()) {
-            sb.append(formatByDepth(unnamed, depth));
-        }
-        getChildren().forEach(c -> sb.append(c.drawTree(depth + 1)));
-        return sb.toString();
-    }
-
-    private String formatByDepth(final String value, final int depth) {
-        return String.format("[%1$" + (depth + value.length()) + "s]\n", value);
-    }
-
     @Override
     public boolean isNamed() {
         String currentName = getName();

src/main/java/net/kemitix/node/Nodes.java

@@ -85,7 +85,7 @@ public final class Nodes {
      */
     public static <T> Node<T> namedChild(
             final T data, final String name, final Node<T> parent
-                                        ) {
+    ) {
         return new NodeItem<>(data, name, parent, new HashSet<>());
     }
 
@@ -104,23 +104,49 @@ public final class Nodes {
         }
         final Set<Node<T>> children = getImmutableChildren(root);
         return ImmutableNodeItem.newRoot(root.findData()
-                                             .orElse(null), root.getName(), children);
+                .orElse(null), root.getName(), children);
     }
 
     private static <T> Set<Node<T>> getImmutableChildren(final Node<T> source) {
         return source.getChildren()
-                     .stream()
-                     .map(Nodes::asImmutableChild)
-                     .collect(Collectors.toSet());
+                .stream()
+                .map(Nodes::asImmutableChild)
+                .collect(Collectors.toSet());
     }
 
     private static <T> Node<T> asImmutableChild(
             final Node<T> source
-                                               ) {
+    ) {
         return ImmutableNodeItem.newChild(source.findData()
-                                                .orElse(null), source.getName(), source.findParent()
-                                                                                       .orElse(null),
-                                          getImmutableChildren(source)
-                                         );
+                        .orElse(null), source.getName(), source.findParent()
+                        .orElse(null),
+                getImmutableChildren(source)
+        );
+    }
+
+    /**
+     * Draw a representation of the tree.
+     *
+     * @param depth current depth for recursion
+     * @return a representation of the tree
+     */
+    @SuppressWarnings("movevariableinsideif")
+    public static <T> String drawTree(
+            final Node<T> node,
+            final int depth
+    ) {
+        final StringBuilder sb = new StringBuilder();
+        final String unnamed = "(unnamed)";
+        if (node.isNamed()) {
+            sb.append(formatByDepth(node.getName(), depth));
+        } else if (!node.getChildren().isEmpty()) {
+            sb.append(formatByDepth(unnamed, depth));
+        }
+        node.getChildren().forEach(c -> sb.append(drawTree(c, depth + 1)));
+        return sb.toString();
+    }
+
+    private static String formatByDepth(final String value, final int depth) {
+        return String.format("[%1$" + (depth + value.length()) + "s]\n", value);
     }
 }

src/test/java/net/kemitix/node/ImmutableNodeItemTest.java

@@ -11,6 +11,7 @@ import java.util.Arrays;
 import java.util.Collections;
 import java.util.Optional;
 import java.util.stream.Collectors;
+import java.util.stream.Stream;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
@@ -33,18 +34,6 @@ public class ImmutableNodeItemTest {
         exception.expectMessage(IMMUTABLE_OBJECT);
     }
 
-    @Test
-    public void getDataReturnsData() {
-        //given
-        val data = "this immutableNode data";
-        //when
-        immutableNode = Nodes.asImmutable(Nodes.unnamedRoot(data));
-        //then
-        assertThat(immutableNode.getData()).as("can get the data from a immutableNode")
-                                           .
-                                                   contains(data);
-    }
-
     @Test
     public void canCreateAnEmptyAndUnnamedNode() {
         //when
@@ -81,14 +70,15 @@ public class ImmutableNodeItemTest {
     @Test
     public void shouldContainImmutableCopyOfChild() {
         //given
-        val parent = Nodes.unnamedRoot("root");
-        val child = Nodes.namedChild("child", "child", parent);
+        Node<String> parent = Nodes.unnamedRoot("root");
+        Node<String> child = Nodes.namedChild("child", "child", parent);
         //when
         immutableNode = Nodes.asImmutable(parent);
         //then
-        val immutableChild = immutableNode.getChildByName("child");
-        assertThat(immutableChild).isNotSameAs(child);
-        assertThat(immutableChild.getName()).isEqualTo("child");
+        Optional<Node<String>> immutableChild =
+                immutableNode.findChildByName("child");
+        assertThat(immutableChild).isNotEqualTo(Optional.of(child));
+        assertThat(immutableChild.map(Node::getName)).contains("child");
     }
 
