From 0d2e9522ffbfc045177b9b21a57c29d907fac635 Mon Sep 17 00:00:00 2001
From: Echo <ChaosExAnima@users.noreply.github.com>
Date: Thu, 27 Nov 2025 14:10:55 +0100
Subject: [PATCH] Replace Rails UJS library (#37031)

---
 app/javascript/mastodon/common.ts      |  8 +--
 app/javascript/mastodon/utils/links.ts | 88 ++++++++++++++++++++++++++
 package.json                           |  2 -
 yarn.lock                              | 16 -----
 4 files changed, 90 insertions(+), 24 deletions(-)
 create mode 100644 app/javascript/mastodon/utils/links.ts

diff --git a/app/javascript/mastodon/common.ts b/app/javascript/mastodon/common.ts
index e621a24e39..33d2b5ad17 100644
--- a/app/javascript/mastodon/common.ts
+++ b/app/javascript/mastodon/common.ts
@@ -1,9 +1,5 @@
-import Rails from '@rails/ujs';
+import { setupLinkListeners } from './utils/links';
 
 export function start() {
-  try {
-    Rails.start();
-  } catch {
-    // If called twice
-  }
+  setupLinkListeners();
 }
diff --git a/app/javascript/mastodon/utils/links.ts b/app/javascript/mastodon/utils/links.ts
new file mode 100644
index 0000000000..02b74bde4d
--- /dev/null
+++ b/app/javascript/mastodon/utils/links.ts
@@ -0,0 +1,88 @@
+import { on } from 'delegated-events';
+
+export function setupLinkListeners() {
+  on('click', 'a[data-confirm]', handleConfirmLink);
+
+  // We don't want to target links with data-confirm here, as those are handled already.
+  on('click', 'a[data-method]:not([data-confirm])', handleMethodLink);
+}
+
+function handleConfirmLink(event: MouseEvent) {
+  const anchor = event.currentTarget;
+  if (!(anchor instanceof HTMLAnchorElement)) {
+    return;
+  }
+  const message = anchor.dataset.confirm;
+  if (!message || !window.confirm(message)) {
+    event.preventDefault();
+    return;
+  }
+
+  if (anchor.dataset.method) {
+    handleMethodLink(event);
+  }
+}
+
+function handleMethodLink(event: MouseEvent) {
+  const anchor = event.currentTarget;
+  if (!(anchor instanceof HTMLAnchorElement)) {
+    return;
+  }
+
+  const method = anchor.dataset.method?.toLowerCase();
+  if (!method) {
+    return;
+  }
+  event.preventDefault();
+
+  // Create and submit a form with the specified method.
+  const form = document.createElement('form');
+  form.method = 'post';
+  form.action = anchor.href;
+
+  // Add the hidden _method input to simulate other HTTP methods.
+  const methodInput = document.createElement('input');
+  methodInput.type = 'hidden';
+  methodInput.name = '_method';
+  methodInput.value = method;
+  form.appendChild(methodInput);
+
+  // Add CSRF token if available for same-origin requests.
+  const csrf = getCSRFToken();
+  if (csrf && !isCrossDomain(anchor.href)) {
+    const csrfInput = document.createElement('input');
+    csrfInput.type = 'hidden';
+    csrfInput.name = csrf.param;
+    csrfInput.value = csrf.token;
+    form.appendChild(csrfInput);
+  }
+
+  // The form needs to be in the document to be submitted.
+  form.style.display = 'none';
+  document.body.appendChild(form);
+
+  // We use requestSubmit to ensure any form submit handlers are properly invoked.
+  form.requestSubmit();
+}
+
+function getCSRFToken() {
+  const param = document.querySelector<HTMLMetaElement>(
+    'meta[name="csrf-param"]',
+  );
+  const token = document.querySelector<HTMLMetaElement>(
+    'meta[name="csrf-token"]',
+  );
+  if (param && token) {
+    return { param: param.content, token: token.content };
+  }
+  return null;
+}
+
+function isCrossDomain(href: string) {
+  const link = document.createElement('a');
+  link.href = href;
+  return (
+    link.protocol !== window.location.protocol ||
+    link.host !== window.location.host
+  );
+}
diff --git a/package.json b/package.json
index e1c91fbda0..64a1a00193 100644
--- a/package.json
+++ b/package.json
@@ -48,7 +48,6 @@
     "@gamestdio/websocket": "^0.3.2",
     "@github/webauthn-json": "^2.1.1",
     "@optimize-lodash/rollup-plugin": "^5.0.2",
-    "@rails/ujs": "7.1.600",
     "@react-spring/web": "^9.7.5",
     "@reduxjs/toolkit": "^2.0.1",
     "@use-gesture/react": "^10.3.1",
@@ -149,7 +148,6 @@
     "@types/object-assign": "^4.0.30",
     "@types/prop-types": "^15.7.5",
     "@types/punycode": "^2.1.0",
-    "@types/rails__ujs": "^6.0.4",
     "@types/react": "^18.2.7",
     "@types/react-dom": "^18.2.4",
     "@types/react-helmet": "^6.1.6",
diff --git a/yarn.lock b/yarn.lock
index 38c04d9fd9..7b91fd6ff1 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -2708,7 +2708,6 @@ __metadata:
     "@gamestdio/websocket": "npm:^0.3.2"
     "@github/webauthn-json": "npm:^2.1.1"
     "@optimize-lodash/rollup-plugin": "npm:^5.0.2"
-    "@rails/ujs": "npm:7.1.600"
     "@react-spring/web": "npm:^9.7.5"
     "@reduxjs/toolkit": "npm:^2.0.1"
     "@storybook/addon-a11y": "npm:^10.0.6"
@@ -2728,7 +2727,6 @@ __metadata:
     "@types/object-assign": "npm:^4.0.30"
     "@types/prop-types": "npm:^15.7.5"
     "@types/punycode": "npm:^2.1.0"
-    "@types/rails__ujs": "npm:^6.0.4"
     "@types/react": "npm:^18.2.7"
     "@types/react-dom": "npm:^18.2.4"
     "@types/react-helmet": "npm:^6.1.6"
@@ -3205,13 +3203,6 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@rails/ujs@npm:7.1.600":
-  version: 7.1.600
-  resolution: "@rails/ujs@npm:7.1.600"
-  checksum: 10c0/0ccaa68a08fbc7b084ab89a1fe49520a5cba6d99f4b0feaf0cb3d00334c59d8d798932d7e49b84aa388875d039ea1e17eb115ed96a80ad157e408a13eceef53e
-  languageName: node
-  linkType: hard
-
 "@react-spring/animated@npm:~9.7.5":
   version: 9.7.5
   resolution: "@react-spring/animated@npm:9.7.5"
@@ -4297,13 +4288,6 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@types/rails__ujs@npm:^6.0.4":
-  version: 6.0.4
-  resolution: "@types/rails__ujs@npm:6.0.4"
-  checksum: 10c0/7477cb03a0e1339b9cd5c8ac4a197a153e2ff48742b2f527c5a39dcdf80f01493011e368483290d3717662c63066fada3ab203a335804cbb3573cf575f37007e
-  languageName: node
-  linkType: hard
-
 "@types/range-parser@npm:*":
   version: 1.2.7
   resolution: "@types/range-parser@npm:1.2.7"