Issue 5315 - Add support for Microsoft Edge

lib/csp.js

Index: lib/csp.js
===================================================================
--- a/lib/csp.js
+++ b/lib/csp.js
@@ -17,10 +17,12 @@
 
 "use strict";
 
-// Before Chrome 58, the webRequest API did not intercept WebSocket
-// connections (see https://crbug.com/129353). Hence we inject CSP headers,
-// below, as a workaround.
-if (!("WEBSOCKET" in chrome.webRequest.ResourceType))
+// The webRequest API doesn't support WebSocket connection blocking in Microsoft
+// Edge and versions of Chrome before 58. Therefore for those we inject CSP
+// headers below as a workaround. See https://crbug.com/129353 and
+// https://developer.microsoft.com/en-us/microsoft-edge/platform/issues/10297376/
+if (!chrome.webRequest.ResourceType ||
+    !("WEBSOCKET" in chrome.webRequest.ResourceType))
 {
   const {defaultMatcher} = require("matcher");
   const {BlockingFilter, RegExpFilter} = require("filterClasses");