Merge branch release/0.5.0 into master

Make ImmutableNodeItem extend NodeItem
Upgrade kemitix-parent to 2.1.0
Upgrade lombok to 1.16.10
Upgrade assertj to 3.5.2

CHANGELOG

@@ -1,6 +1,15 @@
 CHANGELOG
 =========
 
+0.5.0
+------
+
+* Make ImmutableNodeItem extend NodeItem
+* Upgrade kemitix-parent to 2.1.0
+* Upgrade lombok to 1.16.10
+* Upgrade assertj to 3.5.2
+* 
+
 0.4.0
 ------
 

LICENSE.txt

@@ -1,3 +1,4 @@
+/*
 The MIT License (MIT)
 
 Copyright (c) 2016 Paul Campbell
@@ -19,3 +20,4 @@ AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 SOFTWARE.
+*/

pom.xml

@@ -2,7 +2,7 @@
 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>node</artifactId>
-    <version>0.4.2</version>
+    <version>0.5.0</version>
     <packaging>jar</packaging>
 
     <name>Node</name>
@@ -11,11 +11,12 @@
     <parent>
         <groupId>net.kemitix</groupId>
         <artifactId>kemitix-parent</artifactId>
-        <version>2.0.0</version>
+        <version>2.1.0</version>
     </parent>
 
     <properties>
-        <assertj.version>3.4.1</assertj.version>
+        <lombok.version>1.16.10</lombok.version>
+        <assertj.version>3.5.2</assertj.version>
         <coveralls-maven-plugin.version>4.2.0</coveralls-maven-plugin.version>
         <trajano-commons-testing.version>2.1.0</trajano-commons-testing.version>
     </properties>
@@ -49,7 +50,7 @@
         <dependency>
             <groupId>org.projectlombok</groupId>
             <artifactId>lombok</artifactId>
-            <version>1.16.8</version>
+            <version>${lombok.version}</version>
         </dependency>
         <dependency>
             <groupId>junit</groupId>

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

@@ -1,155 +0,0 @@
-package net.kemitix.node;
-
-import lombok.NonNull;
-
-import java.util.HashSet;
-import java.util.List;
-import java.util.Optional;
-import java.util.Set;
-
-/**
- * An abstract node item, providing default implementations for most read-only
- * operations.
- *
- * @author Paul Campbell
- *
- * @param <T> the type of data stored in each node
- */
-abstract class AbstractNodeItem<T> implements Node<T> {
-
-    private T data;
-
-    private String name;
-
-    private Node<T> parent;
-
-    private final Set<Node<T>> children;
-
-    protected AbstractNodeItem(
-            final T data, final String name, final Node<T> parent,
-            final Set<Node<T>> children) {
-        this.data = data;
-        this.name = name;
-        this.parent = parent;
-        this.children = children;
-    }
-
-    @Override
-    public String getName() {
-        return name;
-    }
-
-    @Override
-    public Optional<T> getData() {
-        return Optional.ofNullable(data);
-    }
-
-    @Override
-    public boolean isEmpty() {
-        return data == null;
-    }
-
-    @Override
-    public Optional<Node<T>> getParent() {
-        return Optional.ofNullable(parent);
-    }
-
-    @Override
-    public Set<Node<T>> getChildren() {
-        return new HashSet<>(children);
-    }
-
-    /**
-     * Fetches the node for the child if present.
-     *
-     * @param child the child's data to search for
-     *
-     * @return an {@link Optional} containing the child node if found
-     */
-    @Override
-    public Optional<Node<T>> findChild(@NonNull final T child) {
-        return children.stream().filter(node -> {
-            final Optional<T> d = node.getData();
-            return d.isPresent() && d.get().equals(child);
-        }).findAny();
-    }
-
-    @Override
-    public Node<T> getChild(final T child) {
-        return findChild(child).orElseThrow(
-                () -> new NodeException("Child not found"));
-    }
-
-    /**
-     * Checks if the node is an ancestor.
-     *
-     * @param node the potential ancestor
-     *
-     * @return true if the node is an ancestor
-     */
-    @Override
-    public boolean isDescendantOf(final Node<T> node) {
-        return parent != null && (node.equals(parent) || parent.isDescendantOf(
-                node));
-    }
-
-    /**
-     * Walks the node tree using the path to select each child.
-     *
-     * @param path the path to the desired child
-     *
-     * @return the child or null
-     */
-    @Override
-    public Optional<Node<T>> findInPath(@NonNull final List<T> path) {
-        if (path.isEmpty()) {
-            return Optional.empty();
-        }
-        Node<T> current = this;
-        for (T item : path) {
-            final Optional<Node<T>> child = current.findChild(item);
-            if (child.isPresent()) {
-                current = child.get();
-            } else {
-                current = null;
-                break;
-            }
-        }
-        return Optional.ofNullable(current);
-    }
-
-    @Override
-    public Optional<Node<T>> findChildByName(@NonNull final String named) {
-        return children.stream()
-                       .filter(n -> n.getName().equals(named))
-                       .findAny();
-    }
-
-    @Override
-    public Node<T> getChildByName(final String named) {
-        return findChildByName(named).orElseThrow(
-                () -> new NodeException("Named child not found"));
-    }
-
-    @Override
-    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() {
-        return name != null && name.length() > 0;
-    }
-}

