diff --git a/lib/CreateChildArgument.ts b/lib/CreateChildArgument.ts
new file mode 100644
index 0000000..4ed45e4
--- /dev/null
+++ b/lib/CreateChildArgument.ts
@@ -0,0 +1,4 @@
+import type { DocumentFragment } from './DocumentFragment.ts';
+import type { Node } from './Node.ts';
+
+export type CreateChildArgument = Node | DocumentFragment | string | boolean | number | null | undefined;
diff --git a/lib/Document.ts b/lib/Document.ts
index 94b3bc9..ce57609 100644
--- a/lib/Document.ts
+++ b/lib/Document.ts
@@ -2,10 +2,16 @@ import { JsonML, type JsonMLElement } from './JsonML.js';
 import { Node } from './Node.js';
 import { Element } from './Element.js';
 import { appendChild } from './appendChild.js';
-import { DOCUMENT_NODE } from './constants.js';
+import { DOCUMENT_NODE, XML_DECLARATION } from './constants.js';
 import { domQuery } from './domQuery/index.js';
 import { findAll } from './findAll.js';
 import { isElement } from './isElement.ts';
+import { DocumentFragment } from './DocumentFragment.ts';
+import { NSMap } from './NSMap.ts';
+import { prettyPrint } from './prettyPrint.ts';
+import { simplePrint } from './simplePrint.ts';
+import type { CreateChildArgument } from './CreateChildArgument.ts';
+import type { XMLAttr } from './XMLAttr.ts';
 
 /**
  * This class describes an XML document.
@@ -14,6 +20,8 @@ import { isElement } from './isElement.ts';
  */
 export class Document extends Node {
   root: Element | null = null;
+  /** @ignore */
+  namespaces = new NSMap();
 
   /**
    * Constructs a new Document instance.
@@ -25,6 +33,31 @@ export class Document extends Node {
     this.nodeType = DOCUMENT_NODE;
   }
 
+  /**
+   * Attach a namespace to the document.
+   *
+   * @param namespaceURI The namespace URI to attach.
+   * @param [prefix] Prefix to use on elements belonging to the namespace.
+   */
+  attachNS (namespaceURI: string, prefix = ''): (name: string, attr?: XMLAttr | null, ...children: (CreateChildArgument | CreateChildArgument[])[]) => Element {
+    this.namespaces.add(namespaceURI, prefix);
+    this._updateNS();
+
+    // Return a new create function bound to the namespace
+    return this.createElementNS.bind(this, namespaceURI);
+  }
+
+  /** @ignore */
+  _updateNS () {
+    // ensure that namespaces exist on the root node
+    if (this.root) {
+      for (const [ namespaceURI, prefix ] of this.namespaces.list()) {
+        const key = 'xmlns' + (prefix ? ':' + prefix : '');
+        this.root.setAttribute(key, namespaceURI);
+      }
+    }
+  }
+
   // overwrites super
   get textContent () {
     return this.root ? this.root.textContent : '';
@@ -37,6 +70,60 @@ export class Document extends Node {
     return this.childNodes.filter(isElement);
   }
 
+  /**
+   * Create a new element node.
+   *
+   * @param qualifiedName The local tagName of the element.
+   * @param attr A record of attributes to assign to the new element.
+   *             If the value is null or undefined, the attribute will be omitted.
+   * @param children Nodes to insert as children.
+   *                 Strings will be converted to TextNodes and arrays will be flattened.
+   * @returns A new Element instance.
+   */
+  createElement = (
+    qualifiedName: string,
+    attr: XMLAttr | null | undefined,
+    ...children: (CreateChildArgument | CreateChildArgument[])[]
+  ): Element => {
+    const element = new Element(qualifiedName);
+    if (attr) {
+      for (const [ key, val ] of Object.entries(attr)) {
+        if (val != null) {
+          element.setAttribute(key, String(val));
+        }
+      }
+    }
+    for (const child of children) {
+      element.append(child);
+    }
+    return element;
+  };
+
+  createElementNS = (
+    namespaceURI: string,
+    qualifiedName: string,
+    attr: XMLAttr | null | undefined,
+    ...children: (CreateChildArgument | CreateChildArgument[])[]
+  ): Element => {
+    const ns = this.namespaces.get(namespaceURI);
+    if (!ns) {
+      throw new Error('Unknown namespace ' + namespaceURI);
+    }
+    const element = new Element(ns + ':' + qualifiedName);
+    // can this not be solved by Element(name, attr) ... does the same thing internally, right?
+    if (attr) {
+      for (const [ key, val ] of Object.entries(attr)) {
+        if (val != null) {
+          element.setAttribute(key, String(val));
+        }
+      }
+    }
+    for (const child of children) {
+      element.append(child);
+    }
+    return element;
+  };
+
   /**
    * Return all descendant elements that have the specified tag name.
    *
@@ -77,12 +164,26 @@ export class Document extends Node {
   }
 
   // overwrites super
-  appendChild (node: Element): Element {
-    if (this.root) {
-      throw new Error('A document may only have one child/root element.');
+  appendChild<T extends Node | DocumentFragment> (node: T): T {
+    if (this.root || (node instanceof DocumentFragment && node.childNodes.length > 1)) {
+      throw new Error('A document must have only one child element.');
+    }
+    let root: Element;
+    if (node instanceof DocumentFragment) {
+      if (!(node.childNodes[0] instanceof Element)) {
+        throw new Error('Document root node must be an Element');
+      }
+      root = node.childNodes[0];
+    }
+    else if (node instanceof Element) {
+      root = node;
     }
-    appendChild(this, node);
-    this.root = node;
+    else {
+      throw new Error('Document root node must be an Element');
+    }
+    appendChild(this, root);
+    this.root = root;
+    this._updateNS();
     return node;
   }
 
@@ -94,4 +195,19 @@ export class Document extends Node {
   toJS (): JsonMLElement | [] {
     return this.root ? JsonML(this.root) : [];
   }
+
+  /**
+   * Print the document as a string.
+   *
+   * @param pretty Apply automatic linebreaks and indentation to the output.
+   * @returns The document as an XML string.
+   */
+  print (pretty = false): string {
+    if (!(this.root instanceof Element)) {
+      throw new Error('root element is missing');
+    }
+    return `${XML_DECLARATION}\n` + (
+      pretty ? prettyPrint(this.root) : simplePrint(this.root)
+    );
+  }
 }
diff --git a/lib/DocumentFragment.ts b/lib/DocumentFragment.ts
new file mode 100644
index 0000000..e92aba5
--- /dev/null
+++ b/lib/DocumentFragment.ts
@@ -0,0 +1,43 @@
+import { appendChild } from './appendChild.ts';
+import { DOCUMENT_FRAGMENT_NODE } from './constants.ts';
+import type { Node } from './Node.ts';
+import { prettyPrint } from './prettyPrint.ts';
+import { simplePrint } from './simplePrint.ts';
+
+/**
+ * A class describing a DocumentFragment.
+ */
+export class DocumentFragment {
+  /** The immediate children contained in the fragment. */
+  childNodes: Node[] = [];
+  /** A numerical node type identifier. */
+  nodeType: number = DOCUMENT_FRAGMENT_NODE;
+
+  /**
+   * Appends a child node into the document fragment.
+   *
+   * @param node The new child node
+   * @returns The same node that was passed in.
+   */
+  appendChild<T extends Node | DocumentFragment> (node: T): T {
+    appendChild(this, node);
+    return node;
+  }
+
+  /** @ignore */
+  toString (): string {
+    return '#document-fragment';
+  }
+
+  /**
+   * Print the document as a string.
+   *
+   * @param pretty Apply automatic linebreaks and indentation to the output.
+   * @returns The document as an XML string.
+   */
+  print (pretty = false): string {
+    return pretty
+      ? prettyPrint(this)
+      : simplePrint(this);
+  }
+}
diff --git a/lib/Element.ts b/lib/Element.ts
index b788fa7..580033e 100644
--- a/lib/Element.ts
+++ b/lib/Element.ts
@@ -1,9 +1,13 @@
 import { Node } from './Node.js';
-import { ELEMENT_NODE } from './constants.js';
+import { ELEMENT_NODE, XML_DECLARATION } from './constants.js';
 import { JsonML, type JsonMLElement } from './JsonML.js';
 import { domQuery } from './domQuery/index.js';
 import { findAll } from './findAll.js';
 import { isElement } from './isElement.ts';
+import { TextNode } from './TextNode.ts';
+import type { CreateChildArgument } from './CreateChildArgument.ts';
+import { prettyPrint } from './prettyPrint.ts';
+import { simplePrint } from './simplePrint.ts';
 
 // eslint-disable-next-line @typescript-eslint/unbound-method
 const hasOwnProperty = Object.prototype.hasOwnProperty;
@@ -31,7 +35,7 @@ export class Element extends Node {
    * Constructs a new Element instance.
    *
    * @param tagName The tag name of the node.
-   * @param [attr={}] A collection of attributes to assign.
+   * @param [attr={}] A collection of attributes to assign. Values of null or undefined will be ignored.
    * @param [closed=false] Was the element "self-closed" when read.
    */
   constructor (tagName: string, attr: Record<string, string> = {}, closed: boolean = false) {
@@ -46,7 +50,12 @@ export class Element extends Node {
     this.fullName = tagName;
     this.closed = !!closed;
     // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
-    this.attr = Object.assign(Object.create(null), attr);
+    this.attr = Object.create(null);
+    for (const [ k, v ] of Object.entries(attr)) {
+      if (v != null) {
+        this.setAttribute(k, v);
+      }
+    }
 
     // inherited instance props from Node
     this.nodeName = this.tagName.toUpperCase();
@@ -72,6 +81,18 @@ export class Element extends Node {
     return this.childNodes.filter(isElement);
   }
 
+  /**
+   * Returns an element's first child Element, or null if there are no child elements
+   */
+  get firstElementChild (): Element | null {
+    for (const child of this.childNodes) {
+      if (isElement(child)) {
+        return child;
+      }
+    }
+    return null;
+  }
+
   /**
    * Read an attribute from the element.
    *
@@ -88,8 +109,8 @@ export class Element extends Node {
    * @param name The attribute name to read.
    * @param value The value to set
    */
-  setAttribute (name: string, value: string) {
-    this.attr[name] = value;
+  setAttribute (name: string, value: string | number | boolean) {
+    this.attr[name] = String(value);
   }
 
   /**
@@ -111,6 +132,46 @@ export class Element extends Node {
     delete this.attr[name];
   }
 
