remove comments, add test, add _template

lib/checks/mobile/target-offset-evaluate.js

@@ -12,11 +12,6 @@ export default function targetOffsetEvaluate(node, options, vNode) {
     if (getRoleType(vNeighbor) !== 'widget' || !isFocusable(vNeighbor)) {
       continue;
     }
-    // the offset code works off radius but we want our messaging to reflect diameter
-
-    // getOffeset can return null now
-    // pass early if size is 10x (just like target-size)
-    // handle null as well
 
     const offset =
       roundToSingleDecimal(getOffset(vNode, vNeighbor, minOffset / 2)) * 2;

locales/_template.json

@@ -885,7 +885,8 @@
         "default": "Element with negative tabindex has insufficient size (${data.width}px by ${data.height}px, should be at least ${data.minSize}px by ${data.minSize}px). Is this a target?",
         "contentOverflow": "Element size could not be accurately determined due to overflow content",
         "partiallyObscured": "Element with negative tabindex has insufficient size because it is partially obscured (smallest space is ${data.width}px by ${data.height}px, should be at least ${data.minSize}px by ${data.minSize}px). Is this a target?",
-        "partiallyObscuredNonTabbable": "Target has insufficient size because it is partially obscured by a neighbor with negative tabindex (smallest space is ${data.width}px by ${data.height}px, should be at least ${data.minSize}px by ${data.minSize}px). Is the neighbor a target?"
+        "partiallyObscuredNonTabbable": "Target has insufficient size because it is partially obscured by a neighbor with negative tabindex (smallest space is ${data.width}px by ${data.height}px, should be at least ${data.minSize}px by ${data.minSize}px). Is the neighbor a target?",
+        "tooManyRects": "Could not calculate calculate largest obscured rectangle as there are too many overlapping widgets"
       }
     },
     "header-present": {

test/checks/mobile/target-offset.js

@@ -120,6 +120,36 @@ describe('target-offset tests', () => {
     assert.deepEqual(relatedIds, ['#left', '#right']);
   });
 
+  it('returns false if there are too many focusable widgets', () => {
+    let html = '';
+    for (let i = 0; i < 100; i++) {
+      html += `
+        <tr>
+          <td><a href="#">Hello</a></td>
+          <td>Hello</td>
+          <td>Hello</td>
+          <td>Hello</td>
+          <td>Hello</td>
+          <td>Hello</td>
+          <td>Hello</td>
+          <td><button>view</button></td>
+          <td><button>download</button></td>
+          <td><button>expand</button></td>
+        </tr>
+      `;
+    }
+    const checkArgs = checkSetup(`
+      <div id="target" role="tabpanel" tabindex="0">
+        <table id="tab-table">${html}</table>
+      </div>
+    `);
+    assert.isFalse(checkEvaluate.apply(checkContext, checkArgs));
+    assert.deepEqual(checkContext._data, {
+      closestOffset: 0,
+      minOffset: 24
+    });
+  });
+
   describe('when neighbors are focusable but not tabbable', () => {
     it('returns undefined if all neighbors are not tabbable', () => {
       const checkArgs = checkSetup(