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

@@ -1,3 +1,27 @@
+/*
+The MIT License (MIT)
+
+Copyright (c) 2016 Paul Campbell
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+*/
+
 package net.kemitix.node;
 
 import java.util.List;
@@ -11,28 +35,51 @@ import java.util.Set;
  * getData()} they could then modify the original data within the node. This
  * wouldn't affect the integrity of the node tree structure, however.</p>
  *
- * @author Paul Campbell
- *
  * @param <T> the type of data stored in each node
+ *
+ * @author Paul Campbell (pcampbell@kemitix.net)
  */
-final class ImmutableNodeItem<T> extends AbstractNodeItem<T> {
+final class ImmutableNodeItem<T> extends NodeItem<T> {
 
     private static final String IMMUTABLE_OBJECT = "Immutable object";
 
     private ImmutableNodeItem(
-            final T data, final String name, final Node<T> parent,
+            final T data, final String name, final Node<T> parent, final Set<Node<T>> children
-            final Set<Node<T>> children) {
+                             ) {
-        super(data, name, parent, children);
+        super(data, name, null, children);
+        forceParent(parent);
     }
 
+    /**
+     * Creates a new immutable root node.
+     *
+     * @param data     the data of the node
+     * @param name     the name of the node
+     * @param children the children of the node
+     * @param <T>      the type of the data in the node
+     *
+     * @return the new node tree's root node
+     */
     static <T> ImmutableNodeItem<T> newRoot(
-            final T data, final String name, final Set<Node<T>> children) {
+            final T data, final String name, final Set<Node<T>> children
+                                           ) {
         return new ImmutableNodeItem<>(data, name, null, children);
     }
 
+    /**
+     * Creates a new immutable subtree from this child.
+     *
+     * @param data     the data of the node
+     * @param name     the name of the node
+     * @param parent   the mutable parent of the node
+     * @param children the children of the node
+     * @param <T>      the type of the data in the node
+     *
+     * @return the new immutable node
+     */
     static <T> ImmutableNodeItem<T> newChild(
-            final T data, final String name, final Node<T> parent,
+            final T data, final String name, final Node<T> parent, final Set<Node<T>> children
-            final Set<Node<T>> children) {
+                                            ) {
         return new ImmutableNodeItem<>(data, name, parent, children);
     }
 
@@ -71,12 +118,6 @@ final class ImmutableNodeItem<T> extends AbstractNodeItem<T> {
         throw new UnsupportedOperationException(IMMUTABLE_OBJECT);
     }
 
-    @Override
-    public Node<T> findOrCreateChild(final T child) {
-        return findChild(child).orElseThrow(
-                () -> new UnsupportedOperationException(IMMUTABLE_OBJECT));
-    }
-
     @Override
     public void insertInPath(final Node<T> node, final String... path) {
         throw new UnsupportedOperationException(IMMUTABLE_OBJECT);
@@ -91,5 +132,4 @@ final class ImmutableNodeItem<T> extends AbstractNodeItem<T> {
     public void removeParent() {
         throw new UnsupportedOperationException(IMMUTABLE_OBJECT);
     }
-
 }