+  get className (): string {
+    return this.getAttribute('class') ?? '';
+  }
+
+  set className (val: unknown) {
+    this.setAttribute('class', String(val));
+  }
+
+  /**
+   * Inserts a set of Node objects or strings after the last child of the Element.
+   * Strings are inserted as equivalent Text nodes.
+   */
+  append (...nodes: (CreateChildArgument | CreateChildArgument[])[]): void {
+    const flatNodes = nodes.flat();
+    for (const n of flatNodes) {
+      if (typeof n === 'string' || typeof n === 'number' || typeof n === 'boolean') {
+        this.appendChild(new TextNode(n));
+      }
+      else if (n) {
+        this.appendChild(n);
+      }
+    }
+  }
+
+  /**
+   * Insert a set of Node objects or strings before the first child of the Element.
+   * Strings are inserted as equivalent Text nodes.
+   */
+  prepend (...nodes: (CreateChildArgument | CreateChildArgument[])[]): void {
+    const flatNodes = nodes.flat();
+    for (const n of flatNodes) {
+      if (typeof n === 'string' || typeof n === 'number' || typeof n === 'boolean') {
+        this.insertBefore(new TextNode(n), this.firstChild);
+      }
+      else if (n) {
+        this.insertBefore(n, this.firstChild);
+      }
+    }
+  }
+
   /**
    * Return all descendant elements that have the specified tag name.
    *
@@ -159,4 +220,16 @@ export class Element extends Node {
   toJS (): JsonMLElement {
     return JsonML(this);
   }
+
+  /**
+   * Print the document as a string.
+   *
+   * @param pretty Apply automatic linebreaks and indentation to the output.
+   * @returns The document as an XML string.
+   */
+  print (pretty = false): string {
+    return `${XML_DECLARATION}\n` + (
+      pretty ? prettyPrint(this) : simplePrint(this)
+    );
+  }
 }
diff --git a/lib/NSMap.ts b/lib/NSMap.ts
new file mode 100644
index 0000000..08d52bc
--- /dev/null
+++ b/lib/NSMap.ts
@@ -0,0 +1,27 @@
+export class NSMap {
+  uriToPre: Record<string, string> = {};
+  preToUri: Record<string, string> = {};
+
+  get (nsURI: string): string | undefined {
+    return this.uriToPre[nsURI];
+  }
+
+  getByPrefix (nsPrefix: string): string | undefined {
+    return this.preToUri[nsPrefix];
+  }
+
+  list (): [string, string][] {
+    return Array.from(Object.entries(this.uriToPre));
+  }
+
+  add (nsURI: string, nsPrefix: string) {
+    if ((nsURI in this.uriToPre) && (this.uriToPre[nsURI] !== nsPrefix)) {
+      throw new Error(nsURI + ' allready has a different prefix');
+    }
+    if ((nsPrefix in this.preToUri) && (this.preToUri[nsPrefix] !== nsPrefix)) {
+      throw new Error(nsPrefix + ' allready has a different URI');
+    }
+    this.uriToPre[nsURI] = nsPrefix;
+    this.preToUri[nsPrefix] = nsURI;
+  }
+}
diff --git a/lib/Node.spec.ts b/lib/Node.spec.ts
new file mode 100644
index 0000000..496f920
--- /dev/null
+++ b/lib/Node.spec.ts
@@ -0,0 +1,319 @@
+import { describe, it, expect } from 'vitest';
+import { Node } from './Node.ts';
+import { Element } from './Element.ts';
+import { TextNode } from './TextNode.ts';
+import { CDataNode } from './CDataNode.ts';
+import { DocumentFragment } from './DocumentFragment.ts';
+
+describe('Node', () => {
+  describe('constructor / default properties', () => {
+    it('has expected default property values', () => {
+      const node = new Node();
+      expect(node.childNodes).toEqual([]);
+      expect(node.nodeName).toBe('#node');
+      expect(node.nodeType).toBe(0);
+      expect(node.parentNode).toBeNull();
+    });
+  });
+
+  describe('appendChild', () => {
+    it('appends a child node and sets parentNode', () => {
+      const parent = new Node();
+      const child = new Node();
+      parent.appendChild(child);
+      expect(parent.childNodes).toContain(child);
+      expect(child.parentNode).toBe(parent);
+    });
+
+    it('returns the appended node', () => {
+      const parent = new Node();
+      const child = new Node();
+      const result = parent.appendChild(child);
+      expect(result).toBe(child);
+    });
+
+    it('throws when called with no argument, null or undefined', () => {
+      const parent = new Node();
+      // @ts-expect-error - testing runtime error
+      expect(() => parent.appendChild()).toThrow('1 argument required');
+      // @ts-expect-error - testing runtime error
+      expect(() => parent.appendChild(null)).toThrow();
+      // @ts-expect-error - testing runtime error
+      expect(() => parent.appendChild(undefined)).toThrow();
+    });
+
+    it('throws when called with a non-node value', () => {
+      const parent = new Node();
+      // @ts-expect-error - testing runtime error
+      expect(() => parent.appendChild('hello')).toThrow('Cannot appendChild');
+      // @ts-expect-error - testing runtime error
+      expect(() => parent.appendChild(42)).toThrow('Cannot appendChild');
+      // @ts-expect-error - testing runtime error
+      expect(() => parent.appendChild({})).toThrow('Cannot appendChild');
+    });
+
+    it('moves a child from one parent to another', () => {
+      const parent1 = new Node();
+      const parent2 = new Node();
+      const child = new Node();
+      parent1.appendChild(child);
+      expect(parent1.childNodes).toContain(child);
+      expect(child.parentNode).toBe(parent1);
+      parent2.appendChild(child);
+      expect(parent1.childNodes).not.toContain(child);
+      expect(parent2.childNodes).toContain(child);
+      expect(child.parentNode).toBe(parent2);
+    });
+
+    it('appends multiple children in order', () => {
+      const parent = new Node();
+      const a = parent.appendChild(new Node());
+      const b = parent.appendChild(new Node());
+      const c = parent.appendChild(new Node());
+      expect(parent.childNodes).toEqual([ a, b, c ]);
+    });
+
+    it('appends DocumentFragment children in order', () => {
+      const frag = new DocumentFragment();
+      const a = frag.appendChild(new Node());
+      const b = frag.appendChild(new Node());
+      const c = frag.appendChild(new Node());
+      expect(frag.childNodes).toEqual([ a, b, c ]);
+
+      const parent = new Node();
+      parent.appendChild(frag);
+      expect(parent.childNodes).toEqual([ a, b, c ]);
+    });
+
+    it('re-appending an existing child moves it to the end', () => {
+      const parent = new Node();
+      const a = new Node();
+      const b = new Node();
+      parent.appendChild(a);
+      parent.appendChild(b);
+      expect(parent.childNodes).toEqual([ a, b ]);
+
+      parent.appendChild(a);
+      expect(parent.childNodes).toEqual([ b, a ]);
+    });
+  });
+
+  describe('insertBefore', () => {
+    it('inserts a node before a reference node', () => {
+      const parent = new Node();
+      const a = new Node();
+      const b = new Node();
+      const c = new Node();
+      parent.appendChild(a);
+      parent.appendChild(c);
+
+      parent.insertBefore(b, c);
+      expect(b.parentNode).toBe(parent);
+      expect(parent.childNodes.filter(d => d === b).length).toBe(1);
+    });
+
+    it('inserts DocumentFragment children in order', () => {
+      const frag = new DocumentFragment();
+      const a = frag.appendChild(new Node());
+      const b = frag.appendChild(new Node());
+      const c = frag.appendChild(new Node());
+      expect(frag.childNodes).toEqual([ a, b, c ]);
+
+      const parent = new Node();
+      const z = new Node();
+      parent.appendChild(z); // parent now only contains z
+
+      parent.insertBefore(frag, z);
+      expect(parent.childNodes).toEqual([ a, b, c, z ]);
+    });
+
+    it('falls back to appendChild when referenceNode is null', () => {
+      const parent = new Node();
+      const child = new Node();
+      parent.insertBefore(child, null);
+      expect(parent.childNodes).toContain(child);
+      expect(child.parentNode).toBe(parent);
+    });
+
+    it('moves node from previous parent when inserting', () => {
+      const oldParent = new Node();
+      const newParent = new Node();
+      const ref = new Node();
+      const child = new Node();
+
+      oldParent.appendChild(child);
+      newParent.appendChild(ref);
+
+      newParent.insertBefore(child, ref);
+      expect(oldParent.childNodes).not.toContain(child);
+      expect(child.parentNode).toBe(newParent);
+    });
+  });
+
+  describe('removeChild', () => {
+    it('removes a child and returns it', () => {
+      const parent = new Node();
+      const child = new Node();
+      parent.appendChild(child);
+      const removed = parent.removeChild(child);
+      expect(removed).toBe(child);
+      expect(parent.childNodes).not.toContain(child);
+      expect(child.parentNode).toBeNull();
+    });
+
+    it('throws when no argument is provided', () => {
+      const parent = new Node();
+      // @ts-expect-error - testing runtime error
+      expect(() => parent.removeChild()).toThrow('not of type');
+      // @ts-expect-error - testing runtime error
+      expect(() => parent.removeChild(null)).toThrow('not of type');
+      // @ts-expect-error - testing runtime error
+      expect(() => parent.removeChild(undefined)).toThrow('not of type');
+    });
+
+    it('throws when the node is not a child', () => {
+      const parent = new Node();
+      const orphan = new Node();
+      expect(() => parent.removeChild(orphan)).toThrow(
+        'The node to be removed is not a child of this node.'
+      );
+    });
+
+    it('removes the correct child when there are multiple', () => {
+      const parent = new Node();
+      const a = new Node();
+      const b = new Node();
+      const c = new Node();
+      parent.appendChild(a);
+      parent.appendChild(b);
+      parent.appendChild(c);
+
+      parent.removeChild(b);
+      expect(parent.childNodes).toEqual([ a, c ]);
+      expect(b.parentNode).toBeNull();
+    });
+
+    it('allows removing and re-adding a child', () => {
+      const parent = new Node();
+      const child = new Node();
+      parent.appendChild(child);
+      parent.removeChild(child);
+      expect(parent.childNodes.length).toBe(0);
+      expect(child.parentNode).toBeNull();
+
+      parent.appendChild(child);
+      expect(parent.childNodes).toEqual([ child ]);
+      expect(child.parentNode).toBe(parent);
+    });
+  });
+
+  describe('preserveSpace', () => {
+    it('returns false by default on a root node', () => {
+      const node = new Node();
+      expect(node.preserveSpace).toBe(false);
+    });
+
+    it('inherits preserveSpace from parent', () => {
+      // Use an Element with xml:space="preserve" as parent
+      const parent = new Element('root', { 'xml:space': 'preserve' });
+      const child = new Node();
+      parent.appendChild(child);
+      expect(child.preserveSpace).toBe(true);
+    });
+
+    it('returns false when parent does not preserve space', () => {
+      const parent = new Node();
+      const child = new Node();
+      parent.appendChild(child);
+      expect(child.preserveSpace).toBe(false);
+    });
+
+    it('propagates through multiple levels of ancestry', () => {
+      const grandparent = new Element('root', { 'xml:space': 'preserve' });
+      const parent = new Node();
+      const child = new Node();
+      grandparent.appendChild(parent);
+      parent.appendChild(child);
+      expect(child.preserveSpace).toBe(true);
+    });
+  });
+
+  describe('textContent', () => {
+    it('returns empty string for a node with no children', () => {
+      const node = new Node();
+      expect(node.textContent).toBe('');
+    });
+
+    it('returns text from TextNode children', () => {
+      const parent = new Node();
+      const text = new TextNode('hello world');
+      parent.appendChild(text);
+      expect(parent.textContent).toBe('hello world');
+    });
+
+    it('concatenates text from multiple TextNode children', () => {
+      // A whitespace-only TextNode returns '' when preserveSpace is false,
+      // so 'foo' + '' + 'bar' = 'foobar'
+      const parent = new Node();
+      parent.appendChild(new TextNode('foo'));
+      parent.appendChild(new TextNode(' '));
+      parent.appendChild(new TextNode('bar'));
+      expect(parent.textContent).toBe('foobar');
+    });
+
+    it('concatenates text including spaces when preserveSpace is true', () => {
+      const parent = new Element('div', { 'xml:space': 'preserve' });
+      parent.appendChild(new TextNode('foo'));
+      parent.appendChild(new TextNode(' '));
+      parent.appendChild(new TextNode('bar'));
+      expect(parent.textContent).toBe('foo bar');
+    });
+
+    it('collects text content from nested children recursively', () => {
+      const root = new Element('root');
+      const child = new Element('child');
+      const text = new TextNode('deep');
+      root.appendChild(child);
+      child.appendChild(text);
+      expect(root.textContent).toBe('deep');
+    });
+
+    it('includes CDataNode values', () => {
+      const parent = new Node();
+      parent.appendChild(new TextNode('before'));
+      parent.appendChild(new CDataNode(' cdata '));
+      parent.appendChild(new TextNode('after'));
+      expect(parent.textContent).toBe('before cdata after');
+    });
+
+    it('returns empty string for whitespace-only TextNode children (no preserveSpace)', () => {
+      const parent = new Element('div');
+      parent.appendChild(new TextNode('   '));
+      // TextNode with only whitespace returns '' when preserveSpace is false
+      expect(parent.textContent).toBe('');
+    });
+
+    it('preserves whitespace-only TextNode when preserveSpace is true', () => {
+      const parent = new Element('div', { 'xml:space': 'preserve' });
+      parent.appendChild(new TextNode('   '));
+      expect(parent.textContent).toBe('   ');
+    });
+  });
+
+  describe('toString', () => {
+    it('returns a string', () => {
+      const node = new Node();
+      expect(typeof node.toString()).toBe('string');
+    });
+
+    it('renders child elements to XML', () => {
+      const root = new Element('root');
+      const child = new Element('child');
+      root.appendChild(child);
+      const str = root.toString();
+      expect(str).toContain('<root>');
+      expect(str).toContain('<child');
+      expect(str).toContain('</root>');
+    });
+  });
+});
diff --git a/lib/Node.ts b/lib/Node.ts
index 4d6438b..6062825 100644
--- a/lib/Node.ts
+++ b/lib/Node.ts
@@ -1,4 +1,5 @@
 import { appendChild } from './appendChild.js';
+import { DocumentFragment } from './DocumentFragment.ts';
 import { prettyPrint } from './prettyPrint.js';
 
 /**
@@ -14,23 +15,83 @@ export class Node {
   /** The node's parent node. */
   parentNode: Node | null = null;
 
+  /**
+   * Returns the node's first child in the tree, or null if the node has no children.
+   */
+  get firstChild (): Node | null {
+    return this.childNodes.at(0) ?? null;
+  }
+
+  /**
+   * Returns the node's last child in the tree, or null if the node has no children.
+   */
+  get lastChild (): Node | null {
+    return this.childNodes.at(-1) ?? null;
+  }
+
   /**
    * Appends a child node into the current one.
    *
    * @param node The new child node
    * @returns The same node that was passed in.
    */
-  appendChild (node: Node): Node {
+  appendChild<T extends Node | DocumentFragment> (node: T): T {
     if (!node) {
       throw new Error('1 argument required, but 0 present.');
     }
-    if (!(node instanceof Node)) {
+    if (!(node instanceof Node) && !(node instanceof DocumentFragment)) {
       throw new Error('Cannot appendChild: Child is not a node');
     }
     appendChild(this, node);
     return node;
   }
 