     @Test
@@ -100,13 +90,14 @@ public class ImmutableNodeItemTest {
         immutableNode = Nodes.asImmutable(parent);
         //then
         // get the immutable node's child's parent
-        val immutableChild = immutableNode.getChildByName("child");
-        final Optional<Node<String>> optionalParent = immutableChild.findParent();
-        if (optionalParent.isPresent()) {
-            val p = optionalParent.get();
-            assertThat(p).hasFieldOrPropertyWithValue("name", "root")
-                         .hasFieldOrPropertyWithValue("data", "parent");
-        }
+        Optional<Node<String>> foundParent =
+                immutableNode.findChildByName("child")
+                        .flatMap(Node::findParent);
+        assertThat(foundParent).isNotEmpty();
+        foundParent.ifPresent(p ->
+                assertThat(p)
+                        .hasFieldOrPropertyWithValue("name", "root")
+                        .hasFieldOrPropertyWithValue("data", "parent"));
     }
 
     @Test
@@ -215,10 +206,9 @@ public class ImmutableNodeItemTest {
         val result = immutableNode.findChild("child");
         //then
         assertThat(result.isPresent()).isTrue();
-        if (result.isPresent()) {
-            assertThat(result.get()
-                             .getData()).contains("child");
-        }
+        result.map(resultNode ->
+                assertThat(resultNode.findData())
+                        .contains("child"));
     }
 
     /**
@@ -244,9 +234,10 @@ public class ImmutableNodeItemTest {
         root.addChild(beta);
         immutableNode = Nodes.asImmutable(root);
         //when
-        val result = immutableNode.getChildByName("alpha");
+        Optional<Node<String>> result = immutableNode.findChildByName("alpha");
         //then
-        assertThat(result.getName()).isEqualTo(alpha.getName());
+        assertThat(result.map(Node::getName))
+                .contains(alpha.getName());
     }
 
     @Test
@@ -257,11 +248,10 @@ public class ImmutableNodeItemTest {
         val beta = Nodes.namedRoot("beta data", "beta");
         root.addChild(alpha);
         root.addChild(beta);
-        exception.expect(NodeException.class);
-        exception.expectMessage("Named child not found");
         immutableNode = Nodes.asImmutable(root);
-        //when
-        immutableNode.getChildByName("gamma");
+        //then
+        assertThat(immutableNode.findChildByName("gamma"))
+                .isEmpty();
     }
 
     @Test
@@ -316,27 +306,6 @@ public class ImmutableNodeItemTest {
         immutableNode.removeChild(null);
     }
 
-    @Test
-    public void drawTreeIsCorrect() {
-        //given
-        val root = Nodes.namedRoot("root data", "root");
-        val bob = Nodes.namedChild("bob data", "bob", root);
-        val alice = Nodes.namedChild("alice data", "alice", root);
-        Nodes.namedChild("dave data", "dave", alice);
-        Nodes.unnamedChild("bob's child's data", bob); // has no name and no children so no included
-        val kim = Nodes.unnamedChild("kim data", root); // nameless mother
-        Nodes.namedChild("lucy data", "lucy", kim);
-        immutableNode = Nodes.asImmutable(root);
-        //when
-        val tree = immutableNode.drawTree(0);
-        //then
-        String[] lines = tree.split("\n");
-        assertThat(lines).contains("[root]", "[ alice]", "[  dave]", "[ (unnamed)]", "[  lucy]", "[ bob]");
-        assertThat(lines).containsSubsequence("[root]", "[ alice]", "[  dave]");
-        assertThat(lines).containsSubsequence("[root]", "[ (unnamed)]", "[  lucy]");
-        assertThat(lines).containsSubsequence("[root]", "[ bob]");
-    }
-
     @Test
     public void setDataShouldThrowException() {
         //given
@@ -355,28 +324,6 @@ public class ImmutableNodeItemTest {
         immutableNode.createChild("child data", "child name");
     }
 