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

@@ -1,3 +1,27 @@
+/*
+The MIT License (MIT)
+
+Copyright (c) 2016 Paul Campbell
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+*/
+
 package net.kemitix.node;
 
 import java.util.List;
@@ -7,9 +31,9 @@ import java.util.Set;
 /**
  * An interface for tree node items.
  *
- * @author Paul Campbell
- *
  * @param <T> the type of data held in each node
+ *
+ * @author Paul Campbell (pcampbell@kemitix.net)
  */
 public interface Node<T> {
 
@@ -32,8 +56,7 @@ public interface Node<T> {
     /**
      * Fetch the data held within the node.
      *
-     * @return an Optional containing the node's data, or empty if the node has
+     * @return an Optional containing the node's data, or empty if the node has none
-     * none
      */
     Optional<T> getData();
 
@@ -106,20 +129,6 @@ public interface Node<T> {
      */
     void createDescendantLine(List<T> descendants);
 
-    /**
-     * Looks for a child node and returns it, creating a new child node if one
-     * isn't found.
-     *
-     * @param child the child's data to search or create with
-     *
-     * @return the found or created child node
-     *
-     * @deprecated use {@code node.findChild(child).orElseGet(() ->
-     * node.createChild(child))};
-     */
-    @Deprecated
-    Node<T> findOrCreateChild(T child);
-
     /**
      * Fetches the node for the child if present.
      *
@@ -135,8 +144,6 @@ public interface Node<T> {
      * @param child the child's data to search for
      *
      * @return the child node if found
-     *
-     * @throws NodeException if the node is not found
      */
     Node<T> getChild(T child);
 
@@ -183,8 +190,6 @@ public interface Node<T> {
      * @param name the name of the child
      *
      * @return the node
-     *
-     * @throws NodeException if the node is not found
      */
     Node<T> getChildByName(String name);
 

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

@@ -1,9 +1,33 @@
+/*
+The MIT License (MIT)
+
+Copyright (c) 2016 Paul Campbell
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+*/
+
 package net.kemitix.node;
 
 /**
  * Represents an error within the tree node.
  *
- * @author pcampbell
+ * @author Paul Campbell (pcampbell@kemitix.net)
  */
 @SuppressWarnings("serial")
 public class NodeException extends RuntimeException {

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

@@ -1,3 +1,27 @@
+/*
+The MIT License (MIT)
+
+Copyright (c) 2016 Paul Campbell
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+*/
+
 package net.kemitix.node;
 
 import lombok.NonNull;
@@ -12,62 +36,46 @@ import java.util.Set;
 /**
  * Represents a tree of nodes.
  *
- * @author Paul Campbell
- *
  * @param <T> the type of data stored in each node
+ *
+ * @author Paul Campbell (pcampbell@kemitix.net)
  */
 class NodeItem<T> implements Node<T> {
 
-    private T data;
-
     private final Set<Node<T>> children = new HashSet<>();
 
+    private T data;
+
     private Node<T> parent;
 
     private String name;
 
     /**
-     * Create named root node.
+     * Constructor.
      *
-     * @param data the data or null
+     * @param data     the data of the node
-     * @param name the name
+     * @param name     the name of the node
+     * @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) {
+    NodeItem(
-        this(data);
+            final T data, final String name, final Node<T> parent, @NonNull final Set<Node<T>> children
-        this.name = name;
+            ) {
-    }
-
-    /**
-     * Create unnamed root node.
-     *
-     * @param data the data or null
-     */
-    NodeItem(final T data) {
-        this.data = data;
-    }
-
-    /**
-     * Creates a node with a parent.
-     *
-     * @param data   the data or null
-     * @param parent the parent node
-     */
-    NodeItem(final T data, final Node<T> parent) {
-        this.data = data;
-        setParent(parent);
-    }
-
-    /**
-     * Creates a named node with a parent.
-     *
-     * @param data   the data or null
-     * @param name   the name
-     * @param parent the parent node
-     */
-    NodeItem(final T data, final String name, final Node<T> parent) {
         this.data = data;
         this.name = name;
-        setParent(parent);
+        if (parent != null) {
+            doSetParent(parent);
+        }
+        this.children.addAll(children);
+    }
+
+    /**
+     * Sets the parent of a node without updating the parent in the process as {@link #setParent(Node)} does.
+     *
+     * @param newParent The new parent node
+     */
+    protected void forceParent(final Node<T> newParent) {
+        this.parent = newParent;
     }
 