+  /**
+   * Inserts a node before a _reference node_ as a child of a specified _parent node_.
+   *
+   * @param newNode The node to be inserted.
+   * @param referenceNode The node before which newNode is inserted. If this is null, then newNode is inserted at the end of node's child nodes.
+   * @returns The added child (unless newNode is a DocumentFragment, in which case the empty DocumentFragment is returned).
+   */
+  insertBefore<T extends Node | DocumentFragment> (newNode: T, referenceNode: Node | null): T {
+    if (referenceNode) {
+      const index = this.childNodes.indexOf(referenceNode);
+      if (index > -1) {
+        const insertNodes = newNode instanceof Node ? [ newNode ] : newNode.childNodes;
+        // update parentage for all the new nodes
+        for (const node of insertNodes) {
+          node.parentNode?.removeChild(node);
+          node.parentNode = this;
+        }
+        // insert the new nodes
+        this.childNodes.splice(index, 0, ...insertNodes);
+      }
+      return newNode;
+    }
+    return this.appendChild(newNode);
+  }
+
+  /**
+   * Removes a child node from the DOM and returns the removed node.
+   * @param node The child node to be removed.
+   * @returns The removed child node.
+   */
+  removeChild (child: Node) {
+    if (!child) {
+      throw new TypeError('parameter 1 is not of type \'Node\'');
+    }
+    const index = this.childNodes.indexOf(child);
+    if (index === -1) {
+      // DOMException
+      throw new Error('The node to be removed is not a child of this node.');
+    }
+    const node = this.childNodes.splice(index, 1).at(0);
+    if (node) {
+      node.parentNode = null;
+    }
+    return node;
+  }
+
   /**
    * True if xml:space has been set to true for this node or any of its ancestors.
    */
diff --git a/lib/TextNode.ts b/lib/TextNode.ts
index 5cd7848..cc86cae 100644
--- a/lib/TextNode.ts
+++ b/lib/TextNode.ts
@@ -12,13 +12,14 @@ export class TextNode extends Node {
 
   /**
    * Constructs a new TextNode instance.
-   * @param {string} [value] The data for the node
+   *
+   * @param [value] The data for the node.
    */
-  constructor (value: string) {
+  constructor (value: any) {
     super();
     this.nodeName = '#text';
     this.nodeType = TEXT_NODE;
-    this.value = value || '';
+    this.value = String(value);
   }
 
   // overwrites super
diff --git a/lib/XMLAttr.ts b/lib/XMLAttr.ts
new file mode 100644
index 0000000..f69dbdf
--- /dev/null
+++ b/lib/XMLAttr.ts
@@ -0,0 +1 @@
+export type XMLAttr = Record<string, string | number | boolean | null | undefined>;
diff --git a/lib/appendChild.ts b/lib/appendChild.ts
index 78e8bb3..83f3c2a 100644
--- a/lib/appendChild.ts
+++ b/lib/appendChild.ts
@@ -1,11 +1,25 @@
-import { Node } from './Node.js';
+import { DocumentFragment } from './DocumentFragment.ts';
+import type { Node } from './Node.js';
 
-export function appendChild (parent: Node, child: Node) {
-  // if node is attached to a parent, first detach it
-  if (child.parentNode) {
-    const p = child.parentNode;
-    p.childNodes = p.childNodes.filter(d => d !== child);
-  }
-  child.parentNode = parent;
-  parent.childNodes.push(child);
+export function appendChild (parent: Node | DocumentFragment, child: Node | DocumentFragment) {
+  if (child instanceof DocumentFragment) {
+    // perform an append operation for every child in the fragment
+    for (const d of child.childNodes) {
+      appendChild(parent, d);
+    }
+  }
+  else if (parent === child) {
+    // XXX: there should really be a more elaborate tests here to determine that child does not contain parent
+    throw new Error('The new child element contains the parent.');
+  }
+  else if (parent instanceof DocumentFragment) {
+    // appending to a fragment does not mess with the node's parentage
+    parent.childNodes.push(child);
+  }
+  else {
+    // if node is attached to a parent, first detach it
+    child.parentNode?.removeChild(child);
+    child.parentNode = parent;
+    parent.childNodes.push(child);
+  }
 }
diff --git a/lib/constants.ts b/lib/constants.ts
index b90e410..2ba3228 100644
--- a/lib/constants.ts
+++ b/lib/constants.ts
@@ -33,3 +33,5 @@ export const DOCUMENT_FRAGMENT_NODE: number = 11;
 
 /** A documentation node identifier */
 export const NOTATION_NODE: number = 12;
+
+export const XML_DECLARATION = '<?xml version="1.0" encoding="UTF-8" standalone="yes"?>';
diff --git a/lib/escape.ts b/lib/escape.ts
index cd6d597..5ea8b7b 100644
--- a/lib/escape.ts
+++ b/lib/escape.ts
@@ -9,9 +9,10 @@ const entities: Record<string, string> = {
 };
 
 /**
- * @ignore
+ * Escape XML entities in a string.
+ *
  * @param {string} s Unescaped string
- * @returns {string} XML escaped string
+ * @returns {string} Escaped string
  */
 export function escape (s: string): string {
   // eslint-disable-next-line no-control-regex
diff --git a/lib/index.ts b/lib/index.ts
index 390e19e..f6280d4 100644
--- a/lib/index.ts
+++ b/lib/index.ts
@@ -4,6 +4,13 @@ export { Element } from './Element.js';
 export { Document } from './Document.js';
 export { TextNode } from './TextNode.js';
 export { CDataNode } from './CDataNode.js';
+export { DocumentFragment } from './DocumentFragment.ts';
+export { escape as escapeXML } from './escape.ts';
+export { isElement } from './isElement.ts';
+export { prettyPrint } from './prettyPrint.ts';
+export { simplePrint } from './simplePrint.ts';
+export type { CreateChildArgument } from './CreateChildArgument.js';
+export type { XMLAttr } from './XMLAttr.js';
 export type { JsonMLElement, JsonMLAttr } from './JsonML.js';
 export {
   ELEMENT_NODE,
diff --git a/lib/parser.ts b/lib/parser.ts
index d21144f..575d0b1 100644
--- a/lib/parser.ts
+++ b/lib/parser.ts
@@ -238,6 +238,7 @@ function posToLine (pos: number, src: string): number {
  * @param [options={}] Parsing options.
  * @param [options.emptyDoc=false] Permit "rootless" documents.
  * @param [options.laxAttr=false] Permit unquoted attributes (`<node foo=bar />`).
+ * @param [options.ns=false] Validate xmlns and element namespaces as they are parsed.
  * @returns A DOM representing the XML node tree.
  */
 export function parseXML (
@@ -245,11 +246,13 @@ export function parseXML (
   options: {
     emptyDoc?: boolean;
     laxAttr?: boolean;
+    ns?: boolean;
   } = DEFAULTOPTIONS
 ): Document {
   // 2.11: before parsing, translate both the two-character sequence
   // \r\n and any \r that is not followed by \n to a single \n
   const xml = removeCR(source);
+  const doc = new Document();
 
   let pos = 0;
   let root = NON_ELEMENT;
@@ -290,6 +293,20 @@ export function parseXML (
     while (m);
   }
 
+  function checkNS (elm: Element) {
+    for (const key in elm.attr) {
+      if (key === 'xmlns') {
+        doc.attachNS(elm.attr[key], '');
+      }
+      if (key.startsWith('xmlns:')) {
+        doc.attachNS(elm.attr[key], key.slice(6));
+      }
+    }
+    if (elm.ns && !doc.namespaces.getByPrefix(elm.ns)) {
+      throw new Error('Unknown namespace prefix ' + elm.ns);
+    }
+  }
+
   // BOM
   if (xml.charCodeAt(pos) === 65279) {
     pos++;
@@ -316,6 +333,7 @@ export function parseXML (
   // root tag
   maybeMatchFn(fnTag, (_, t, a, c) => {
     root = new Element(t, parseAttr(a, options.laxAttr), !!c);
+    if (options.ns) checkNS(root);
     return true;
   });
 
@@ -351,7 +369,9 @@ export function parseXML (
         })
         ||
         maybeMatchFn(fnTag, (_, t, a, c) => {
-          const elm = new Element(t, parseAttr(a, options.laxAttr), !!c);
+          const attr = parseAttr(a, options.laxAttr);
+          const elm = new Element(t, attr, !!c);
+          if (options.ns) checkNS(elm);
           current?.appendChild(elm);
           if (!elm.closed) {
             current = elm;
@@ -384,7 +404,6 @@ export function parseXML (
     throw new Error(`Expected </${root.tagName}> got EOF`);
   }
 
-  const doc = new Document();
   if (root !== NON_ELEMENT) {
     doc.appendChild(root);
   }
diff --git a/lib/prettyPrint.ts b/lib/prettyPrint.ts
index 2f8e036..7634473 100644
--- a/lib/prettyPrint.ts
+++ b/lib/prettyPrint.ts
@@ -1,5 +1,5 @@
 import type { CDataNode } from './CDataNode.ts';
-import type { Document } from './Document.ts';
+import { DocumentFragment } from './DocumentFragment.ts';
 import type { Node } from './Node.js';
 import type { TextNode } from './TextNode.ts';
 import { CDATA_SECTION_NODE, DOCUMENT_NODE, ELEMENT_NODE, TEXT_NODE } from './constants.js';
@@ -25,16 +25,19 @@ function printCData (node: CDataNode) {
   return `<![CDATA[${node.value.replace(/]]>/g, ']]&gt;')}]]>`;
 }
 
-function printDocument (node: Node): string {
+function printDocument (node: Node | DocumentFragment): string {
   return node.childNodes
     .map(n => prettyPrint(n))
     .join('\n');
 }
 
-export function prettyPrint (node: Node, indent: string = ''): string {
+export function prettyPrint (node: Node | DocumentFragment, indent: string = ''): string {
+  if (node instanceof DocumentFragment) {
+    return printDocument(node);
+  }
   const { preserveSpace } = node;
   if (node.nodeType === DOCUMENT_NODE) {
-    return printDocument(node as Document);
+    return printDocument(node);
   }
   else if (node.nodeType === CDATA_SECTION_NODE) {
     return printCData(node as CDataNode);
@@ -43,7 +46,7 @@ export function prettyPrint (node: Node, indent: string = ''): string {
     return printTextNode(node as TextNode);
   }
   else if (isElement(node)) {
-    const tagName = node.tagName;
+    const tagName = node.fullName;
     const { childNodes } = node;
     let children = '';
 
diff --git a/lib/simplePrint.ts b/lib/simplePrint.ts
new file mode 100644
index 0000000..9229214
--- /dev/null
+++ b/lib/simplePrint.ts
@@ -0,0 +1,44 @@
+import type { CDataNode } from './CDataNode.ts';
+import type { Document } from './Document.ts';
+import { DocumentFragment } from './DocumentFragment.ts';
+import type { Node } from './Node.js';
+import type { TextNode } from './TextNode.ts';
+import { CDATA_SECTION_NODE, DOCUMENT_NODE, TEXT_NODE } from './constants.js';
+import { escape } from './escape.js';
+import { isElement } from './isElement.ts';
+
+export function simplePrint (node: Node | DocumentFragment): string {
+  if (node instanceof DocumentFragment) {
+    return node.childNodes.map(n => simplePrint(n)).join('');
+  }
+  if (node.nodeType === DOCUMENT_NODE) {
+    const root = (node as Document).root;
+    if (!root) throw new Error('root element is missing');
+    return simplePrint(root);
+  }
+  else if (node.nodeType === CDATA_SECTION_NODE) {
+    return `<![CDATA[${(node as CDataNode).value.replace(/]]>/g, ']]&gt;')}]]>`;
+  }
+  else if (node.nodeType === TEXT_NODE) {
+    return escape((node as TextNode).value);
+  }
+  else if (isElement(node)) {
+    const tagName = node.fullName;
+    const { childNodes } = node;
+    let children = '';
+    for (const n of childNodes) {
+      children += simplePrint(n);
+    }
+    let attrList = '';
+    if (isElement(node)) {
+      const attr = node.attr;
+      for (const [ key, val ] of Object.entries(attr)) {
+        attrList += ` ${escape(key)}="${escape(val)}"`;
+      }
+    }
+    return children
+      ? `<${tagName}${attrList}>${children}</${tagName}>`
+      : `<${tagName}${attrList} />`;
+  }
+  return '';
+}
diff --git a/package-lock.json b/package-lock.json
index 0b201a3..a108611 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,16 +1,17 @@
 {
   "name": "@borgar/simple-xml",
-  "version": "2.2.2",
+  "version": "3.0.0-rc.0",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "@borgar/simple-xml",
-      "version": "2.2.2",
+      "version": "3.0.0-rc.0",
       "license": "MIT",
       "devDependencies": {
         "@borgar/eslint-config": "~4.0.1",
         "@eslint/js": "~9.38.0",
+        "@types/node": "~25.5.0",
         "concat-md": "~0.5.1",
         "eslint": "~9.38.0",
         "jsdoc": "~4.0.5",
@@ -1383,6 +1384,16 @@
       "dev": true,
       "license": "MIT"
     },
+    "node_modules/@types/node": {
+      "version": "25.5.0",
+      "resolved": "https://registry.npmjs.org/@types/node/-/node-25.5.0.tgz",
+      "integrity": "sha512-jp2P3tQMSxWugkCUKLRPVUpGaL5MVFwF8RDuSRztfwgN1wmqJeMSbKlnEtQqU8UrhTmzEmZdu2I6v2dpp7XIxw==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "undici-types": "~7.18.0"
+      }
+    },
     "node_modules/@types/normalize-package-data": {
       "version": "2.4.4",
       "resolved": "https://registry.npmjs.org/@types/normalize-package-data/-/normalize-package-data-2.4.4.tgz",
@@ -7069,6 +7080,13 @@
       "integrity": "sha512-+A5Sja4HP1M08MaXya7p5LvjuM7K6q/2EaC0+iovj/wOcMsTzMvDFbasi/oSapiwOlt252IqsKqPjCl7huKS0A==",
       "dev": true
     },
+    "node_modules/undici-types": {
+      "version": "7.18.2",
+      "resolved": "https://registry.npmjs.org/undici-types/-/undici-types-7.18.2.tgz",
+      "integrity": "sha512-AsuCzffGHJybSaRrmr5eHr81mwJU3kjw6M+uprWvCXiNeN9SOGwQ3Jn8jb8m3Z6izVgknn1R0FTCEAP2QrLY/w==",
+      "dev": true,
+      "license": "MIT"
+    },
     "node_modules/unified": {
       "version": "9.2.2",
       "resolved": "https://registry.npmjs.org/unified/-/unified-9.2.2.tgz",
diff --git a/package.json b/package.json
index ff68e93..63688f4 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@borgar/simple-xml",
-  "version": "2.2.2",
+  "version": "3.0.0-rc.0",
   "description": "A reasonably fast, simple and pure-JS XML parser with no dependencies",
   "type": "module",
   "source": "lib/index.ts",
@@ -55,6 +55,7 @@
   "devDependencies": {
     "@borgar/eslint-config": "~4.0.1",
     "@eslint/js": "~9.38.0",
+    "@types/node": "~25.5.0",
     "concat-md": "~0.5.1",
     "eslint": "~9.38.0",
     "jsdoc": "~4.0.5",
diff --git a/test/domQuery-dedup.spec.ts b/test/domQuery-dedup.spec.ts
index ff5caec..d2b1503 100644
--- a/test/domQuery-dedup.spec.ts
+++ b/test/domQuery-dedup.spec.ts
@@ -5,7 +5,7 @@ describe('domQuery dedup fix', () => {
   it('preserves document order for single-group selectors', () => {
     const doc = parseXML('<root><x/><y/><z/></root>');
     const result = doc.root!.querySelectorAll('*');
-    expect(result.map(e => e.tagName)).toEqual(['x', 'y', 'z']);
+    expect(result.map(e => e.tagName)).toEqual([ 'x', 'y', 'z' ]);
   });
 