-    @Test
-    public void canGetChildWhenFound() {
-        //given
-        val root = Nodes.unnamedRoot("data");
-        val child = Nodes.namedChild("child data", "child name", root);
-        immutableNode = Nodes.asImmutable(root);
-        //when
-        val found = immutableNode.getChild("child data");
-        //then
-        assertThat(found.getName()).isEqualTo(child.getName());
-    }
-
-    @Test
-    public void canGetChildWhenNotFound() {
-        //given
-        exception.expect(NodeException.class);
-        exception.expectMessage("Child not found");
-        immutableNode = Nodes.asImmutable(Nodes.unnamedRoot("data"));
-        //when
-        immutableNode.getChild("child data");
-    }
-
     @Test
     public void canSafelyHandleFindChildWhenAChildHasNoData() {
         //given
@@ -437,15 +384,16 @@ public class ImmutableNodeItemTest {
         Nodes.namedChild("eight", "eight", n6);
         val immutableRoot = Nodes.asImmutable(node);
         //when
-        val result = immutableRoot.stream()
-                                  .collect(Collectors.toList());
+        val result = immutableRoot.stream().collect(Collectors.toList());
         //then
-        assertThat(result).as("full tree")
-                          .hasSize(9);
+        assertThat(result).as("full tree").hasSize(9);
         // and
-        assertThat(immutableRoot.getChild("one")
-                                .stream()
-                                .collect(Collectors.toList())).as("sub-tree")
-                                                              .hasSize(4);
+        assertThat(immutableRoot
+                .findChild("one")
+                .map(Node::stream)
+                .map(Stream::count)
+        )
+                .as("sub-tree")
+                .contains(4L);
     }
 }

src/test/java/net/kemitix/node/IsNamedCategory.java

@@ -0,0 +1,4 @@
+package net.kemitix.node;
+
+public interface IsNamedCategory {
+}

src/test/java/net/kemitix/node/NodeItemTest.java

@@ -27,27 +27,6 @@ public class NodeItemTest {
 
     private Node<String> node;
 
-    @Test
-    public void getDataReturnsData() {
-        //given
-        val data = "this node data";
-        //when
-        node = Nodes.unnamedRoot(data);
-        //then
-        assertThat(node.getData()).as("can get the data from a node")
-                                  .contains(data);
-    }
-
-    @Test
-    public void getDataWhenEmptyThrowsException() throws Exception {
-        //given
-        node = Nodes.unnamedRoot(null);
-        assertThat(node.isEmpty()).isTrue();
-        exception.expect(EmptyNodeException.class);
-        //when
-        node.getData();
-    }
-
     @Test
     public void findDataWhenFullReturnsData() {
         //given
@@ -69,26 +48,6 @@ public class NodeItemTest {
         assertThat(result).isEmpty();
     }
 
-    @Test
-    public void getParentWhenRootThrowsException() {
-        //given
-        node = Nodes.unnamedRoot(null);
-        exception.expect(OrphanedNodeException.class);
-        //when
-        node.getParent();
-    }
-
-    @Test
-    public void getParentWhenChildReturnsRoot() {
-        //given
-        val root = Nodes.unnamedRoot("root");
-        node = Nodes.unnamedChild("child", root);
-        //when
-        val result = node.getParent();
-        //then
-        assertThat(result).isSameAs(root);
-    }
-
     @Test
     public void findParentWhenRootReturnsEmptyOptional() {
         //given
@@ -607,34 +566,6 @@ public class NodeItemTest {
         assertThat(node.findData()).isEmpty();
     }
 