     @Override
@@ -100,6 +108,28 @@ class NodeItem<T> implements Node<T> {
         return Optional.ofNullable(parent);
     }
 
+    /**
+     * Make the current node a direct child of the parent.
+     *
+     * @param parent the new parent node
+     */
+    @Override
+    public void setParent(@NonNull final Node<T> parent) {
+        doSetParent(parent);
+    }
+
+    private void doSetParent(@NonNull final Node<T> newParent) {
+        if (this.equals(newParent) || newParent.isDescendantOf(this)) {
+            throw new NodeException("Parent is a descendant");
+        }
+        if (this.parent != null) {
+            this.parent.getChildren()
+                       .remove(this);
+        }
+        this.parent = newParent;
+        newParent.addChild(this);
+    }
+
     @Override
     public Set<Node<T>> getChildren() {
         return children;
@@ -117,20 +147,20 @@ class NodeItem<T> implements Node<T> {
         children.add(child);
         // update the child's parent if they don't have one or it is not this
         val childParent = child.getParent();
-        if (!childParent.isPresent() || !childParent.get().equals(this)) {
+        if (!childParent.isPresent() || !childParent.get()
+                                                    .equals(this)) {
             child.setParent(this);
         }
     }
 
     private void verifyChildWithSameNameDoesNotAlreadyExist(
-            final @NonNull Node<T> child) {
+            final @NonNull Node<T> child
+                                                           ) {
         if (child.isNamed()) {
-            findChildByName(child.getName())
+            findChildByName(child.getName()).filter(existingChild -> existingChild != child)
-                    .filter(existingChild -> existingChild != child)
+                                            .ifPresent(existingChild -> {
-                    .ifPresent(existingChild -> {
+                                                throw new NodeException("Node with that name already exists here");
-                        throw new NodeException(
+                                            });
-                                "Node with that name already exists here");
-                    });
         }
     }
 
@@ -149,7 +179,7 @@ class NodeItem<T> implements Node<T> {
      */
     @Override
     public Node<T> createChild(@NonNull final T child) {
-        return new NodeItem<>(child, this);
+        return new NodeItem<>(child, "", this, new HashSet<>());
     }
 
     @Override
@@ -169,28 +199,13 @@ class NodeItem<T> implements Node<T> {
     @Override
     public void createDescendantLine(@NonNull final List<T> descendants) {
         if (!descendants.isEmpty()) {
-            findOrCreateChild(descendants.get(0)).createDescendantLine(
+            val child = descendants.get(0);
-                    descendants.subList(1, descendants.size()));
+            val remainingLine = descendants.subList(1, descendants.size());
+            findChild(child).orElseGet(() -> createChild(child))
+                            .createDescendantLine(remainingLine);
         }
     }
 
-    /**
-     * Looks for a child node and returns it, creating a new child node if one
-     * isn't found.
-     *
-     * @param child the child's data to search or create with
-     *
-     * @return the found or created child node
-     *
-     * @deprecated use node.findChild(child).orElseGet(() -> node.createChild
-     * (child));
-     */
-    @Override
-    @Deprecated
-    public Node<T> findOrCreateChild(@NonNull final T child) {
-        return findChild(child).orElseGet(() -> createChild(child));
-    }
-
     /**
      * Fetches the node for the child if present.
      *
@@ -200,19 +215,15 @@ class NodeItem<T> implements Node<T> {
      */
     @Override
     public Optional<Node<T>> findChild(@NonNull final T child) {
-        return children.stream().filter(node -> {
+        return children.stream()
-            final Optional<T> d = node.getData();
+                       .filter(node -> child.equals(node.getData()
-            return d.isPresent() && d.get().equals(child);
+                                                        .orElseGet(() -> null)))
-        }).findAny();
+                       .findFirst();
     }
 