   it('preserves document order for multi-group (comma) selectors', () => {
@@ -13,7 +13,7 @@ describe('domQuery dedup fix', () => {
     // Even if groups are listed out of document order, results should
     // be in document order (via the getElementsByTagName tree walk).
     const result = doc.root!.querySelectorAll('c, a');
-    expect(result.map(e => e.tagName)).toEqual(['a', 'c']);
+    expect(result.map(e => e.tagName)).toEqual([ 'a', 'c' ]);
   });
 
   it('deduplicates descendant combinator results', () => {
@@ -21,7 +21,7 @@ describe('domQuery dedup fix', () => {
     const doc = parseXML('<root><a><a><c/></a></a></root>');
     // "a c" matches <c> through both <a>'s; should find exactly one <c>
     const result = doc.root!.querySelectorAll('a c');
-    expect(result.map(e => e.tagName)).toEqual(['c']);
+    expect(result.map(e => e.tagName)).toEqual([ 'c' ]);
   });
 
   it('deduplicates multi-group (comma) selector results', () => {
diff --git a/test/namespaces.spec.ts b/test/namespaces.spec.ts
new file mode 100644
index 0000000..edf0370
--- /dev/null
+++ b/test/namespaces.spec.ts
@@ -0,0 +1,44 @@
+import { describe, it, expect } from 'vitest';
+import { parseXML } from '../lib/index.ts';
+
+const ooxml = `
+<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+
+<styleSheet
+  mc:Ignorable="x14ac"
+  xmlns="http://schemas.openxmlformats.org/spreadsheetml/2006/main"
+  xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+  xmlns:x14ac="http://schemas.microsoft.com/office/spreadsheetml/2009/9/ac"
+>
+  <font x14ac:knownFont="1">
+    <name val="Aptos Narrow"/>
+  </font>
+
+  <extLst>
+    <ext xmlns:x14="http://schemas.microsoft.com/office/spreadsheetml/2009/9/main">
+      <x14:slicerStyles defaultSlicerStyle="SlicerStyleLight1"/>
+    </ext>
+    <ext xmlns:x15="http://schemas.microsoft.com/office/spreadsheetml/2010/11/main">
+      <x15:timelineStyles defaultTimelineStyle="TimeSlicerStyleLight1"/>
+    </ext>
+  </extLst>
+</styleSheet>
+`;
+
+describe('namespace validation', () => {
+  it('simple tag', () => {
+    const doc = parseXML(ooxml, { ns: true });
+    expect(doc.namespaces.list()).toStrictEqual([
+      [ 'http://schemas.openxmlformats.org/spreadsheetml/2006/main', '' ],
+      [ 'http://schemas.openxmlformats.org/markup-compatibility/2006', 'mc' ],
+      [ 'http://schemas.microsoft.com/office/spreadsheetml/2009/9/ac', 'x14ac' ],
+      [ 'http://schemas.microsoft.com/office/spreadsheetml/2009/9/main', 'x14' ],
+      [ 'http://schemas.microsoft.com/office/spreadsheetml/2010/11/main', 'x15' ]
+    ]);
+  });
+});
+
+// test:
+// - missing decl
+// - decl collisions (reused prefix)
+// - decl collisions (reused uri)
diff --git a/test/parse-data.spec.ts b/test/parse-data.spec.ts
index d21256f..fa7505c 100644
--- a/test/parse-data.spec.ts
+++ b/test/parse-data.spec.ts
@@ -1,4 +1,5 @@
-/* eslint-disable quotes, quote-props, indent */
+/* eslint-disable @typescript-eslint/no-unsafe-call */
+/* eslint-disable @typescript-eslint/no-unsafe-assignment */
 import { describe, it, expect } from 'vitest';
 import fs from 'fs';
 import { parseXML } from '../lib/index.js';
@@ -23,20 +24,20 @@ describe('parse-data', () => {
   it('whitespace.xml', () => {
     const fileName = 'test/data/whitespace.xml';
     const expected = [
-      "node",
-      [ "a",
-        { "xml:space": "preserve" },
-        " ",
-        [ "b", " ", [ "c", " c " ],  " b " ],
-        " " ],
-      [ "a",
-        { "xml:space": "default" },
-        [ "b", [ "c", " c " ], " b " ] ]
+      'node',
+      [ 'a',
+        { 'xml:space': 'preserve' },
+        ' ',
+        [ 'b', ' ', [ 'c', ' c ' ],  ' b ' ],
+        ' ' ],
+      [ 'a',
+        { 'xml:space': 'default' },
+        [ 'b', [ 'c', ' c ' ], ' b ' ] ]
     ];
     const src = fs.readFileSync(fileName, 'utf8');
     const dom = parseXML(src);
     expect(dom.toJS()).toEqual(expected);
-    expect(dom.root.textContent).toBe("   c  b   c  b ");
+    expect(dom.root!.textContent).toBe('   c  b   c  b ');
   });
 
   it('refs.xml', () => {
@@ -88,24 +89,24 @@ describe('parse-data', () => {
   it('truncation.xml', () => {
     const fileName = 'test/data/truncation.xml';
     const expected = [
-      "mesh",
-      { "name": "mesh_root" },
-      "\n\tsome text\n\tsomeothertext\n\tsome more text\n\t",
-      [ "node",
-        { "attr1": "value1",
-          "attr2": "value2" } ],
-      [ "node",
-        { "attr1": "value2" },
-        [ "汉语",
-          { "名字": "name",
-            "价值": "value" },
-          "世界有很多语言𤭢" ],
-        [ "innernode" ] ],
-      [ "氏名",
-        [ "氏",
-          "山田" ],
-        [ "名",
-          "太郎" ] ]
+      'mesh',
+      { name: 'mesh_root' },
+      '\n\tsome text\n\tsomeothertext\n\tsome more text\n\t',
+      [ 'node',
+        { attr1: 'value1',
+          attr2: 'value2' } ],
+      [ 'node',
+        { attr1: 'value2' },
+        [ '汉语',
+          { 名字: 'name',
+            价值: 'value' },
+          '世界有很多语言𤭢' ],
+        [ 'innernode' ] ],
+      [ '氏名',
+        [ '氏',
+          '山田' ],
+        [ '名',
+          '太郎' ] ]
     ];
     const src = fs.readFileSync(fileName, 'utf8');
     const dom = parseXML(src);
@@ -127,112 +128,112 @@ describe('parse-data', () => {
 
   it('utftest_utf8.xml', () => {
     const fileName = 'test/data/utftest_utf8.xml';
-    const expected = [ "週報",
-    [ "English",
-      { "name": "name",
-        "value": "value" },
-      "The world has many languages" ],
-    [ "Russian",
-      { "name": "название(имя)",
-        "value": "ценность" },
-      "Мир имеет много языков" ],
-    [ "Spanish",
-      { "name": "el nombre",
-        "value": "el valor" },
-      "el mundo tiene muchos idiomas" ],
-    [ "SimplifiedChinese",
-      { "name": "名字",
-        "value": "价值" },
-      "世界有很多语言" ],
-    [ "Русский",
-      { "название": "name",
-        "ценность": "value" },
-      "<имеет>" ],
-    [ "汉语",
-      { "名字": "name",
-        "价值": "value" },
-      "世界有很多语言𤭢" ],
-    [ "Heavy",
-      "\"Mëtæl!\"" ],
-    [ "ä",
-      "Umlaut Element" ],
-    [ "年月週",
-      [ "年度",
-        "1997" ],
-      [ "月度",
-        "1" ],
-      [ "週",
-        "1" ] ],
-    [ "氏名",
-      [ "氏",
-        "山田" ],
-      [ "名",
-        "太郎" ] ],
-    [ "業務報告リスト",
-      [ "業務報告",
-        [ "業務名",
-          "XMLエディターの作成" ],
-        [ "業務コード",
-          "X3355-23" ],
-        [ "工数管理",
-          [ "見積もり工数",
-            "1600" ],
-          [ "実績工数",
-            "320" ],
-          [ "当月見積もり工数",
-            "160" ],
-          [ "当月実績工数",
-            "24" ] ],
-        [ "予定項目リスト",
-          [ "予定項目",
-            [ "P",
-              "XMLエディターの基本仕様の作成" ] ] ],
-        [ "実施事項リスト",
-          [ "実施事項",
-            [ "P",
-              "XMLエディターの基本仕様の作成" ] ],
-          [ "実施事項",
-            [ "P",
-              "競合他社製品の機能調査" ] ] ],
-        [ "上長への要請事項リスト",
-          [ "上長への要請事項",
-            [ "P",
-              "特になし" ] ] ],
-        [ "問題点対策",
-          [ "P",
-            "XMLとは何かわからない。" ] ] ],
-      [ "業務報告",
-        [ "業務名",
-          "検索エンジンの開発" ],
-        [ "業務コード",
-          "S8821-76" ],
-        [ "工数管理",
-          [ "見積もり工数",
-            "120" ],
-          [ "実績工数",
-            "6" ],
-          [ "当月見積もり工数",
-            "32" ],
-          [ "当月実績工数",
-            "2" ] ],
-        [ "予定項目リスト",
-          [ "予定項目",
-            [ "P",
-              [ "A",
-                { "href": "http://www.goo.ne.jp" },
-                "goo" ],
-              "の機能を調べてみる" ] ] ],
-        [ "実施事項リスト",
-          [ "実施事項",
-            [ "P",
-              "更に、どういう検索エンジンがあるか調査する" ] ] ],
-        [ "上長への要請事項リスト",
-          [ "上長への要請事項",
-            [ "P",
-              "開発をするのはめんどうなので、Yahoo!を買収して下さい。" ] ] ],
-        [ "問題点対策",
-          [ "P",
-            "検索エンジンで車を走らせることができない。（要調査）" ] ] ] ] ];
+    const expected = [ '週報',
+      [ 'English',
+        { name: 'name',
+          value: 'value' },
+        'The world has many languages' ],
+      [ 'Russian',
+        { name: 'название(имя)',
+          value: 'ценность' },
+        'Мир имеет много языков' ],
+      [ 'Spanish',
+        { name: 'el nombre',
+          value: 'el valor' },
+        'el mundo tiene muchos idiomas' ],
+      [ 'SimplifiedChinese',
+        { name: '名字',
+          value: '价值' },
+        '世界有很多语言' ],
+      [ 'Русский',
+        { название: 'name',
+          ценность: 'value' },
+        '<имеет>' ],
+      [ '汉语',
+        { 名字: 'name',
+          价值: 'value' },
+        '世界有很多语言𤭢' ],
+      [ 'Heavy',
+        '"Mëtæl!"' ],
+      [ 'ä',
+        'Umlaut Element' ],
+      [ '年月週',
+        [ '年度',
+          '1997' ],
+        [ '月度',
+          '1' ],
+        [ '週',
+          '1' ] ],
+      [ '氏名',
+        [ '氏',
+          '山田' ],
+        [ '名',
+          '太郎' ] ],
+      [ '業務報告リスト',
+        [ '業務報告',
+          [ '業務名',
+            'XMLエディターの作成' ],
+          [ '業務コード',
+            'X3355-23' ],
+          [ '工数管理',
+            [ '見積もり工数',
+              '1600' ],
+            [ '実績工数',
+              '320' ],
+            [ '当月見積もり工数',
+              '160' ],
+            [ '当月実績工数',
+              '24' ] ],
+          [ '予定項目リスト',
+            [ '予定項目',
+              [ 'P',
+                'XMLエディターの基本仕様の作成' ] ] ],
+          [ '実施事項リスト',
+            [ '実施事項',
+              [ 'P',
+                'XMLエディターの基本仕様の作成' ] ],
+            [ '実施事項',
+              [ 'P',
+                '競合他社製品の機能調査' ] ] ],
+          [ '上長への要請事項リスト',
+            [ '上長への要請事項',
+              [ 'P',
+                '特になし' ] ] ],
+          [ '問題点対策',
+            [ 'P',
+              'XMLとは何かわからない。' ] ] ],
+        [ '業務報告',
+          [ '業務名',
+            '検索エンジンの開発' ],
+          [ '業務コード',
+            'S8821-76' ],
+          [ '工数管理',
+            [ '見積もり工数',
+              '120' ],
+            [ '実績工数',
+              '6' ],
+            [ '当月見積もり工数',
+              '32' ],
+            [ '当月実績工数',
+              '2' ] ],
+          [ '予定項目リスト',
+            [ '予定項目',
+              [ 'P',
+                [ 'A',
+                  { href: 'http://www.goo.ne.jp' },
+                  'goo' ],
+                'の機能を調べてみる' ] ] ],
+          [ '実施事項リスト',
+            [ '実施事項',
+              [ 'P',
+                '更に、どういう検索エンジンがあるか調査する' ] ] ],
+          [ '上長への要請事項リスト',
+            [ '上長への要請事項',
+              [ 'P',
+                '開発をするのはめんどうなので、Yahoo!を買収して下さい。' ] ] ],
+          [ '問題点対策',
+            [ 'P',
+              '検索エンジンで車を走らせることができない。（要調査）' ] ] ] ] ];
 
