feat: Flag unsupported roles (#1064)

Adds `unsupported` property to the `lookupTable.role` dictionary. New option for `aria.isValidRole` to `flagUnsupported` roles. Defaults to `false` since this commons function is reused for multiple checks.

Part one of #918.

TODO: 
- Add `unsupported` to lookupTable.attributes
- Figure out what to do with globalAttributes, which are currently a flat array
- Add `axe.commons.support` API and enable control of it through `axe.configure`

## Reviewer checks

**Required fields, to be filled out by PR reviewer(s)**
- [x] Follows the commit message policy, appropriate for next version
- [x] Has documentation updated, a DU ticket, or requires no documentation change
- [x] Includes new tests, or was unnecessary
- [x] Code is reviewed for security by: @WilcoFiers

build/tasks/aria-supported.js

@@ -46,18 +46,30 @@ module.exports = function(grunt) {
 					.reduce((out, [key] = item) => {
 						switch (listType) {
 							case 'supported':
-								if (subject.includes(key)) {
+								if (
+									subject.hasOwnProperty(key) &&
+									subject[key].unsupported === false
+								) {
 									out.push([`${key}`, 'Yes']);
 								}
 								break;
 							case 'unsupported':
-								if (!subject.includes(key)) {
+								if (
+									(subject[key] && subject[key].unsupported === true) ||
+									!subject.hasOwnProperty(key)
+								) {
 									out.push([`${key}`, 'No']);
 								}
 								break;
 							case 'all':
 							default:
-								out.push([`${key}`, subject.includes(key) ? 'Yes' : 'No']);
+								out.push([
+									`${key}`,
+									subject.hasOwnProperty(key) &&
+									subject[key].unsupported === false
+										? 'Yes'
+										: 'No'
+								]);
 								break;
 						}
 						return out;
@@ -75,14 +87,11 @@ module.exports = function(grunt) {
 					} in axe-core.`,
 					mdTable([
 						['aria-role', 'axe-core support'],
-						...getDiff(roles, Object.keys(axe.commons.aria.lookupTable.role))
+						...getDiff(roles, axe.commons.aria.lookupTable.role)
 					]),
 					mdTable([
 						['aria-attribute', 'axe-core support'],
-						...getDiff(
-							aQaria,
-							Object.keys(axe.commons.aria.lookupTable.attributes)
-						)
+						...getDiff(aQaria, axe.commons.aria.lookupTable.attributes)
 					])
 				);
 				grunt.file.write(destFile, content);

lib/checks/aria/unsupportedrole.js

@@ -0,0 +1,3 @@
+return !axe.commons.aria.isValidRole(node.getAttribute('role'), {
+	flagUnsupported: true
+});

lib/checks/aria/unsupportedrole.json

@@ -0,0 +1,11 @@
+{
+  "id": "unsupportedrole",
+  "evaluate": "unsupportedrole.js",
+  "metadata": {
+    "impact": "critical",
+    "messages": {
+      "pass": "ARIA role is supported",
+      "fail": "The role used is not widely supported in assistive technologies"
+    }
+  }
+}