     @Override
     public Node<T> getChild(final T child) {
-        Optional<Node<T>> optional = findChild(child);
+        return findChild(child).orElseThrow(() -> new NodeException("Child not found"));
-        if (optional.isPresent()) {
-            return optional.get();
-        }
-        throw new NodeException("Child not found");
     }
 
     /**
@@ -224,25 +235,7 @@ class NodeItem<T> implements Node<T> {
      */
     @Override
     public boolean isDescendantOf(final Node<T> node) {
-        return parent != null && (node.equals(parent) || parent.isDescendantOf(
+        return parent != null && (node.equals(parent) || parent.isDescendantOf(node));
-                node));
-    }
-
-    /**
-     * Make the current node a direct child of the parent.
-     *
-     * @param parent the new parent node
-     */
-    @Override
-    public final void setParent(@NonNull final Node<T> parent) {
-        if (this.equals(parent) || parent.isDescendantOf(this)) {
-            throw new NodeException("Parent is a descendant");
-        }
-        if (this.parent != null) {
-            this.parent.getChildren().remove(this);
-        }
-        this.parent = parent;
-        parent.addChild(this);
     }
 
     /**
@@ -258,14 +251,9 @@ class NodeItem<T> implements Node<T> {
             return Optional.empty();
         }
         Node<T> current = this;
-        for (T item : path) {
+        for (int i = 0, pathSize = path.size(); i < pathSize && current != null; i++) {
-            final Optional<Node<T>> child = current.findChild(item);
+            current = current.findChild(path.get(i))
-            if (child.isPresent()) {
+                             .orElse(null);
-                current = child.get();
-            } else {
-                current = null;
-                break;
-            }
         }
         return Optional.ofNullable(current);
     }
@@ -275,11 +263,9 @@ class NodeItem<T> implements Node<T> {
         if (path.length == 0) {
             insertChild(nodeItem);
         } else {
-            val item = path[0];
+            val nextInPath = path[0];
-            findChildByName(item)
+            findChildByName(nextInPath).orElseGet(() -> new NodeItem<>(null, nextInPath, this, new HashSet<>()))
-                    .orElseGet(() -> new NodeItem<>(null, item, this))
+                                       .insertInPath(nodeItem, Arrays.copyOfRange(path, 1, path.length));
-                    .insertInPath(nodeItem,
-                            Arrays.copyOfRange(path, 1, path.length));
         }
     }
 
@@ -299,10 +285,10 @@ class NodeItem<T> implements Node<T> {
             val existing = childByName.get();
             if (existing.isEmpty()) {
                 // place any data in the new node into the existing empty node
-                nodeItem.getData().ifPresent(existing::setData);
+                nodeItem.getData()
+                        .ifPresent(existing::setData);
             } else {
-                throw new NodeException("A non-empty node named '"
+                throw new NodeException("A non-empty node named '" + nodeItem.getName() + "' already exists here");
-                        + nodeItem.getName() + "' already exists here");
             }
         } else {
             // nothing with the same name exists
@@ -313,8 +299,9 @@ class NodeItem<T> implements Node<T> {
     @Override
     public Optional<Node<T>> findChildByName(@NonNull final String named) {
         return children.stream()
-                .filter((Node<T> t) -> t.getName().equals(named))
+                       .filter((Node<T> t) -> t.getName()
-                .findAny();
+                                               .equals(named))
+                       .findAny();
     }
 
     @Override

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

@@ -1,13 +1,37 @@
+/*
+The MIT License (MIT)
+
+Copyright (c) 2016 Paul Campbell
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+*/
+
 package net.kemitix.node;
 
-import java.util.Optional;
+import java.util.HashSet;
 import java.util.Set;
 import java.util.stream.Collectors;
 
 /**
  * Utility class for {@link Node} items.
  *
- * @author pcampbell
+ * @author Paul Campbell (pcampbell@kemitix.net)
  */
 public final class Nodes {
 