     const src = fs.readFileSync(fileName, 'utf8');
     const dom = parseXML(src);
@@ -241,112 +242,112 @@ describe('parse-data', () => {
 
   it('utftest_utf8_bom.xml', () => {
     const fileName = 'test/data/utftest_utf8_bom.xml';
-    const expected = [ "週報",
-    [ "English",
-      { "name": "name",
-        "value": "value" },
-      "The world has many languages" ],
-    [ "Russian",
-      { "name": "название(имя)",
-        "value": "ценность" },
-      "Мир имеет много языков" ],
-    [ "Spanish",
-      { "name": "el nombre",
-        "value": "el valor" },
-      "el mundo tiene muchos idiomas" ],
-    [ "SimplifiedChinese",
-      { "name": "名字",
-        "value": "价值" },
-      "世界有很多语言" ],
-    [ "Русский",
-      { "название": "name",
-        "ценность": "value" },
-      "<имеет>" ],
-    [ "汉语",
-      { "名字": "name",
-        "价值": "value" },
-      "世界有很多语言𤭢" ],
-    [ "Heavy",
-      "\"Mëtæl!\"" ],
-    [ "ä",
-      "Umlaut Element" ],
-    [ "年月週",
-      [ "年度",
-        "1997" ],
-      [ "月度",
-        "1" ],
-      [ "週",
-        "1" ] ],
-    [ "氏名",
-      [ "氏",
-        "山田" ],
-      [ "名",
-        "太郎" ] ],
-    [ "業務報告リスト",
-      [ "業務報告",
-        [ "業務名",
-          "XMLエディターの作成" ],
-        [ "業務コード",
-          "X3355-23" ],
-        [ "工数管理",
-          [ "見積もり工数",
-            "1600" ],
-          [ "実績工数",
-            "320" ],
-          [ "当月見積もり工数",
-            "160" ],
-          [ "当月実績工数",
-            "24" ] ],
-        [ "予定項目リスト",
-          [ "予定項目",
-            [ "P",
-              "XMLエディターの基本仕様の作成" ] ] ],
-        [ "実施事項リスト",
-          [ "実施事項",
-            [ "P",
-              "XMLエディターの基本仕様の作成" ] ],
-          [ "実施事項",
-            [ "P",
-              "競合他社製品の機能調査" ] ] ],
-        [ "上長への要請事項リスト",
-          [ "上長への要請事項",
-            [ "P",
-              "特になし" ] ] ],
-        [ "問題点対策",
-          [ "P",
-            "XMLとは何かわからない。" ] ] ],
-      [ "業務報告",
-        [ "業務名",
-          "検索エンジンの開発" ],
-        [ "業務コード",
-          "S8821-76" ],
-        [ "工数管理",
-          [ "見積もり工数",
-            "120" ],
-          [ "実績工数",
-            "6" ],
-          [ "当月見積もり工数",
-            "32" ],
-          [ "当月実績工数",
-            "2" ] ],
-        [ "予定項目リスト",
-          [ "予定項目",
-            [ "P",
-              [ "A",
-                { "href": "http://www.goo.ne.jp" },
-                "goo" ],
-              "の機能を調べてみる" ] ] ],
-        [ "実施事項リスト",
-          [ "実施事項",
-            [ "P",
-              "更に、どういう検索エンジンがあるか調査する" ] ] ],
-        [ "上長への要請事項リスト",
-          [ "上長への要請事項",
-            [ "P",
-              "開発をするのはめんどうなので、Yahoo!を買収して下さい。" ] ] ],
-        [ "問題点対策",
-          [ "P",
-            "検索エンジンで車を走らせることができない。（要調査）" ] ] ] ] ];
+    const expected = [ '週報',
+      [ 'English',
+        { name: 'name',
+          value: 'value' },
+        'The world has many languages' ],
+      [ 'Russian',
+        { name: 'название(имя)',
+          value: 'ценность' },
+        'Мир имеет много языков' ],
+      [ 'Spanish',
+        { name: 'el nombre',
+          value: 'el valor' },
+        'el mundo tiene muchos idiomas' ],
+      [ 'SimplifiedChinese',
+        { name: '名字',
+          value: '价值' },
+        '世界有很多语言' ],
+      [ 'Русский',
+        { название: 'name',
+          ценность: 'value' },
+        '<имеет>' ],
+      [ '汉语',
+        { 名字: 'name',
+          价值: 'value' },
+        '世界有很多语言𤭢' ],
+      [ 'Heavy',
+        '"Mëtæl!"' ],
+      [ 'ä',
+        'Umlaut Element' ],
+      [ '年月週',
+        [ '年度',
+          '1997' ],
+        [ '月度',
+          '1' ],
+        [ '週',
+          '1' ] ],
+      [ '氏名',
+        [ '氏',
+          '山田' ],
+        [ '名',
+          '太郎' ] ],
+      [ '業務報告リスト',
+        [ '業務報告',
+          [ '業務名',
+            'XMLエディターの作成' ],
+          [ '業務コード',
+            'X3355-23' ],
+          [ '工数管理',
+            [ '見積もり工数',
+              '1600' ],
+            [ '実績工数',
+              '320' ],
+            [ '当月見積もり工数',
+              '160' ],
+            [ '当月実績工数',
+              '24' ] ],
+          [ '予定項目リスト',
+            [ '予定項目',
+              [ 'P',
+                'XMLエディターの基本仕様の作成' ] ] ],
+          [ '実施事項リスト',
+            [ '実施事項',
+              [ 'P',
+                'XMLエディターの基本仕様の作成' ] ],
+            [ '実施事項',
+              [ 'P',
+                '競合他社製品の機能調査' ] ] ],
+          [ '上長への要請事項リスト',
+            [ '上長への要請事項',
+              [ 'P',
+                '特になし' ] ] ],
+          [ '問題点対策',
+            [ 'P',
+              'XMLとは何かわからない。' ] ] ],
+        [ '業務報告',
+          [ '業務名',
+            '検索エンジンの開発' ],
+          [ '業務コード',
+            'S8821-76' ],
+          [ '工数管理',
+            [ '見積もり工数',
+              '120' ],
+            [ '実績工数',
+              '6' ],
+            [ '当月見積もり工数',
+              '32' ],
+            [ '当月実績工数',
+              '2' ] ],
+          [ '予定項目リスト',
+            [ '予定項目',
+              [ 'P',
+                [ 'A',
+                  { href: 'http://www.goo.ne.jp' },
+                  'goo' ],
+                'の機能を調べてみる' ] ] ],
+          [ '実施事項リスト',
+            [ '実施事項',
+              [ 'P',
+                '更に、どういう検索エンジンがあるか調査する' ] ] ],
+          [ '上長への要請事項リスト',
+            [ '上長への要請事項',
+              [ 'P',
+                '開発をするのはめんどうなので、Yahoo!を買収して下さい。' ] ] ],
+          [ '問題点対策',
+            [ 'P',
+              '検索エンジンで車を走らせることができない。（要調査）' ] ] ] ] ];
     const src = fs.readFileSync(fileName, 'utf8');
     const dom = parseXML(src);
     expect(dom.toJS()).toEqual(expected);
@@ -354,112 +355,112 @@ describe('parse-data', () => {
 
   it('utftest_utf8_clean.xml', () => {
     const fileName = 'test/data/utftest_utf8_clean.xml';
-    const expected = [ "週報",
-    [ "English",
-      { "name": "name",
-        "value": "value" },
-      "The world has many languages" ],
-    [ "Russian",
-      { "name": "название(имя)",
-        "value": "ценность" },
-      "Мир имеет много языков" ],
-    [ "Spanish",
-      { "name": "el nombre",
-        "value": "el valor" },
-      "el mundo tiene muchos idiomas" ],
-    [ "SimplifiedChinese",
-      { "name": "名字",
-        "value": "价值" },
-      "世界有很多语言" ],
-    [ "Русский",
-      { "название": "name",
-        "ценность": "value" },
-      "<имеет>" ],
-    [ "汉语",
-      { "名字": "name",
-        "价值": "value" },
-      "世界有很多语言𤭢" ],
-    [ "Heavy",
-      "quot;Mëtæl!quot;" ],
-    [ "ä",
-      "Umlaut Element" ],
-    [ "年月週",
-      [ "年度",
-        "1997" ],
-      [ "月度",
-        "1" ],
-      [ "週",
-        "1" ] ],
-    [ "氏名",
-      [ "氏",
-        "山田" ],
-      [ "名",
-        "太郎" ] ],
-    [ "業務報告リスト",
-      [ "業務報告",
-        [ "業務名",
-          "XMLエディターの作成" ],
-        [ "業務コード",
-          "X3355-23" ],
-        [ "工数管理",
-          [ "見積もり工数",
-            "1600" ],
-          [ "実績工数",
-            "320" ],
-          [ "当月見積もり工数",
-            "160" ],
-          [ "当月実績工数",
-            "24" ] ],
-        [ "予定項目リスト",
-          [ "予定項目",
-            [ "P",
-              "XMLエディターの基本仕様の作成" ] ] ],
-        [ "実施事項リスト",
-          [ "実施事項",
-            [ "P",
-              "XMLエディターの基本仕様の作成" ] ],
-          [ "実施事項",
-            [ "P",
-              "競合他社製品の機能調査" ] ] ],
-        [ "上長への要請事項リスト",
-          [ "上長への要請事項",
-            [ "P",
-              "特になし" ] ] ],
-        [ "問題点対策",
-          [ "P",
-            "XMLとは何かわからない。" ] ] ],
-      [ "業務報告",
-        [ "業務名",
-          "検索エンジンの開発" ],
-        [ "業務コード",
-          "S8821-76" ],
-        [ "工数管理",
-          [ "見積もり工数",
-            "120" ],
-          [ "実績工数",
-            "6" ],
-          [ "当月見積もり工数",
-            "32" ],
-          [ "当月実績工数",
-            "2" ] ],
-        [ "予定項目リスト",
-          [ "予定項目",
-            [ "P",
-              [ "A",
-                { "href": "http://www.goo.ne.jp" },
-                "goo" ],
-              "の機能を調べてみる" ] ] ],
-        [ "実施事項リスト",
-          [ "実施事項",
-            [ "P",
-              "更に、どういう検索エンジンがあるか調査する" ] ] ],
-        [ "上長への要請事項リスト",
-          [ "上長への要請事項",
-            [ "P",
-              "開発をするのはめんどうなので、Yahoo!を買収して下さい。" ] ] ],
-        [ "問題点対策",
-          [ "P",
-            "検索エンジンで車を走らせることができない。（要調査）" ] ] ] ] ];
+    const expected = [ '週報',
+      [ 'English',
+        { name: 'name',
+          value: 'value' },
+        'The world has many languages' ],
+      [ 'Russian',
+        { name: 'название(имя)',
+          value: 'ценность' },
+        'Мир имеет много языков' ],
+      [ 'Spanish',
+        { name: 'el nombre',
+          value: 'el valor' },
+        'el mundo tiene muchos idiomas' ],
+      [ 'SimplifiedChinese',
+        { name: '名字',
+          value: '价值' },
+        '世界有很多语言' ],
+      [ 'Русский',
+        { название: 'name',
+          ценность: 'value' },
+        '<имеет>' ],
+      [ '汉语',
+        { 名字: 'name',
+          价值: 'value' },
+        '世界有很多语言𤭢' ],
+      [ 'Heavy',
+        'quot;Mëtæl!quot;' ],
+      [ 'ä',
+        'Umlaut Element' ],
+      [ '年月週',
+        [ '年度',
+          '1997' ],
+        [ '月度',
+          '1' ],
+        [ '週',
+          '1' ] ],
+      [ '氏名',
+        [ '氏',
+          '山田' ],
+        [ '名',
+          '太郎' ] ],
+      [ '業務報告リスト',
+        [ '業務報告',
+          [ '業務名',
+            'XMLエディターの作成' ],
+          [ '業務コード',
+            'X3355-23' ],
+          [ '工数管理',
+            [ '見積もり工数',
+              '1600' ],
+            [ '実績工数',
+              '320' ],
+            [ '当月見積もり工数',
+              '160' ],
+            [ '当月実績工数',
+              '24' ] ],
+          [ '予定項目リスト',
+            [ '予定項目',
+              [ 'P',
+                'XMLエディターの基本仕様の作成' ] ] ],
+          [ '実施事項リスト',
+            [ '実施事項',
+              [ 'P',
+                'XMLエディターの基本仕様の作成' ] ],
+            [ '実施事項',
+              [ 'P',
+                '競合他社製品の機能調査' ] ] ],
+          [ '上長への要請事項リスト',
+            [ '上長への要請事項',
+              [ 'P',
+                '特になし' ] ] ],
+          [ '問題点対策',
+            [ 'P',
+              'XMLとは何かわからない。' ] ] ],
+        [ '業務報告',
+          [ '業務名',
+            '検索エンジンの開発' ],
+          [ '業務コード',
+            'S8821-76' ],
+          [ '工数管理',
+            [ '見積もり工数',
+              '120' ],
+            [ '実績工数',
+              '6' ],
+            [ '当月見積もり工数',
+              '32' ],
+            [ '当月実績工数',
+              '2' ] ],
+          [ '予定項目リスト',
+            [ '予定項目',
+              [ 'P',
+                [ 'A',
+                  { href: 'http://www.goo.ne.jp' },
+                  'goo' ],
+                'の機能を調べてみる' ] ] ],
+          [ '実施事項リスト',
+            [ '実施事項',
+              [ 'P',
+                '更に、どういう検索エンジンがあるか調査する' ] ] ],
+          [ '上長への要請事項リスト',
+            [ '上長への要請事項',
+              [ 'P',
+                '開発をするのはめんどうなので、Yahoo!を買収して下さい。' ] ] ],
+          [ '問題点対策',
+            [ 'P',
+              '検索エンジンで車を走らせることができない。（要調査）' ] ] ] ] ];
     const src = fs.readFileSync(fileName, 'utf8');
     const dom = parseXML(src);
     expect(dom.toJS()).toEqual(expected);
@@ -467,112 +468,112 @@ describe('parse-data', () => {
 
