1 files changed, 56 insertions, 0 deletions
diff --git a/src/js/firstparties/facebook.js b/src/js/firstparties/facebook.js
new file mode 100644
index 0000000..2c5d299
--- /dev/null
+++ b/src/js/firstparties/facebook.js
@@ -0,0 +1,56 @@
+/* globals findInAllFrames:false, observeMutations:false */
+// Adapted from https://github.com/mgziminsky/FacebookTrackingRemoval
+// this should only run on facebook.com, messenger.com, and
+// facebookcorewwwi.onion
+let fb_wrapped_link = `a[href*='${document.domain.split(".").slice(-2).join(".")}/l.php?']:not([aria-label])`;
+
+// remove all attributes from a link except for class and ARIA attributes
+function cleanAttrs(elem) {
+  for (let i = elem.attributes.length - 1; i >= 0; --i) {
+    const attr = elem.attributes[i];
+    if (attr.name !== 'class' && !attr.name.startsWith('aria-')) {
+      elem.removeAttribute(attr.name);
+    }
+  }
+}
+
+// Remove excessive attributes and event listeners from link a and replace
+// its destination with href
+function cleanLink(a) {
+  let href = new URL(a.href).searchParams.get('u');
+
+  // If we can't extract a good URL, abort without breaking the links
+  if (!window.isURL(href)) {
+    return;
+  }
+
+  let href_url = new URL(href);
+  href_url.searchParams.delete('fbclid');
+  href = href_url.toString();
+
+  cleanAttrs(a);
+  a.href = href;
+  a.rel = "noreferrer";
+  a.target = "_blank";
+  a.addEventListener("click", function (e) { e.stopImmediatePropagation(); }, true);
+  a.addEventListener("mousedown", function (e) { e.stopImmediatePropagation(); }, true);
+  a.addEventListener("mouseup", function (e) { e.stopImmediatePropagation(); }, true);
+  a.addEventListener("mouseover", function (e) { e.stopImmediatePropagation(); }, true);
+}
+
+// TODO race condition; fix waiting on https://crbug.com/478183
+chrome.runtime.sendMessage({
+  type: "checkEnabled"
+}, function (enabled) {
+  if (!enabled) {
+    return;
+  }
+
+  // unwrap wrapped links in the original page
+  findInAllFrames(fb_wrapped_link).forEach((link) => {
+    cleanLink(link);
+  });
+
+  // Execute redirect unwrapping each time new content is added to the page
+  observeMutations(fb_wrapped_link, cleanLink);
+});