unexpectedjs · Munter · Apr 23, 2015 · Apr 21, 2015 · Apr 23, 2015 · Apr 23, 2015
diff --git a/README.md b/README.md
@@ -68,6 +68,19 @@ expect(node, 'to [only] have attributes', {
 
 **Queried for**
 
+**When parsed as HTML**
+
+Parses the subject (string) as an HTML document using the facilities available in the browser, with a fallback to jsdom, then delegates to the next assertion in the argument list:
+
+```js
+expect(
+    '<html><body><div class="foo"></div></body></html>',
+    'when parsed as HTML',
+    'queried for', 'div',
+    'to have attributes', { class: 'foo' }
+);
+```
+
 
 License
 -------

diff --git a/lib/index.js b/lib/index.js
@@ -422,5 +422,20 @@ module.exports = {
       }
       this.shift(expect, queryResult, 1);
     });
+
+    expect.addAssertion('string', 'when parsed as (html|HTML)', function (expect, subject) {
+      var htmlDocument;
+      if (typeof DOMParser !== 'undefined') {
+        htmlDocument = new DOMParser().parseFromString(subject, 'text/html');
+      } else if (typeof document !== 'undefined' && document.implementation && document.implementation.createHTMLDocument) {
+        htmlDocument = document.implementation.createHTMLDocument('');
+        htmlDocument.open();
+        htmlDocument.write(subject);
+        htmlDocument.close();
+      } else {
+        htmlDocument = require('jsdom').jsdom(subject);
+      }
+      return this.shift(expect, htmlDocument, 0);
+    });
   }
 };
diff --git a/package.json b/package.json
@@ -40,8 +40,10 @@
     "magicpen-prism": "^1.1.1",
     "mocha": "^2.1.0",
     "mocha-lcov-reporter": "0.0.2",
+    "sinon": "1.14.1",
     "uglifyjs": "^2.4.10",
-    "unexpected": "^7.0.1"
+    "unexpected": "^7.0.1",
+    "unexpected-sinon": "5.1.2"
   },
   "dependencies": {
     "array-changes": "1.0.1",

diff --git a/test/unexpected-dom.js b/test/unexpected-dom.js
@@ -1,9 +1,10 @@
-/*global describe, it, beforeEach*/
+/*global describe, it, beforeEach, afterEach*/
 var unexpected = require('unexpected'),
     unexpectedDom = require('../lib/index'),
+    sinon = require('sinon'),
     jsdom = require('jsdom');
 
-var expect = unexpected.clone().installPlugin(unexpectedDom);
+var expect = unexpected.clone().installPlugin(require('unexpected-sinon')).installPlugin(unexpectedDom);
 expect.output.installPlugin(require('magicpen-prism'));
 
 expect.addAssertion('to inspect as [itself]', function (expect, subject, value) {
@@ -491,4 +492,81 @@ describe('unexpected-dom', function () {
         );
     });
   });
+
+  describe('when parsed as HTML', function () {
+    var htmlSrc = '<!DOCTYPE html><html><body class="bar">foo</body></html>';
+    it('should parse a string as a complete HTML document', function () {
+      expect(htmlSrc, 'when parsed as HTML',
+          expect.it('to be a', 'HTMLDocument')
+            .and('to equal', jsdom.jsdom(htmlSrc))
+            .and('queried for first', 'body', 'to have attributes', { class: 'bar' })
+      );
+    });
+
+    describe('when the DOMParser global is available', function () {
+      var originalDOMParser,
+          DOMParserSpy,
+          parseFromStringSpy;
+
+      beforeEach(function () {
+        originalDOMParser = global.DOMParser;
+        global.DOMParser = DOMParserSpy = sinon.spy(function () {
+          return {
+            parseFromString: parseFromStringSpy = sinon.spy(function (htmlString, contentType) {
+              return jsdom.jsdom(htmlString);
+            })
+          };
+        });
+      });
+      afterEach(function () {
+        global.DOMParser = originalDOMParser;
+      });
+
+      it('should use DOMParser to parse the document', function () {
+        expect(htmlSrc, 'when parsed as HTML', 'queried for first', 'body', 'to have text', 'foo');
+        expect(DOMParserSpy, 'was called once');
+        expect(DOMParserSpy, 'was called with');
+        expect(DOMParserSpy.calledWithNew(), 'to be true');
+        expect(parseFromStringSpy, 'was called once');
+        expect(parseFromStringSpy, 'was called with', htmlSrc, 'text/html');
+      });
+    });
+
+    describe('when the document global is available', function () {
+      var originalDocument,
+          createHTMLDocumentSpy,
+          mockDocument;
+
+      beforeEach(function () {
+        originalDocument = global.document;
+        global.document = {
+          implementation: {
+            createHTMLDocument: createHTMLDocumentSpy = sinon.spy(function () {
+              mockDocument = jsdom.jsdom(htmlSrc);
+              mockDocument.open = sinon.spy();
+              mockDocument.write = sinon.spy();
+              mockDocument.close = sinon.spy();
+              return mockDocument;
+            })
+          }
+        };
+      });
+      afterEach(function () {
+        global.document = originalDocument;
+      });
+
+      it('should use document.implementation.createHTMLDocument to parse the document', function () {
+        expect(htmlSrc, 'when parsed as HTML', 'queried for first', 'body', 'to have text', 'foo');
+        expect(createHTMLDocumentSpy, 'was called once');
+        expect(createHTMLDocumentSpy, 'was called with');
+        expect(mockDocument.open, 'was called once');
+        expect(mockDocument.write, 'was called with');
+        expect(mockDocument.write, 'was called once');
+        expect(mockDocument.write, 'was called with', htmlSrc);
+        expect(mockDocument.close, 'was called once');
+        expect(mockDocument.write, 'was called with');
+        expect([mockDocument.open, mockDocument.write, mockDocument.close], 'given call order');
+      });
+    });
+  });
 });