   it('utftest_utf8_nodecl.xml', () => {
     const fileName = 'test/data/utftest_utf8_nodecl.xml';
-    const expected = [ "週報",
-    [ "English",
-      { "name": "name",
-        "value": "value" },
-      "The world has many languages" ],
-    [ "Russian",
-      { "name": "название(имя)",
-        "value": "ценность" },
-      "Мир имеет много языков" ],
-    [ "Spanish",
-      { "name": "el nombre",
-        "value": "el valor" },
-      "el mundo tiene muchos idiomas" ],
-    [ "SimplifiedChinese",
-      { "name": "名字",
-        "value": "价值" },
-      "世界有很多语言" ],
-    [ "Русский",
-      { "название": "name",
-        "ценность": "value" },
-      "<имеет>" ],
-    [ "汉语",
-      { "名字": "name",
-        "价值": "value" },
-      "世界有很多语言𤭢" ],
-    [ "Heavy",
-      "\"Mëtæl!\"" ],
-    [ "ä",
-      "Umlaut Element" ],
-    [ "年月週",
-      [ "年度",
-        "1997" ],
-      [ "月度",
-        "1" ],
-      [ "週",
-        "1" ] ],
-    [ "氏名",
-      [ "氏",
-        "山田" ],
-      [ "名",
-        "太郎" ] ],
-    [ "業務報告リスト",
-      [ "業務報告",
-        [ "業務名",
-          "XMLエディターの作成" ],
-        [ "業務コード",
-          "X3355-23" ],
-        [ "工数管理",
-          [ "見積もり工数",
-            "1600" ],
-          [ "実績工数",
-            "320" ],
-          [ "当月見積もり工数",
-            "160" ],
-          [ "当月実績工数",
-            "24" ] ],
-        [ "予定項目リスト",
-          [ "予定項目",
-            [ "P",
-              "XMLエディターの基本仕様の作成" ] ] ],
-        [ "実施事項リスト",
-          [ "実施事項",
-            [ "P",
-              "XMLエディターの基本仕様の作成" ] ],
-          [ "実施事項",
-            [ "P",
-              "競合他社製品の機能調査" ] ] ],
-        [ "上長への要請事項リスト",
-          [ "上長への要請事項",
-            [ "P",
-              "特になし" ] ] ],
-        [ "問題点対策",
-          [ "P",
-            "XMLとは何かわからない。" ] ] ],
-      [ "業務報告",
-        [ "業務名",
-          "検索エンジンの開発" ],
-        [ "業務コード",
-          "S8821-76" ],
-        [ "工数管理",
-          [ "見積もり工数",
-            "120" ],
-          [ "実績工数",
-            "6" ],
-          [ "当月見積もり工数",
-            "32" ],
-          [ "当月実績工数",
-            "2" ] ],
-        [ "予定項目リスト",
-          [ "予定項目",
-            [ "P",
-              [ "A",
-                { "href": "http://www.goo.ne.jp" },
-                "goo" ],
-              "の機能を調べてみる" ] ] ],
-        [ "実施事項リスト",
-          [ "実施事項",
-            [ "P",
-              "更に、どういう検索エンジンがあるか調査する" ] ] ],
-        [ "上長への要請事項リスト",
-          [ "上長への要請事項",
-            [ "P",
-              "開発をするのはめんどうなので、Yahoo!を買収して下さい。" ] ] ],
-        [ "問題点対策",
-          [ "P",
-            "検索エンジンで車を走らせることができない。（要調査）" ] ] ] ] ];
+    const expected = [ '週報',
+      [ 'English',
+        { name: 'name',
+          value: 'value' },
+        'The world has many languages' ],
+      [ 'Russian',
+        { name: 'название(имя)',
+          value: 'ценность' },
+        'Мир имеет много языков' ],
+      [ 'Spanish',
+        { name: 'el nombre',
+          value: 'el valor' },
+        'el mundo tiene muchos idiomas' ],
+      [ 'SimplifiedChinese',
+        { name: '名字',
+          value: '价值' },
+        '世界有很多语言' ],
+      [ 'Русский',
+        { название: 'name',
+          ценность: 'value' },
+        '<имеет>' ],
+      [ '汉语',
+        { 名字: 'name',
+          价值: 'value' },
+        '世界有很多语言𤭢' ],
+      [ 'Heavy',
+        '"Mëtæl!"' ],
+      [ 'ä',
+        'Umlaut Element' ],
+      [ '年月週',
+        [ '年度',
+          '1997' ],
+        [ '月度',
+          '1' ],
+        [ '週',
+          '1' ] ],
+      [ '氏名',
+        [ '氏',
+          '山田' ],
+        [ '名',
+          '太郎' ] ],
+      [ '業務報告リスト',
+        [ '業務報告',
+          [ '業務名',
+            'XMLエディターの作成' ],
+          [ '業務コード',
+            'X3355-23' ],
+          [ '工数管理',
+            [ '見積もり工数',
+              '1600' ],
+            [ '実績工数',
+              '320' ],
+            [ '当月見積もり工数',
+              '160' ],
+            [ '当月実績工数',
+              '24' ] ],
+          [ '予定項目リスト',
+            [ '予定項目',
+              [ 'P',
+                'XMLエディターの基本仕様の作成' ] ] ],
+          [ '実施事項リスト',
+            [ '実施事項',
+              [ 'P',
+                'XMLエディターの基本仕様の作成' ] ],
+            [ '実施事項',
+              [ 'P',
+                '競合他社製品の機能調査' ] ] ],
+          [ '上長への要請事項リスト',
+            [ '上長への要請事項',
+              [ 'P',
+                '特になし' ] ] ],
+          [ '問題点対策',
+            [ 'P',
+              'XMLとは何かわからない。' ] ] ],
+        [ '業務報告',
+          [ '業務名',
+            '検索エンジンの開発' ],
+          [ '業務コード',
+            'S8821-76' ],
+          [ '工数管理',
+            [ '見積もり工数',
+              '120' ],
+            [ '実績工数',
+              '6' ],
+            [ '当月見積もり工数',
+              '32' ],
+            [ '当月実績工数',
+              '2' ] ],
+          [ '予定項目リスト',
+            [ '予定項目',
+              [ 'P',
+                [ 'A',
+                  { href: 'http://www.goo.ne.jp' },
+                  'goo' ],
+                'の機能を調べてみる' ] ] ],
+          [ '実施事項リスト',
+            [ '実施事項',
+              [ 'P',
+                '更に、どういう検索エンジンがあるか調査する' ] ] ],
+          [ '上長への要請事項リスト',
+            [ '上長への要請事項',
+              [ 'P',
+                '開発をするのはめんどうなので、Yahoo!を買収して下さい。' ] ] ],
+          [ '問題点対策',
+            [ 'P',
+              '検索エンジンで車を走らせることができない。（要調査）' ] ] ] ] ];
     const src = fs.readFileSync(fileName, 'utf8');
     const dom = parseXML(src);
     expect(dom.toJS()).toEqual(expected);
diff --git a/test/querySelectorAll.spec.ts b/test/querySelectorAll.spec.ts
index 0a086fc..d1feb27 100644
--- a/test/querySelectorAll.spec.ts
+++ b/test/querySelectorAll.spec.ts
@@ -1,472 +1,474 @@
+/* eslint-disable @typescript-eslint/no-unsafe-call */
+/* eslint-disable @typescript-eslint/no-unsafe-assignment */
 import fs from 'fs';
 import { describe, it, expect } from 'vitest';
 import { parseXML } from '../lib/index.js';
 
 const src = fs.readFileSync('test/data/css-selectors.xml', 'utf8');
-const dom = parseXML(src);
+const domRoot = parseXML(src).root!;
 
 describe('querySelectorAll', () => {
   it('a.url.fn', () => {
-    expect(dom.root.querySelectorAll('a.url.fn').length).toBe(2);
+    expect(domRoot.querySelectorAll('a.url.fn').length).toBe(2);
   });
 
   it('a.url, a.fn', () => {
-    expect(dom.root.querySelectorAll('a.url, a.fn').length).toBe(2);
+    expect(domRoot.querySelectorAll('a.url, a.fn').length).toBe(2);
   });
 
   it('li[class]:nth-of-type(2n+1)', () => {
-    expect(dom.root.querySelectorAll('li[class]:nth-of-type(2n+1)').length).toBe(18);
+    expect(domRoot.querySelectorAll('li[class]:nth-of-type(2n+1)').length).toBe(18);
   });
 
   it('*[class]:nth-of-type(2n+1)', () => {
-    expect(dom.root.querySelectorAll('*[class]:nth-of-type(2n+1)').length).toBe(160);
+    expect(domRoot.querySelectorAll('*[class]:nth-of-type(2n+1)').length).toBe(160);
   });
 
   it('li:nth-of-type(2n+1)', () => {
-    expect(dom.root.querySelectorAll('li:nth-of-type(2n+1)').length).toBe(55);
+    expect(domRoot.querySelectorAll('li:nth-of-type(2n+1)').length).toBe(55);
   });
 
   it('li:nth-of-type(2n+2)', () => {
-    expect(dom.root.querySelectorAll('li:nth-of-type(2n+2)').length).toBe(44);
+    expect(domRoot.querySelectorAll('li:nth-of-type(2n+2)').length).toBe(44);
   });
 
   it('li:nth-of-type(2n+3)', () => {
-    expect(dom.root.querySelectorAll('li:nth-of-type(2n+3)').length).toBe(31);
+    expect(domRoot.querySelectorAll('li:nth-of-type(2n+3)').length).toBe(31);
   });
 
   it('li:nth-of-type(2n+4)', () => {
-    expect(dom.root.querySelectorAll('li:nth-of-type(2n+4)').length).toBe(23);
+    expect(domRoot.querySelectorAll('li:nth-of-type(2n+4)').length).toBe(23);
   });
 
   it('li:nth-last-of-type(2n+1)', () => {
-    expect(dom.root.querySelectorAll('li:nth-last-of-type(2n+1)').length).toBe(55);
+    expect(domRoot.querySelectorAll('li:nth-last-of-type(2n+1)').length).toBe(55);
   });
 
   it('li:nth-last-of-type(2n+2)', () => {
-    expect(dom.root.querySelectorAll('li:nth-last-of-type(2n+2)').length).toBe(44);
+    expect(domRoot.querySelectorAll('li:nth-last-of-type(2n+2)').length).toBe(44);
   });
 
   it('li:nth-last-of-type(2n+3)', () => {
-    expect(dom.root.querySelectorAll('li:nth-last-of-type(2n+3)').length).toBe(31);
+    expect(domRoot.querySelectorAll('li:nth-last-of-type(2n+3)').length).toBe(31);
   });
 