@@ -23,7 +47,7 @@ public final class Nodes {
      * @return the new node
      */
     public static <T> Node<T> unnamedRoot(final T data) {
-        return new NodeItem<>(data);
+        return new NodeItem<>(data, "", null, new HashSet<>());
     }
 
     /**
@@ -36,7 +60,7 @@ public final class Nodes {
      * @return the new node
      */
     public static <T> Node<T> namedRoot(final T data, final String name) {
-        return new NodeItem<>(data, name);
+        return new NodeItem<>(data, name, null, new HashSet<>());
     }
 
     /**
@@ -49,7 +73,7 @@ public final class Nodes {
      * @return the new node
      */
     public static <T> Node<T> unnamedChild(final T data, final Node<T> parent) {
-        return new NodeItem<>(data, parent);
+        return new NodeItem<>(data, "", parent, new HashSet<>());
     }
 
     /**
@@ -63,8 +87,9 @@ public final class Nodes {
      * @return the new node
      */
     public static <T> Node<T> namedChild(
-            final T data, final String name, final Node<T> parent) {
+            final T data, final String name, final Node<T> parent
-        return new NodeItem<>(data, name, parent);
+                                        ) {
+        return new NodeItem<>(data, name, parent, new HashSet<>());
     }
 
     /**
@@ -76,12 +101,13 @@ public final class Nodes {
      * @return the immutable copy of the tree
      */
     public static <T> Node<T> asImmutable(final Node<T> root) {
-        if (root.getParent().isPresent()) {
+        if (root.getParent()
+                .isPresent()) {
             throw new IllegalArgumentException("source must be the root node");
         }
         final Set<Node<T>> children = getImmutableChildren(root);
-        return ImmutableNodeItem.newRoot(root.getData().orElse(null),
+        return ImmutableNodeItem.newRoot(root.getData()
-                root.getName(), children);
+                                             .orElse(null), root.getName(), children);
     }
 
     private static <T> Set<Node<T>> getImmutableChildren(final Node<T> source) {
@@ -92,16 +118,13 @@ public final class Nodes {
     }
 
     private static <T> Node<T> asImmutableChild(
-            final Node<T> source) {
+            final Node<T> source
-        final Optional<Node<T>> sourceParent = source.getParent();
+                                               ) {
-        if (sourceParent.isPresent()) {
+        return ImmutableNodeItem.newChild(source.getData()
-            return ImmutableNodeItem.newChild(source.getData().orElse(null),
+                                                .orElse(null), source.getName(), source.getParent()
-                    source.getName(), sourceParent.get(),
+                                                                                       .orElse(null),
-                    getImmutableChildren(source));
+                                          getImmutableChildren(source)
-        } else {
+                                         );
-            throw new IllegalArgumentException(
-                    "source must not be the root node");
-        }
     }
 
 }

src/main/java/net/kemitix/node/package-info.java

@@ -1,4 +1,28 @@
+/*
+The MIT License (MIT)
+
+Copyright (c) 2016 Paul Campbell
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+*/
 /**
  * Tree Node implementation.
  */
+
 package net.kemitix.node;

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

@@ -126,7 +126,7 @@ public class ImmutableNodeItemTest {
         immutableNode = Nodes.asImmutable(Nodes.unnamedRoot("subject"));
         expectImmutableException();
         //when
-        immutableNode.setParent(null);
+        immutableNode.setParent(Nodes.unnamedRoot("child"));
     }
 
     @Test
@@ -222,19 +222,6 @@ public class ImmutableNodeItemTest {
         }
     }
 
-    /**
-     * Test that if we pass null we get an exception.
-     */
-    @Test
-    public void findOrCreateChildShouldThrowNPEFWhenChildIsNull() {
-        //given
-        immutableNode = Nodes.asImmutable(Nodes.unnamedRoot("subject"));
-        exception.expect(NullPointerException.class);
-        exception.expectMessage("child");
-        //when
-        immutableNode.findOrCreateChild(null);
-    }
-
     /**
      * Test that we throw an exception when passed null.
      */
@@ -433,22 +420,11 @@ public class ImmutableNodeItemTest {
     }
 