-    @Test
-    public void getChildNamedFindsChild() {
-        //given
-        node = Nodes.namedRoot("root data", "root");
-        val alpha = Nodes.namedRoot("alpha data", "alpha");
-        val beta = Nodes.namedRoot("beta data", "beta");
-        node.addChild(alpha);
-        node.addChild(beta);
-        //when
-        val result = node.getChildByName("alpha");
-        //then
-        assertThat(result).isSameAs(alpha);
-    }
-
-    @Test
-    public void getChildNamedFindsNothing() {
-        //given
-        node = Nodes.namedRoot("root data", "root");
-        val alpha = Nodes.namedRoot("alpha data", "alpha");
-        val beta = Nodes.namedRoot("beta data", "beta");
-        node.addChild(alpha);
-        node.addChild(beta);
-        exception.expect(NodeException.class);
-        exception.expectMessage("Named child not found");
-        //when
-        node.getChildByName("gamma");
-    }
-
     @Test
     public void nodeNamesAreUniqueWithinAParent() {
         //given
@@ -656,23 +587,38 @@ public class NodeItemTest {
         //when
         node.insertInPath(four, "one", "two", "three");
         //then
-        val three = four.getParent();
-        assertThat(four.getParent()).as("add node to a tree")
-                                    .isNotNull();
-        assertThat(three.getName()).isEqualTo("three");
-        val two = three.getParent();
-        assertThat(two.getName()).isEqualTo("two");
-        val one = two.getParent();
-        assertThat(one.getName()).isEqualTo("one");
-        assertThat(one.getParent()).isSameAs(node);
-        assertThat(node.getChildByName("one")
-                       .getChildByName("two")
-                       .getChildByName("three")
-                       .getChildByName("four")).isSameAs(four);
+        assertThat(four.findParent())
+                .as("add node to a tree")
+                .isNotEmpty();
+
+        val three = four.findParent();
+        assertThat(three).isNotEmpty();
+        three.map(threeNode ->
+                assertThat(threeNode.getName())
+                        .isEqualTo("three"));
+
+        val two = three.flatMap(Node::findParent);
+        assertThat(two).isNotEmpty();
+        two.map(twoNode ->
+                assertThat(twoNode.getName())
+                        .isEqualTo("two"));
+
+        val one = two.flatMap(Node::findParent);
+        assertThat(one).isNotEmpty();
+        one.ifPresent(oneNode ->
+                SoftAssertions.assertSoftly(softly -> {
+                    assertThat(oneNode.getName()).isEqualTo("one");
+                    assertThat(oneNode.findParent()).contains(node);
+                }));
+        Optional<Node<String>> fourNode = node.findChildByName("one")
+                .flatMap(oneChild -> oneChild.findChildByName("two"))
+                .flatMap(twoChild -> twoChild.findChildByName("three"))
+                .flatMap(threeChild -> threeChild.findChildByName("four"));
+        assertThat(fourNode).isNotEmpty();
+        assertThat(fourNode).contains(four);
     }
 
     @Test
-    @SuppressWarnings("unchecked")
     public void canPlaceInTreeUnderExistingNode() {
         //given
         node = Nodes.namedRoot(null, "root");
@@ -682,15 +628,17 @@ public class NodeItemTest {
         node.insertInPath(child); // as root/child
         node.insertInPath(grandchild, "child"); // as root/child/grandchild
         //then
-        assertThat(node.getChildByName("child")).as("child")
-                                                .isSameAs(child);
-        assertThat(node.getChildByName("child")
-                       .getChildByName("grandchild")).as("grandchild")
-                                                     .isSameAs(grandchild);
+        assertThat(node.findChildByName("child"))
+                .as("child")
+                .contains(child);
+        Optional<Node<String>> grandNode = node.findChildByName("child")
+                .flatMap(childNode -> childNode.findChildByName("grandchild"));
+        assertThat(grandNode)
+                .as("grandchild")
+                .contains(grandchild);
     }
 
     @Test
-    @SuppressWarnings("unchecked")
     public void canPlaceInTreeAboveExistingNode() {
         //given
         node = Nodes.namedRoot(null, "root");
@@ -700,12 +648,14 @@ public class NodeItemTest {
         node.insertInPath(grandchild, "child");
         node.insertInPath(child);
         //then
-        assertThat(node.getChildByName("child")
-                       .getData()).as("data in tree")
-                                  .contains("child data");
-        assertThat(node.getChildByName("child")
-                       .getChildByName("grandchild")).as("grandchild")
-                                                     .isSameAs(grandchild);
+        assertThat(node.findChildByName("child").flatMap(Node::findData))
+                .as("data in tree")
+                .contains("child data");
+        assertThat(
+                node.findChildByName("child").flatMap(childNode ->
+                        childNode.findChildByName("grandchild")))
+                .as("grandchild")
+                .contains(grandchild);
     }
 
