1 files changed, 84 insertions, 0 deletions
diff --git a/browser/extensions/webcompat/shims/live-test-shim.js b/browser/extensions/webcompat/shims/live-test-shim.js
new file mode 100644
index 0000000000..552020820f
--- /dev/null
+++ b/browser/extensions/webcompat/shims/live-test-shim.js
@@ -0,0 +1,84 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/* globals browser */
+
+if (!window.LiveTestShimPromise) {
+  const originalUrl = document.currentScript.src;
+
+  const shimId = "LiveTestShim";
+
+  const sendMessageToAddon = (function() {
+    const pendingMessages = new Map();
+    const channel = new MessageChannel();
+    channel.port1.onerror = console.error;
+    channel.port1.onmessage = event => {
+      const { messageId, response } = event.data;
+      const resolve = pendingMessages.get(messageId);
+      if (resolve) {
+        pendingMessages.delete(messageId);
+        resolve(response);
+      }
+    };
+    function reconnect() {
+      const detail = {
+        pendingMessages: [...pendingMessages.values()],
+        port: channel.port2,
+        shimId,
+      };
+      window.dispatchEvent(new CustomEvent("ShimConnects", { detail }));
+    }
+    window.addEventListener("ShimHelperReady", reconnect);
+    reconnect();
+    return function(message) {
+      const messageId =
+        Math.random()
+          .toString(36)
+          .substring(2) + Date.now().toString(36);
+      return new Promise(resolve => {
+        const payload = {
+          message,
+          messageId,
+          shimId,
+        };
+        pendingMessages.set(messageId, resolve);
+        channel.port1.postMessage(payload);
+      });
+    };
+  })();
+
+  async function go(options) {
+    try {
+      const o = document.getElementById("shims");
+      const cl = o.classList;
+      cl.remove("red");
+      cl.add("green");
+      o.innerText = JSON.stringify(options || "");
+    } catch (_) {}
+
+    if (window !== top) {
+      return;
+    }
+
+    await sendMessageToAddon("optIn");
+
+    const s = document.createElement("script");
+    s.src = originalUrl;
+    document.head.appendChild(s);
+  }
+
+  window[`${shimId}Promise`] = sendMessageToAddon("getOptions").then(
+    options => {
+      if (document.readyState !== "loading") {
+        go(options);
+      } else {
+        window.addEventListener("DOMContentLoaded", () => {
+          go(options);
+        });
+      }
+    }
+  );
+}