   it('li:nth-last-of-type(2n+4)', () => {
-    expect(dom.root.querySelectorAll('li:nth-last-of-type(2n+4)').length).toBe(23);
+    expect(domRoot.querySelectorAll('li:nth-last-of-type(2n+4)').length).toBe(23);
   });
 
   it('li:nth-of-type(1n)', () => {
-    expect(dom.root.querySelectorAll('li:nth-of-type(1n)').length).toBe(99);
+    expect(domRoot.querySelectorAll('li:nth-of-type(1n)').length).toBe(99);
   });
 
   it('li:nth-of-type(2n)', () => {
-    expect(dom.root.querySelectorAll('li:nth-of-type(2n)').length).toBe(44);
+    expect(domRoot.querySelectorAll('li:nth-of-type(2n)').length).toBe(44);
   });
 
   it('li:nth-of-type(3n)', () => {
-    expect(dom.root.querySelectorAll('li:nth-of-type(3n)').length).toBe(26);
+    expect(domRoot.querySelectorAll('li:nth-of-type(3n)').length).toBe(26);
   });
 
   it('li:nth-of-type(4n)', () => {
-    expect(dom.root.querySelectorAll('li:nth-of-type(4n)').length).toBe(15);
+    expect(domRoot.querySelectorAll('li:nth-of-type(4n)').length).toBe(15);
   });
 
   it('li:nth-last-of-type(1n)', () => {
-    expect(dom.root.querySelectorAll('li:nth-last-of-type(1n)').length).toBe(99);
+    expect(domRoot.querySelectorAll('li:nth-last-of-type(1n)').length).toBe(99);
   });
 
   it('li:nth-last-of-type(2n)', () => {
-    expect(dom.root.querySelectorAll('li:nth-last-of-type(2n)').length).toBe(44);
+    expect(domRoot.querySelectorAll('li:nth-last-of-type(2n)').length).toBe(44);
   });
 
   it('li:nth-last-of-type(3n)', () => {
-    expect(dom.root.querySelectorAll('li:nth-last-of-type(3n)').length).toBe(26);
+    expect(domRoot.querySelectorAll('li:nth-last-of-type(3n)').length).toBe(26);
   });
 
   it('li:nth-last-of-type(4n)', () => {
-    expect(dom.root.querySelectorAll('li:nth-last-of-type(4n)').length).toBe(15);
+    expect(domRoot.querySelectorAll('li:nth-last-of-type(4n)').length).toBe(15);
   });
 
   it('li:nth-of-type(1)', () => {
-    expect(dom.root.querySelectorAll('li:nth-of-type(1)').length).toBe(24);
+    expect(domRoot.querySelectorAll('li:nth-of-type(1)').length).toBe(24);
   });
 
   it('li:nth-of-type(2)', () => {
-    expect(dom.root.querySelectorAll('li:nth-of-type(2)').length).toBe(21);
+    expect(domRoot.querySelectorAll('li:nth-of-type(2)').length).toBe(21);
   });
 
   it('li:nth-of-type(3)', () => {
-    expect(dom.root.querySelectorAll('li:nth-of-type(3)').length).toBe(15);
+    expect(domRoot.querySelectorAll('li:nth-of-type(3)').length).toBe(15);
   });
 
   it('li:nth-of-type(4)', () => {
-    expect(dom.root.querySelectorAll('li:nth-of-type(4)').length).toBe(9);
+    expect(domRoot.querySelectorAll('li:nth-of-type(4)').length).toBe(9);
   });
 
   it('li:nth-last-of-type(1)', () => {
-    expect(dom.root.querySelectorAll('li:nth-last-of-type(1)').length).toBe(24);
+    expect(domRoot.querySelectorAll('li:nth-last-of-type(1)').length).toBe(24);
   });
 
   it('li:nth-last-of-type(2)', () => {
-    expect(dom.root.querySelectorAll('li:nth-last-of-type(2)').length).toBe(21);
+    expect(domRoot.querySelectorAll('li:nth-last-of-type(2)').length).toBe(21);
   });
 
   it('li:nth-last-of-type(3)', () => {
-    expect(dom.root.querySelectorAll('li:nth-last-of-type(3)').length).toBe(15);
+    expect(domRoot.querySelectorAll('li:nth-last-of-type(3)').length).toBe(15);
   });
 
   it('li:nth-last-of-type(4)', () => {
-    expect(dom.root.querySelectorAll('li:nth-last-of-type(4)').length).toBe(9);
+    expect(domRoot.querySelectorAll('li:nth-last-of-type(4)').length).toBe(9);
   });
 
   it('div:nth-child(2n+1)', () => {
-    expect(dom.root.querySelectorAll('div:nth-child(2n+1)').length).toBe(26);
+    expect(domRoot.querySelectorAll('div:nth-child(2n+1)').length).toBe(26);
   });
 
   it('div:nth-child(2n+2)', () => {
-    expect(dom.root.querySelectorAll('div:nth-child(2n+2)').length).toBe(25);
+    expect(domRoot.querySelectorAll('div:nth-child(2n+2)').length).toBe(25);
   });
 
   it('div:nth-child(2n+3)', () => {
-    expect(dom.root.querySelectorAll('div:nth-child(2n+3)').length).toBe(25);
+    expect(domRoot.querySelectorAll('div:nth-child(2n+3)').length).toBe(25);
   });
 
   it('div:nth-child(2n+4)', () => {
-    expect(dom.root.querySelectorAll('div:nth-child(2n+4)').length).toBe(25);
+    expect(domRoot.querySelectorAll('div:nth-child(2n+4)').length).toBe(25);
   });
 
   it('div:nth-last-child(2n+1)', () => {
-    expect(dom.root.querySelectorAll('div:nth-last-child(2n+1)').length).toBe(24);
+    expect(domRoot.querySelectorAll('div:nth-last-child(2n+1)').length).toBe(24);
   });
 
   it('div:nth-last-child(2n+2)', () => {
-    expect(dom.root.querySelectorAll('div:nth-last-child(2n+2)').length).toBe(27);
+    expect(domRoot.querySelectorAll('div:nth-last-child(2n+2)').length).toBe(27);
   });
 
   it('div:nth-last-child(2n+3)', () => {
-    expect(dom.root.querySelectorAll('div:nth-last-child(2n+3)').length).toBe(23);
+    expect(domRoot.querySelectorAll('div:nth-last-child(2n+3)').length).toBe(23);
   });
 
   it('div:nth-last-child(2n+4)', () => {
-    expect(dom.root.querySelectorAll('div:nth-last-child(2n+4)').length).toBe(27);
+    expect(domRoot.querySelectorAll('div:nth-last-child(2n+4)').length).toBe(27);
   });
 
   it('div:nth-child(1n)', () => {
-    expect(dom.root.querySelectorAll('div:nth-child(1n)').length).toBe(51);
+    expect(domRoot.querySelectorAll('div:nth-child(1n)').length).toBe(51);
   });
 
   it('div:nth-child(2n)', () => {
-    expect(dom.root.querySelectorAll('div:nth-child(2n)').length).toBe(25);
+    expect(domRoot.querySelectorAll('div:nth-child(2n)').length).toBe(25);
   });
 
   it('div:nth-child(3n)', () => {
-    expect(dom.root.querySelectorAll('div:nth-child(3n)').length).toBe(18);
+    expect(domRoot.querySelectorAll('div:nth-child(3n)').length).toBe(18);
   });
 
   it('div:nth-child(4n)', () => {
-    expect(dom.root.querySelectorAll('div:nth-child(4n)').length).toBe(15);
+    expect(domRoot.querySelectorAll('div:nth-child(4n)').length).toBe(15);
   });
 
   it('div:nth-last-child(1n)', () => {
-    expect(dom.root.querySelectorAll('div:nth-last-child(1n)').length).toBe(51);
+    expect(domRoot.querySelectorAll('div:nth-last-child(1n)').length).toBe(51);
   });
 
   it('div:nth-last-child(2n)', () => {
-    expect(dom.root.querySelectorAll('div:nth-last-child(2n)').length).toBe(27);
+    expect(domRoot.querySelectorAll('div:nth-last-child(2n)').length).toBe(27);
   });
 
   it('div:nth-last-child(3n)', () => {
-    expect(dom.root.querySelectorAll('div:nth-last-child(3n)').length).toBe(16);
+    expect(domRoot.querySelectorAll('div:nth-last-child(3n)').length).toBe(16);
   });
 
   it('div:nth-last-child(4n)', () => {
-    expect(dom.root.querySelectorAll('div:nth-last-child(4n)').length).toBe(17);
+    expect(domRoot.querySelectorAll('div:nth-last-child(4n)').length).toBe(17);
   });
 
   it('div:nth-child(1)', () => {
-    expect(dom.root.querySelectorAll('div:nth-child(1)').length).toBe(1);
+    expect(domRoot.querySelectorAll('div:nth-child(1)').length).toBe(1);
   });
 
   it('div:nth-child(2)', () => {
-    expect(dom.root.querySelectorAll('div:nth-child(2)').length).toBe(0);
+    expect(domRoot.querySelectorAll('div:nth-child(2)').length).toBe(0);
   });
 
   it('div:nth-child(3)', () => {
-    expect(dom.root.querySelectorAll('div:nth-child(3)').length).toBe(0);
+    expect(domRoot.querySelectorAll('div:nth-child(3)').length).toBe(0);
   });
 
   it('div:nth-child(4)', () => {
-    expect(dom.root.querySelectorAll('div:nth-child(4)').length).toBe(2);
+    expect(domRoot.querySelectorAll('div:nth-child(4)').length).toBe(2);
   });
 
   it('div:nth-last-child(1)', () => {
-    expect(dom.root.querySelectorAll('div:nth-last-child(1)').length).toBe(1);
+    expect(domRoot.querySelectorAll('div:nth-last-child(1)').length).toBe(1);
   });
 
   it('div:nth-last-child(2)', () => {
-    expect(dom.root.querySelectorAll('div:nth-last-child(2)').length).toBe(0);
+    expect(domRoot.querySelectorAll('div:nth-last-child(2)').length).toBe(0);
   });
 
   it('div:nth-last-child(3)', () => {
-    expect(dom.root.querySelectorAll('div:nth-last-child(3)').length).toBe(0);
+    expect(domRoot.querySelectorAll('div:nth-last-child(3)').length).toBe(0);
   });
 
   it('div:nth-last-child(4)', () => {
-    expect(dom.root.querySelectorAll('div:nth-last-child(4)').length).toBe(1);
+    expect(domRoot.querySelectorAll('div:nth-last-child(4)').length).toBe(1);
   });
 
   it('div:nth-child(even)', () => {
-    expect(dom.root.querySelectorAll('div:nth-child(even)').length).toBe(25);
+    expect(domRoot.querySelectorAll('div:nth-child(even)').length).toBe(25);
   });
 
   it('div:nth-child(odd)', () => {
-    expect(dom.root.querySelectorAll('div:nth-child(odd)').length).toBe(26);
+    expect(domRoot.querySelectorAll('div:nth-child(odd)').length).toBe(26);
   });
 
   it('div:nth-child(n)', () => {
-    expect(dom.root.querySelectorAll('div:nth-child(n)').length).toBe(51);
+    expect(domRoot.querySelectorAll('div:nth-child(n)').length).toBe(51);
   });
 
   it('div:nth-last-child(even)', () => {
-    expect(dom.root.querySelectorAll('div:nth-last-child(even)').length).toBe(27);
+    expect(domRoot.querySelectorAll('div:nth-last-child(even)').length).toBe(27);
   });
 
   it('div:nth-last-child(odd)', () => {
-    expect(dom.root.querySelectorAll('div:nth-last-child(odd)').length).toBe(24);
+    expect(domRoot.querySelectorAll('div:nth-last-child(odd)').length).toBe(24);
   });
 
   it('div:nth-last-child(n)', () => {
-    expect(dom.root.querySelectorAll('div:nth-last-child(n)').length).toBe(51);
+    expect(domRoot.querySelectorAll('div:nth-last-child(n)').length).toBe(51);
   });
 
   it('div:first-of-type', () => {
-    expect(dom.root.querySelectorAll('div:first-of-type').length).toBe(3);
+    expect(domRoot.querySelectorAll('div:first-of-type').length).toBe(3);
   });
 
   it('div:last-of-type', () => {
-    expect(dom.root.querySelectorAll('div:last-of-type').length).toBe(3);
+    expect(domRoot.querySelectorAll('div:last-of-type').length).toBe(3);
   });
 
   it('div:only-of-type', () => {
-    expect(dom.root.querySelectorAll('div:only-of-type').length).toBe(2);
+    expect(domRoot.querySelectorAll('div:only-of-type').length).toBe(2);
   });
 
   it('div:nth-of-type(even)', () => {
-    expect(dom.root.querySelectorAll('div:nth-of-type(even)').length).toBe(24);
+    expect(domRoot.querySelectorAll('div:nth-of-type(even)').length).toBe(24);
   });
 
   it('div:nth-of-type(2n)', () => {
-    expect(dom.root.querySelectorAll('div:nth-of-type(2n)').length).toBe(24);
+    expect(domRoot.querySelectorAll('div:nth-of-type(2n)').length).toBe(24);
   });
 
   it('div:nth-of-type(odd)', () => {
-    expect(dom.root.querySelectorAll('div:nth-of-type(odd)').length).toBe(27);
+    expect(domRoot.querySelectorAll('div:nth-of-type(odd)').length).toBe(27);
   });
 