     @Test
@@ -756,7 +706,6 @@ public class NodeItemTest {
     }
 
     @Test
-    @SuppressWarnings("unchecked")
     public void placeNodeInTreeWhenEmptyChildWithTargetNameExists() {
         //given
         node = Nodes.unnamedRoot(null);
@@ -764,18 +713,18 @@ public class NodeItemTest {
         final Node<String> target = Nodes.namedRoot(null, "target");
         node.addChild(child);
         child.addChild(target);
-        val addMe = Nodes.namedRoot("I'm new", "target");
+        Node<String> addMe = Nodes.namedRoot("I'm new", "target");
         assertThat(addMe.findParent()).isEmpty();
-        assertThat(child.getChildByName("target")
-                        .isEmpty()).as("target starts empty")
-                                   .isTrue();
+        assertThat(child.findChildByName("target").flatMap(Node::findData))
+                .as("target starts empty")
+                .isEmpty();
         //when
         // addMe should replace target as the sole descendant of child
         node.insertInPath(addMe, "child");
         //then
-        assertThat(child.getChildByName("target")
-                        .getData()).as("target now contains data")
-                                   .contains("I'm new");
+        assertThat(child.findChildByName("target").flatMap(Node::findData))
+                .as("target now contains data")
+                .contains("I'm new");
     }
 
     @Test
@@ -789,14 +738,16 @@ public class NodeItemTest {
     }
 
     @Test
+    @Category(IsNamedCategory.class)
     public void isNamedNull() {
         //given
-        node = Nodes.unnamedRoot(null);
+        node = Nodes.namedRoot(null, null);
         //then
         assertThat(node.isNamed()).isFalse();
     }
 
     @Test
+    @Category(IsNamedCategory.class)
     public void isNamedEmpty() {
         //given
         node = Nodes.namedRoot(null, "");
@@ -805,6 +756,7 @@ public class NodeItemTest {
     }
 
     @Test
+    @Category(IsNamedCategory.class)
     public void isNamedNamed() {
         //given
         node = Nodes.namedRoot(null, "named");
@@ -826,26 +778,6 @@ public class NodeItemTest {
         assertThat(child.findParent()).isEmpty();
     }
 
-    @Test
-    public void drawTreeIsCorrect() {
-        //given
-        node = Nodes.namedRoot(null, "root");
-        val bob = Nodes.namedChild("bob data", "bob", node);
-        val alice = Nodes.namedChild("alice data", "alice", node);
-        Nodes.namedChild("dave data", "dave", alice);
-        Nodes.unnamedChild("bob's child's data", bob); // has no name and no children so no included
-        val kim = Nodes.unnamedChild("kim data", node); // nameless mother
-        Nodes.namedChild("lucy data", "lucy", kim);
-        //when
-        val tree = node.drawTree(0);
-        //then
-        String[] lines = tree.split("\n");
-        assertThat(lines).contains("[root]", "[ alice]", "[  dave]", "[ (unnamed)]", "[  lucy]", "[ bob]");
-        assertThat(lines).containsSubsequence("[root]", "[ alice]", "[  dave]");
-        assertThat(lines).containsSubsequence("[root]", "[ (unnamed)]", "[  lucy]");
-        assertThat(lines).containsSubsequence("[root]", "[ bob]");
-    }
-
     @Test
     public void canChangeNodeData() {
         //given
@@ -853,7 +785,7 @@ public class NodeItemTest {
         //when
         node.setData("updated");
         //then
-        assertThat(node.getData()).contains("updated");
+        assertThat(node.findData()).contains("updated");
     }
 
     @Test
@@ -869,27 +801,6 @@ public class NodeItemTest {
         assertThat(node.getChildren()).containsExactly(child);
     }
 
