Initial import of GitHubA11yFixes.

This marks comment and commit group headers as headings for accessibility.

Author: jcsteh

GitHubA11yFixes.user.js

@@ -0,0 +1,51 @@
+// ==UserScript==
+// @name           GitHub Accessibility Fixes
+// @namespace      http://axSgrease.nvaccess.org/
+// @description    Improves the accessibility of GitHub.
+// @author         James Teh <jamie@nvaccess.org>
+// @copyright 2015 NV Access Limited
+// @license GNU General Public License version 2.0
+// @version        2015.2
+// @grant GM_log
+// @include https://github.com/*
+// ==/UserScript==
+
+function makeHeading(elem, level) {
+	elem.setAttribute("role", "heading");
+	elem.setAttribute("aria-level", level);
+}
+
+function tweak(target) {
+	var res = document.location.href.match(/github.com\/[^\/]+\/[^\/]+\/([^\/]+)(\/?)/);
+	if (["issues", "pull"].indexOf(res[1]) >= 0 && res[2] == "/") {
+		// Issue or pull request.
+		// Comment headers.
+		for (elem of target.querySelectorAll(".timeline-comment-header-text, .discussion-item-header"))
+			makeHeading(elem, 3);
+	} else if (res[1] == "commits" && res[2] == "/") {
+		// Commits.
+		// Commit group headers.
+		for (elem of target.querySelectorAll(".commit-group-title"))
+			makeHeading(elem, 2);
+	}
+}
+
+var observer = new MutationObserver(function(mutations) {
+	for (var mutation of mutations) {
+		try {
+			if (mutation.type === "childList") {
+				for (var node of mutation.addedNodes) {
+					if (node.nodeType != Node.ELEMENT_NODE)
+						continue;
+					tweak(node);
+				}
+			}
+		} catch (e) {
+			// Catch exceptions for individual mutations so other mutations are still handled.
+			GM_log("Exception while handling mutation: " + e);
+		}
+	}
+});
+observer.observe(document, {childList: true, subtree: true});
+
+tweak(document);