Add: Verify page option (#224)

README.md

@@ -102,6 +102,7 @@ Usage: pa11y [options] <url>
     -p, --port <port>             the port to run PhantomJS on
     -t, --timeout <ms>            the timeout in milliseconds
     -w, --wait <ms>               the time to wait before running tests in milliseconds
+    -v, --verify-page <string>    HTML string to verify is present in the page source HTML
     -d, --debug                   output debug messages
     -H, --htmlcs <url>            the URL or path to source HTML_CodeSniffer from
     -e, --phantomjs <path>        the path to the phantomjs executable
@@ -549,6 +550,18 @@ pa11y({
 
 Defaults to `0`.
 
+### `verifyPage` (string)
+
+HTML string to verify is present in the page source HTML. Could be used to ascertain that intended page is being tested (as opposed to error page) by using `<title>` tags and content (as below), or that a specific element is present.
+
+```js
+pa11y({
+    verifyPage: '<title>Nature Research: science journals, jobs, information and services.</title>'
+});
+```
+
+Defaults to `null`.
+
 
 Examples
 --------
@@ -764,7 +777,7 @@ If you're opening issues related to these, please mention the version that the i
 License
 -------
 
-Pa11y is licensed under the [Lesser General Public License (LGPL-3.0)][info-license].  
+Pa11y is licensed under the [Lesser General Public License (LGPL-3.0)][info-license].<br>
 Copyright &copy; 2016, Springer Nature
 
 

bin/pa11y

@@ -63,6 +63,10 @@ function configureProgram(program) {
 			'-w, --wait <ms>',
 			'the time to wait before running tests in milliseconds'
 		)
+		.option(
+			'-v, --verify-page <string>',
+			'HTML string to verify is present in the page source HTML'
+		)
 		.option(
 			'-d, --debug',
 			'output debug messages'
@@ -123,7 +127,8 @@ function processOptions(program) {
 		rootElement: program.rootElement,
 		standard: program.standard,
 		timeout: program.timeout,
-		wait: program.wait
+		wait: program.wait,
+		verifyPage: program.verifyPage
 	});
 
 	if (!program.debug) {

lib/inject.js

@@ -3,6 +3,13 @@
 /* eslint-disable max-statements */
 function injectPa11y(window, options, done) {
 
+	if (options.verifyPage) {
+		var windowHtml = window.document.documentElement.outerHTML;
+		if (!windowHtml.match(new RegExp(options.verifyPage))) {
+			return reportError('Page not verified - HTML did not contain: "' + options.verifyPage + '"');
+		}
+	}
+
 	var messageTypeMap = {
 		1: 'error',
 		2: 'warning',

lib/pa11y.js

@@ -37,7 +37,8 @@ module.exports.defaults = {
 	rootElement: null,
 	standard: 'WCAG2AA',
 	allowedStandards: ['Section508', 'WCAG2A', 'WCAG2AA', 'WCAG2AAA'],
-	wait: 0
+	wait: 0,
+	verifyPage: null
 };
 
 function pa11y(options) {
@@ -141,7 +142,8 @@ function testPage(browser, page, options, done) {
 				ignore: options.ignore,
 				rootElement: options.rootElement,
 				standard: options.standard,
-				wait: options.wait
+				wait: options.wait,
+				verifyPage: options.verifyPage
 			}, next);
 		}
 

test/unit/lib/inject.js

@@ -541,5 +541,26 @@ describe('lib/inject', function() {
 		});
 	});
 
+	describe('verifyPage flag', function() {
+
+		it('should not error when verifyPage value exists in HTML', function(done) {
+			options.verifyPage = '<title>Foo</title>';
+			inject(window, options, function(result) {
+				assert.isUndefined(result.error);
+				done();
+			});
+		});
+
+		it('should error when verifyPage value does not exist in HTML', function(done) {
+			options.verifyPage = '<title>Bar</title>';
+			inject(window, options, function(result) {
+				assert.isDefined(result.error);
+				assert.strictEqual(result.error, 'Page not verified - HTML did not contain: "<title>Bar</title>"');
+				done();
+			});
+		});
+
+	});
+
 });
 /* eslint-enable one-var, max-len, max-statements */

test/unit/lib/pa11y.js

@@ -340,6 +340,7 @@ describe('lib/pa11y', function() {
 				],
 				standard: 'Section508',
 				wait: 0,
+				verifyPage: null,
 				rootElement: null
 			});
 			assert.isFunction(phantom.mockPage.evaluate.firstCall.args[2]);

test/unit/mock/window.js

@@ -5,6 +5,9 @@ var sinon = require('sinon');
 module.exports = {
 	callPhantom: sinon.spy(),
 	document: {
+		documentElement: {
+			outerHTML: '<title>Foo</title>'
+		},
 		querySelector: sinon.stub().returns(null),
 		querySelectorAll: sinon.stub().returns([])
 	},