     @Test
-    public void findOrCreateChildShouldReturnChildWhenChildIsFound() {
+    public void AsImmutableShouldThrowIAEWhenNotRoot() {
         //given
-        val root = Nodes.unnamedRoot("");
+        exception.expect(IllegalArgumentException.class);
-        Nodes.namedChild("child", "child", root);
+        exception.expectMessage("source must be the root node");
-        immutableNode = Nodes.asImmutable(root);
         //when
-        val found = immutableNode.findOrCreateChild("child");
+        Nodes.asImmutable(Nodes.unnamedChild("child", Nodes.unnamedRoot("root")));
-        assertThat(found).extracting(Node::getName).contains("child");
-    }
-
-    @Test
-    public void findOrCreateChildShouldThrowExceptionWhenChildNotFound() {
-        //given
-        immutableNode = Nodes.asImmutable(Nodes.unnamedRoot(""));
-        expectImmutableException();
-        //when
-        immutableNode.findOrCreateChild("child");
     }
 }

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

@@ -10,6 +10,7 @@ import org.junit.rules.ExpectedException;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.Optional;
+import java.util.Set;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
@@ -84,6 +85,17 @@ public class NodeItemTest {
                                     .contains(parent);
     }
 
+    @Test
+    public void shouldAddAsChildWhenCreatedWithParent() {
+        //given
+        final Node<String> root = Nodes.namedRoot("root data", "root name");
+        //when
+        final Node<String> child = Nodes.namedChild("child data", "child name", root);
+        //then
+        final Set<Node<String>> children = root.getChildren();
+        assertThat(children).containsExactly(child);
+    }
+
     /**
      * Test that setting the parent on a node where the proposed parent is a
      * child of the node throws an exception.
@@ -457,52 +469,6 @@ public class NodeItemTest {
                         + "is created").isEmpty();
     }
 
-    /**
-     * Test that we can find a child of a node.
-     */
-    @Test
-    public void shouldFindExistingChildNode() {
-        //given
-        node = Nodes.unnamedRoot("subject");
-        val childData = "child";
-        val child = Nodes.unnamedChild(childData, node);
-        //when
-        val found = node.findOrCreateChild(childData);
-        //then
-        assertThat(found).as(
-                "when searching for a child by data, the matching child is "
-                        + "found").isSameAs(child);
-    }
-
-    /**
-     * Test that we create a missing child of a node.
-     */
-    @Test
-    public void shouldFindCreateNewChildNode() {
-        //given
-        node = Nodes.unnamedRoot("subject");
-        val childData = "child";
-        //when
-        val found = node.findOrCreateChild(childData);
-        //then
-        assertThat(found.getData()).as(
-                "when searching for a non-existent child by data, a new node "
-                        + "is created").contains(childData);
-    }
-
-    /**
-     * Test that if we pass null we get an exception.
-     */
-    @Test
-    public void findOrCreateChildShouldThrowNPEFWhenChildIsNull() {
-        //given
-        node = Nodes.unnamedRoot("subject");
-        exception.expect(NullPointerException.class);
-        exception.expectMessage("child");
-        //when
-        node.findOrCreateChild(null);
-    }
-
     /**
      * Test that we can get the node for a child.
      */

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

@@ -24,7 +24,7 @@ public class NodesTest {
         val node = Nodes.unnamedRoot("data");
         SoftAssertions softly = new SoftAssertions();
         softly.assertThat(node.getData()).contains("data");
-        softly.assertThat(node.getName()).isNull();
+        softly.assertThat(node.getName()).isEmpty();
         softly.assertAll();
     }
 
@@ -43,7 +43,7 @@ public class NodesTest {
         val node = Nodes.unnamedChild("data", parent);
         SoftAssertions softly = new SoftAssertions();
         softly.assertThat(node.getData()).contains("data");
-        softly.assertThat(node.getName()).isNull();
+        softly.assertThat(node.getName()).isEmpty();
         softly.assertThat(node.getParent()).contains(parent);
         softly.assertAll();
     }