[main.js] getHTML: add aria-label to correct childnode (#291)

* [main.js] getHTML: add aria-label to correct childnode
Resolves #289

* [main.js] GetHTML: make handling of speakText more robust
* improve selectors
* update tests
part of #289

* address review comments

* fix whitespace

lib/main.js

@@ -570,9 +570,11 @@ function GetHTML(result) {
 
   // add speech text if there isn't one
   if (data.speakText){
-    for (var i=0, m=html.childNodes.length; i < m; i++)
-      html.childNodes[i].setAttribute("aria-hidden",true);
-    if (!html.getAttribute("aria-label")) html.setAttribute("aria-label",result.speakText);
+    var labelTarget = html.querySelector('.mjx-math');
+    for (child of labelTarget.childNodes) child.setAttribute("aria-hidden",true);
+    if (!labelTarget.getAttribute("aria-label")){
+    labelTarget.setAttribute("aria-label",result.speakText);
+    }
   }
   // remove automatically generated IDs
   var ids = html.querySelectorAll('[id^="MJXc-Node-"]');

test/issue207.js

@@ -17,7 +17,7 @@ tape('Generate dummy speechText', function(t) {
 
   mjSpeechTest = function(data, expected, desc) {
     var document = jsdom(data.html).defaultView.document;
-    var element = document.querySelector('.MJXc-display');
+    var element = document.querySelector('.mjx-math');
     var actual = element.getAttribute('aria-label');
     t.equal(actual, expected, 'HTML output contains speechText from ' + desc);
     document = jsdom(data.mml).defaultView.document;

test/issue289.js

@@ -0,0 +1,17 @@
+var tape = require('tape');
+var mjAPI = require("../lib/main.js");
+
+tape('HTML output: add aria-label to correct childnode', function(t) {
+    t.plan(1);
+    mjAPI.start();
+    var mml = '<math alttext="0"><mn>1</mn></math>';
+
+    mjAPI.typeset({
+        math: mml,
+        format: "MathML",
+        htmlNode: true,
+        html: true
+    }, function(data) {
+        t.equal(data.htmlNode.parentNode.querySelectorAll('[aria-label]').length, 1, 'Aria-label is unique');
+    });
+});