fix: drop Notion telemetry in the browser instead of fake responses

src/rewriters/custom/head.js

@@ -100,27 +100,66 @@ window.history.replaceState = new Proxy(window.history.replaceState, {
   },
 });
 (function () {
-  const replacedUrl = function (url) {
+  // Notion fires fire-and-forget telemetry and analytics to these hosts. Nooxy
+  // previously bounced them off the proxy via a same-origin pseudo endpoint,
+  // which produced a noisy 200 log line for every request. We now drop them
+  // entirely in the browser so no network request is made and nothing reaches
+  // the proxy. These responses were already discarded, so the page is unaffected.
+  const pathOf = function (url) {
+    const noScheme = url.replace(/^https?:\/\/[^\\/]*/, '');
+    return noScheme.split('?')[0].split('#')[0];
+  };
+
+  const isSuppressedUrl = function (url) {
+    // Same-origin Notion keepalive ping is non-essential and only adds proxy log noise.
+    if (pathOf(url) === '/api/v3/ping') {
+      return true;
+    }
     const match = /^https?:\/\/([^\\/]*)/.exec(url);
     const domain = match ? match[1] : '';
-    if (
+    // file.notion.so and file.notion.com serve signed PDF and attachment downloads.
+    // They are real content, not telemetry, so they must not be dropped. The blanket
+    // notion.so rule below would otherwise leave react-pdf with an empty body. Keep
+    // this comment slash-free: the converter mis-parses a bare slash as a regex.
+    if (domain === 'file.notion.so' || domain === 'file.notion.com') {
+      return false;
+    }
+    return (
       (domain.endsWith('notion.so') && !domain.endsWith('msgstore.www.notion.so')) ||
       domain.endsWith('splunkcloud.com') ||
       domain.endsWith('statsigapi.net')
-    ) {
-      // console.info('[NOOXY]', 'Suppress request:', url);
-      return url.replace(/^.*:(.*)\/\//, '/200/$1');
+    );
+  };
+
+  const urlOf = function (input) {
+    if (typeof input === 'string') {
+      return input;
+    }
+    // Request object
+    if (input && typeof input.url === 'string') {
+      return input.url;
+    }
+    try {
+      return String(input);
+    } catch (_e) {
+      return '';
     }
-    return url;
   };
 
   window.fetch = new Proxy(window.fetch, {
     apply: function (target, that, args) {
-      let url = args[0];
-      const rest = Array.prototype.slice.call(args, 1);
-      url = replacedUrl(url);
-      // console.info('[NOOXY]', 'Fetch Request:', url);
-      return Reflect.apply(target, that, [url].concat(rest));
+      if (isSuppressedUrl(urlOf(args[0]))) {
+        // Silently drop: resolve with a synthetic success, make no network call.
+        // console.info('[NOOXY]', 'Dropped request:', urlOf(args[0]));
+        return Promise.resolve(
+          new Response('{}', {
+            status: 200,
+            statusText: 'OK',
+            headers: { 'content-type': 'application/json' },
+          }),
+        );
+      }
+      return Reflect.apply(target, that, args);
     },
   });
 
@@ -130,10 +169,14 @@ window.history.replaceState = new Proxy(window.history.replaceState, {
       xhr.open = new Proxy(xhr.open, {
         apply: function (target, that, args) {
           const method = args[0];
-          let url = args[1];
+          const url = args[1];
           const rest = Array.prototype.slice.call(args, 2);
-          url = replacedUrl(url);
-          // console.info('[NOOXY]', 'XML Request:', url);
+          if (isSuppressedUrl(urlOf(url))) {
+            // Resolve locally via a data: URL (allowed by connect-src 'data:') so
+            // the request never leaves the browser and never hits the proxy.
+            // console.info('[NOOXY]', 'Dropped request:', urlOf(url));
+            return Reflect.apply(target, that, ['GET', 'data:application/json,%7B%7D'].concat(rest));
+          }
           return Reflect.apply(target, that, [method, url].concat(rest));
         },
       });