   it('div:nth-of-type(2n+1)', () => {
-    expect(dom.root.querySelectorAll('div:nth-of-type(2n+1)').length).toBe(27);
+    expect(domRoot.querySelectorAll('div:nth-of-type(2n+1)').length).toBe(27);
   });
 
   it('div:nth-of-type(n)', () => {
-    expect(dom.root.querySelectorAll('div:nth-of-type(n)').length).toBe(51);
+    expect(domRoot.querySelectorAll('div:nth-of-type(n)').length).toBe(51);
   });
 
   it('div:nth-last-of-type(even)', () => {
-    expect(dom.root.querySelectorAll('div:nth-last-of-type(even)').length).toBe(24);
+    expect(domRoot.querySelectorAll('div:nth-last-of-type(even)').length).toBe(24);
   });
 
   it('div:nth-last-of-type(2n)', () => {
-    expect(dom.root.querySelectorAll('div:nth-last-of-type(2n)').length).toBe(24);
+    expect(domRoot.querySelectorAll('div:nth-last-of-type(2n)').length).toBe(24);
   });
 
   it('div:nth-last-of-type(odd)', () => {
-    expect(dom.root.querySelectorAll('div:nth-last-of-type(odd)').length).toBe(27);
+    expect(domRoot.querySelectorAll('div:nth-last-of-type(odd)').length).toBe(27);
   });
 
   it('div:nth-last-of-type(2n+1)', () => {
-    expect(dom.root.querySelectorAll('div:nth-last-of-type(2n+1)').length).toBe(27);
+    expect(domRoot.querySelectorAll('div:nth-last-of-type(2n+1)').length).toBe(27);
   });
 
   it('div:nth-last-of-type(n)', () => {
-    expect(dom.root.querySelectorAll('div:nth-last-of-type(n)').length).toBe(51);
+    expect(domRoot.querySelectorAll('div:nth-last-of-type(n)').length).toBe(51);
   });
 
   it('label[for]', () => {
-    expect(dom.root.querySelectorAll('label[for]').length).toBe(0);
+    expect(domRoot.querySelectorAll('label[for]').length).toBe(0);
   });
 
   it('*', () => {
-    expect(dom.root.querySelectorAll('*').length).toBe(1778);
+    expect(domRoot.querySelectorAll('*').length).toBe(1778);
   });
 
   it('body', () => {
-    expect(dom.root.querySelectorAll('body').length).toBe(0);
+    expect(domRoot.querySelectorAll('body').length).toBe(0);
   });
 
   it('div', () => {
-    expect(dom.root.querySelectorAll('div').length).toBe(51);
+    expect(domRoot.querySelectorAll('div').length).toBe(51);
   });
 
   it('body div', () => {
-    expect(dom.root.querySelectorAll('body div').length).toBe(0);
+    expect(domRoot.querySelectorAll('body div').length).toBe(0);
   });
 
   it('div div', () => {
-    expect(dom.root.querySelectorAll('div div').length).toBe(2);
+    expect(domRoot.querySelectorAll('div div').length).toBe(2);
   });
 
   it('div div div', () => {
-    expect(dom.root.querySelectorAll('div div div').length).toBe(0);
+    expect(domRoot.querySelectorAll('div div div').length).toBe(0);
   });
 
   it('div p', () => {
-    expect(dom.root.querySelectorAll('div p').length).toBe(140);
+    expect(domRoot.querySelectorAll('div p').length).toBe(140);
   });
 
   it('div > p', () => {
-    expect(dom.root.querySelectorAll('div > p').length).toBe(134);
+    expect(domRoot.querySelectorAll('div > p').length).toBe(134);
   });
 
   it('div + p', () => {
-    expect(dom.root.querySelectorAll('div + p').length).toBe(22);
+    expect(domRoot.querySelectorAll('div + p').length).toBe(22);
   });
 
   it('div ~ p', () => {
-    expect(dom.root.querySelectorAll('div ~ p').length).toBe(183);
+    expect(domRoot.querySelectorAll('div ~ p').length).toBe(183);
   });
 
   it('div.example ~ p', () => {
-    expect(dom.root.querySelectorAll('div.example ~ p').length).toBe(152);
+    expect(domRoot.querySelectorAll('div.example ~ p').length).toBe(152);
   });
 
   it('div[class^=exa][class$=mple]', () => {
-    expect(dom.root.querySelectorAll('div[class^=exa][class$=mple]').length).toBe(43);
+    expect(domRoot.querySelectorAll('div[class^=exa][class$=mple]').length).toBe(43);
   });
 
   it('div p a', () => {
-    expect(dom.root.querySelectorAll('div p a').length).toBe(12);
+    expect(domRoot.querySelectorAll('div p a').length).toBe(12);
   });
 
   it('div, p, a', () => {
-    expect(dom.root.querySelectorAll('div, p, a').length).toBe(671);
+    expect(domRoot.querySelectorAll('div, p, a').length).toBe(671);
   });
 
   it('.note', () => {
-    expect(dom.root.querySelectorAll('.note').length).toBe(14);
+    expect(domRoot.querySelectorAll('.note').length).toBe(14);
   });
 
   it('div.example', () => {
-    expect(dom.root.querySelectorAll('div.example').length).toBe(43);
+    expect(domRoot.querySelectorAll('div.example').length).toBe(43);
   });
 
   it('ul .tocline2', () => {
-    expect(dom.root.querySelectorAll('ul .tocline2').length).toBe(12);
+    expect(domRoot.querySelectorAll('ul .tocline2').length).toBe(12);
   });
 
   it('div.example, div.note', () => {
-    expect(dom.root.querySelectorAll('div.example, div.note').length).toBe(44);
+    expect(domRoot.querySelectorAll('div.example, div.note').length).toBe(44);
   });
 
   it('#title', () => {
-    expect(dom.root.querySelectorAll('#title').length).toBe(1);
+    expect(domRoot.querySelectorAll('#title').length).toBe(1);
   });
 
   it('h1#title', () => {
-    expect(dom.root.querySelectorAll('h1#title').length).toBe(1);
+    expect(domRoot.querySelectorAll('h1#title').length).toBe(1);
   });
 
   it('div #title', () => {
-    expect(dom.root.querySelectorAll('div #title').length).toBe(1);
+    expect(domRoot.querySelectorAll('div #title').length).toBe(1);
   });
 
   it('ul.toc li.tocline2', () => {
-    expect(dom.root.querySelectorAll('ul.toc li.tocline2').length).toBe(12);
+    expect(domRoot.querySelectorAll('ul.toc li.tocline2').length).toBe(12);
   });
 
   it('ul.toc > li.tocline2', () => {
-    expect(dom.root.querySelectorAll('ul.toc > li.tocline2').length).toBe(12);
+    expect(domRoot.querySelectorAll('ul.toc > li.tocline2').length).toBe(12);
   });
 
   it('h1#title + div > p', () => {
-    expect(dom.root.querySelectorAll('h1#title + div > p').length).toBe(0);
+    expect(domRoot.querySelectorAll('h1#title + div > p').length).toBe(0);
   });
 
   it('h1[id]:contains(Selectors)', () => {
-    expect(dom.root.querySelectorAll('h1[id]:contains(Selectors)').length).toBe(1);
+    expect(domRoot.querySelectorAll('h1[id]:contains(Selectors)').length).toBe(1);
   });
 
   it('a[href][lang][class]', () => {
-    expect(dom.root.querySelectorAll('a[href][lang][class]').length).toBe(1);
+    expect(domRoot.querySelectorAll('a[href][lang][class]').length).toBe(1);
   });
 
   it('div[class]', () => {
-    expect(dom.root.querySelectorAll('div[class]').length).toBe(51);
+    expect(domRoot.querySelectorAll('div[class]').length).toBe(51);
   });
 
   it('div[class=example]', () => {
-    expect(dom.root.querySelectorAll('div[class=example]').length).toBe(43);
+    expect(domRoot.querySelectorAll('div[class=example]').length).toBe(43);
   });
 
   it('div[class^=exa]', () => {
-    expect(dom.root.querySelectorAll('div[class^=exa]').length).toBe(43);
+    expect(domRoot.querySelectorAll('div[class^=exa]').length).toBe(43);
   });
 
   it('div[class$=mple]', () => {
-    expect(dom.root.querySelectorAll('div[class$=mple]').length).toBe(43);
+    expect(domRoot.querySelectorAll('div[class$=mple]').length).toBe(43);
   });
 
   it('div[class*=e]', () => {
-    expect(dom.root.querySelectorAll('div[class*=e]').length).toBe(50);
+    expect(domRoot.querySelectorAll('div[class*=e]').length).toBe(50);
   });
 
   it('div[class|=dialog]', () => {
-    expect(dom.root.querySelectorAll('div[class|=dialog]').length).toBe(0);
+    expect(domRoot.querySelectorAll('div[class|=dialog]').length).toBe(0);
   });
 
   it('div[class!=made_up]', () => {
-    expect(dom.root.querySelectorAll('div[class!=made_up]').length).toBe(51);
+    expect(domRoot.querySelectorAll('div[class!=made_up]').length).toBe(51);
   });
 
   it('div[class~=example]', () => {
-    expect(dom.root.querySelectorAll('div[class~=example]').length).toBe(43);
+    expect(domRoot.querySelectorAll('div[class~=example]').length).toBe(43);
   });
 
   it('div:not(.example)', () => {
-    expect(dom.root.querySelectorAll('div:not(.example)').length).toBe(8);
+    expect(domRoot.querySelectorAll('div:not(.example)').length).toBe(8);
   });
 
   it('p:contains(selectors)', () => {
-    expect(dom.root.querySelectorAll('p:contains(selectors)').length).toBe(54);
+    expect(domRoot.querySelectorAll('p:contains(selectors)').length).toBe(54);
   });
 
   it('p:nth-child(even)', () => {
-    expect(dom.root.querySelectorAll('p:nth-child(even)').length).toBe(158);
+    expect(domRoot.querySelectorAll('p:nth-child(even)').length).toBe(158);
   });
 
   it('p:nth-child(2n)', () => {
-    expect(dom.root.querySelectorAll('p:nth-child(2n)').length).toBe(158);
+    expect(domRoot.querySelectorAll('p:nth-child(2n)').length).toBe(158);
   });
 
   it('p:nth-child(odd)', () => {
-    expect(dom.root.querySelectorAll('p:nth-child(odd)').length).toBe(166);
+    expect(domRoot.querySelectorAll('p:nth-child(odd)').length).toBe(166);
   });
 
   it('p:nth-child(2n+1)', () => {
-    expect(dom.root.querySelectorAll('p:nth-child(2n+1)').length).toBe(166);
+    expect(domRoot.querySelectorAll('p:nth-child(2n+1)').length).toBe(166);
   });
 
   it('p:nth-child(n)', () => {
-    expect(dom.root.querySelectorAll('p:nth-child(n)').length).toBe(324);
+    expect(domRoot.querySelectorAll('p:nth-child(n)').length).toBe(324);
   });
 
   it('p:only-child', () => {
-    expect(dom.root.querySelectorAll('p:only-child').length).toBe(3);
+    expect(domRoot.querySelectorAll('p:only-child').length).toBe(3);
   });
 
   it('p:last-child', () => {
-    expect(dom.root.querySelectorAll('p:last-child').length).toBe(19);
+    expect(domRoot.querySelectorAll('p:last-child').length).toBe(19);
   });
 
   it('p:first-child', () => {
-    expect(dom.root.querySelectorAll('p:first-child').length).toBe(54);
+    expect(domRoot.querySelectorAll('p:first-child').length).toBe(54);
   });
 });
diff --git a/tsconfig.json b/tsconfig.json
index 05367b8..025a118 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -1,23 +1,28 @@
 {
-	"include": ["lib/", "eslint.config.js"],
-	"compilerOptions": {
-		"rootDir": ".",
-		"target": "ES2022",
-		"module": "NodeNext",
-		"moduleResolution": "NodeNext",
-		"allowSyntheticDefaultImports": true,
-		"allowImportingTsExtensions": true,
-		"forceConsistentCasingInFileNames": true,
-		"verbatimModuleSyntax": true,
-		"erasableSyntaxOnly": true,
-		"strict": true,
-		"allowJs": true,
-		"checkJs": true,
-		"stripInternal": true,
-		"noEmitOnError": true,
-		"noErrorTruncation": true,
-		"outDir": "types",
-		"declarationMap": false,
-		"skipLibCheck": true
-	}
+  "include": [
+    "lib/",
+    "test/",
+    "eslint.config.js"
+  ],
+  "compilerOptions": {
+    "rootDir": ".",
+    "target": "ES2022",
+    "module": "NodeNext",
+    "moduleResolution": "NodeNext",
+    "allowSyntheticDefaultImports": true,
+    "allowImportingTsExtensions": true,
+    "forceConsistentCasingInFileNames": true,
+    "verbatimModuleSyntax": true,
+    "erasableSyntaxOnly": true,
+    "strict": true,
+    "allowJs": true,
+    "checkJs": true,
+    "noEmit": true,
+    "stripInternal": true,
+    "noEmitOnError": true,
+    "noErrorTruncation": true,
+    "outDir": "types",
+    "declarationMap": false,
+    "skipLibCheck": true
+  }
 }