-    @Test
-    public void canGetChildWhenFound() {
-        //given
-        node = Nodes.unnamedRoot("data");
-        val child = Nodes.namedChild("child data", "child name", node);
-        //when
-        val found = node.getChild("child data");
-        //then
-        assertThat(found).isSameAs(child);
-    }
-
-    @Test
-    public void canGetChildWhenNotFound() {
-        //given
-        exception.expect(NodeException.class);
-        exception.expectMessage("Child not found");
-        node = Nodes.unnamedRoot("data");
-        //when
-        node.getChild("child data");
-    }
-
     @Test
     @SuppressWarnings("unchecked")
     public void constructorWithNameSupplierAndParentBeChildOfParent() {
@@ -969,4 +880,17 @@ public class NodeItemTest {
         assertThat(resultChild1).containsExactlyInAnyOrder(root);
         assertThat(resultChild3).containsExactlyInAnyOrder(child2, root);
     }
+
+    @Test
+    public void whenNodeItemChildrenAreNullThenAsNoChildren() {
+        //when
+        NodeItem<String> nodeItem = new NodeItem<>(
+                "data",
+                "name",
+                null,
+                null);
+        //then
+        assertThat(nodeItem.getChildren())
+                .isEmpty();
+    }
 }

src/test/java/net/kemitix/node/NodeTreeDrawTest.java

@@ -0,0 +1,30 @@
+package net.kemitix.node;
+
+import lombok.val;
+import org.junit.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class NodeTreeDrawTest {
+
+    @Test
+    public void drawTreeIsCorrect() {
+        //given
+        final Node<String> node = Nodes.namedRoot(null, "root");
+        val bob = Nodes.namedChild("bob data", "bob", node);
+        val alice = Nodes.namedChild("alice data", "alice", node);
+        Nodes.namedChild("dave data", "dave", alice);
+        Nodes.unnamedChild("bob's child's data", bob); // has no name and no children so no included
+        val kim = Nodes.unnamedChild("kim data", node); // nameless mother
+        Nodes.namedChild("lucy data", "lucy", kim);
+        //when
+        val tree = Nodes.drawTree(node, 0);
+        //then
+        String[] lines = tree.split("\n");
+        assertThat(lines).contains("[root]", "[ alice]", "[  dave]", "[ (unnamed)]", "[  lucy]", "[ bob]");
+        assertThat(lines).containsSubsequence("[root]", "[ alice]", "[  dave]");
+        assertThat(lines).containsSubsequence("[root]", "[ (unnamed)]", "[  lucy]");
+        assertThat(lines).containsSubsequence("[root]", "[ bob]");
+    }
+
+}

src/test/java/net/kemitix/node/NodesTest.java

@@ -23,7 +23,7 @@ public class NodesTest {
     public void shouldCreateUnnamedRoot() throws Exception {
         val node = Nodes.unnamedRoot("data");
         SoftAssertions softly = new SoftAssertions();
-        softly.assertThat(node.getData()).contains("data");
+        softly.assertThat(node.findData()).contains("data");
         softly.assertThat(node.getName()).isEmpty();
         softly.assertAll();
     }
@@ -32,7 +32,7 @@ public class NodesTest {
     public void shouldCreateNamedRoot() throws Exception {
         val node = Nodes.namedRoot("data", "name");
         SoftAssertions softly = new SoftAssertions();
-        softly.assertThat(node.getData()).contains("data");
+        softly.assertThat(node.findData()).contains("data");
         softly.assertThat(node.getName()).isEqualTo("name");
         softly.assertAll();
     }
@@ -42,7 +42,7 @@ public class NodesTest {
         val parent = Nodes.unnamedRoot("root");
         val node = Nodes.unnamedChild("data", parent);
         SoftAssertions softly = new SoftAssertions();
-        softly.assertThat(node.getData()).contains("data");
+        softly.assertThat(node.findData()).contains("data");
         softly.assertThat(node.getName()).isEmpty();
         softly.assertThat(node.findParent()).contains(parent);
         softly.assertAll();
@@ -53,7 +53,7 @@ public class NodesTest {
         val parent = Nodes.unnamedRoot("root");
         val node = Nodes.namedChild("data", "child", parent);
         SoftAssertions softly = new SoftAssertions();
-        softly.assertThat(node.getData()).contains("data");
+        softly.assertThat(node.findData()).contains("data");
         softly.assertThat(node.getName()).isEqualTo("child");
         softly.assertThat(node.findParent()).contains(parent);
         softly.assertAll();