Open all Signal links in app

ts/util/sgnlHref.ts

@@ -1,10 +1,11 @@
-// Copyright 2020-2021 Signal Messenger, LLC
+// Copyright 2020-2022 Signal Messenger, LLC
 // SPDX-License-Identifier: AGPL-3.0-only
 
 import type { LoggerType } from '../types/Logging';
 import { maybeParseUrl } from './url';
 import { isValidE164 } from './isValidE164';
 
+const SIGNAL_HOSTS = new Set(['signal.group', 'signal.art', 'signal.me']);
 const SIGNAL_DOT_ME_HASH_PREFIX = 'p/';
 
 function parseUrl(value: string | URL, logger: LoggerType): undefined | URL {
@@ -44,9 +45,7 @@ export function isSignalHttpsLink(
       !url.password &&
       !url.port &&
       url.protocol === 'https:' &&
-      (url.host === 'signal.group' ||
-        url.host === 'signal.art' ||
-        url.host === 'signal.me')
+      SIGNAL_HOSTS.has(url.host)
   );
 }
 
@@ -143,3 +142,25 @@ export function parseE164FromSignalDotMeHash(hash: string): undefined | string {
   const maybeE164 = hash.slice(SIGNAL_DOT_ME_HASH_PREFIX.length);
   return isValidE164(maybeE164, true) ? maybeE164 : undefined;
 }
+
+/**
+ * Converts `http://signal.group/#abc` to `https://signal.group/#abc`. Does the same for
+ * other Signal hosts, like signal.me. Does nothing to other URLs. Expects a valid href.
+ */
+export function rewriteSignalHrefsIfNecessary(href: string): string {
+  const resultUrl = new URL(href);
+
+  const isHttp = resultUrl.protocol === 'http:';
+  const isHttpOrHttps = isHttp || resultUrl.protocol === 'https:';
+
+  if (SIGNAL_HOSTS.has(resultUrl.host) && isHttpOrHttps) {
+    if (isHttp) {
+      resultUrl.protocol = 'https:';
+    }
+    resultUrl.username = '';
+    resultUrl.password = '';
+    return resultUrl.href;
+  }
+
+  return href;
+}