fix: update document APIs to be readonly

lib/DocumentType.js

@@ -9,12 +9,16 @@ function DocumentType(ownerDocument, name, publicId, systemId) {
   Leaf.call(this);
   this.nodeType = Node.DOCUMENT_TYPE_NODE;
   this.ownerDocument = ownerDocument || null;
-  this.name = name;
+  this._name = name;
   this.publicId = publicId || "";
   this.systemId = systemId || "";
 }
 
 DocumentType.prototype = Object.create(Leaf.prototype, {
+  name: {
+    get: function() { return this._name; },
+    set: function() { /* no-op per spec */ }
+  },
   nodeName: { get: function() { return this.name; }},
   nodeValue: {
     get: function() { return null; },

lib/Element.js

@@ -22,9 +22,9 @@ function Element(doc, localName, namespaceURI, prefix) {
   ContainerNode.call(this);
   this.nodeType = Node.ELEMENT_NODE;
   this.ownerDocument = doc;
-  this.localName = localName;
+  this._localName = localName;
   this.namespaceURI = namespaceURI;
-  this.prefix = prefix;
+  this._prefix = prefix;
   this._tagName = undefined;
 
   // These properties maintain the set of attributes
@@ -44,6 +44,14 @@ function recursiveGetText(node, a) {
 }
 
 Element.prototype = Object.create(ContainerNode.prototype, {
+  localName: {
+    get: function () { return this._localName; },
+    set: function () { /* no-op per spec */ }
+  },
+  prefix: {
+    get: function () { return this._prefix; },
+    set: function () { /* no-op per spec */ }
+  },
   isHTML: { get: function isHTML() {
     return this.namespaceURI === NAMESPACE.HTML && this.ownerDocument.isHTML;
   }},
@@ -66,7 +74,9 @@ Element.prototype = Object.create(ContainerNode.prototype, {
       this._tagName = tn;
     }
     return this._tagName;
-  }},
+    },
+    set: function () { /* no-op per spec */ }
+  },
   nodeName: { get: function() { return this.tagName; }},
   nodeValue: {
     get: function() {
@@ -985,8 +995,8 @@ attributes.registerChangeHandler(Element, 'class',
 function Attr(elt, lname, prefix, namespace, value) {
   // localName and namespace are constant for any attr object.
   // But value may change.  And so can prefix, and so, therefore can name.
-  this.localName = lname;
-  this.prefix = (prefix===null || prefix==='') ? null : ('' + prefix);
+  this._localName = lname;
+  this._prefix = (prefix===null || prefix==='') ? null : ('' + prefix);
   this.namespaceURI = (namespace===null || namespace==='') ? null : ('' + namespace);
   this.data = value;
   // Set ownerElement last to ensure it is hooked up to onchange handler
@@ -995,6 +1005,14 @@ function Attr(elt, lname, prefix, namespace, value) {
 
 // In DOM 3 Attr was supposed to extend Node; in DOM 4 that was abandoned.
 Attr.prototype = Object.create(Object.prototype, {
+  localName: {
+    get: function () { return this._localName; },
+    set: function () { /* no-op per spec */ }
+  },
+  prefix: {
+    get: function () { return this._prefix; },
+    set: function () { /* no-op per spec */ }
+  },
   ownerElement: {
     get: function() { return this._ownerElement; },
   },

lib/ProcessingInstruction.js

@@ -8,7 +8,7 @@ function ProcessingInstruction(doc, target, data) {
   CharacterData.call(this);
   this.nodeType = Node.PROCESSING_INSTRUCTION_NODE;
   this.ownerDocument = doc;
-  this.target = target;
+  this._target = target;
   this._data = data;
 }
 
@@ -22,6 +22,10 @@ var nodeValue = {
 };
 
 ProcessingInstruction.prototype = Object.create(CharacterData.prototype, {
+  target: {
+    get: function () { return this._target; },
+    set: function () { /* no-op per spec */ }
+  },
   nodeName: { get: function() { return this.target; }},
   nodeValue: nodeValue,
   textContent: nodeValue,

test/readonly.js

@@ -0,0 +1,43 @@
+'use strict';
+
+var domino = require('../lib');
+
+exports.readonly = {};
+
+exports.readonly.attr = function () {
+  var doc = domino.createDocument();
+  var attr = doc.createAttribute('test');
+
+  attr.localName = 'foo';
+  attr.localName.should.equal('test');
+
+  attr.prefix = 'foo';
+  (attr.prefix === null).should.be.true();
+};
+
+exports.readonly.element = function () {
+  var doc = domino.createDocument();
+  var el = doc.createElement('div');
+
+  el.localName = 'foo';
+  el.localName.should.equal('div');
+
+  el.prefix = 'foo';
+  (el.prefix === null).should.be.true();
+};
+
+exports.readonly.processingInstruction = function () {
+  var doc = domino.createDocument();
+  var pi = doc.createProcessingInstruction('target', 'data');
+
+  pi.target = 'foo';
+  pi.target.should.equal('target');
+};
+
+exports.readonly.documentType = function () {
+  var doc = domino.createDocument();
+  var dt = doc.implementation.createDocumentType('name', 'public', 'system');
+
+  dt.name = 'foo';
+  dt.name.should.equal('name');
+};