enh: Add link on emails to notifications settings

lib/DigestSender.php

@@ -188,6 +188,11 @@ public function sendDigestForUser(IUser $user, int $now, string $timezone, strin
 			);
 		}
 
+		$template->addBodyText(
+			$l10n->t('You can disable daily digest emails in the <a href="%s">settings</a>.', $this->urlGenerator->linkToRouteAbsolute('settings.PersonalSettings.index', ['section' => 'notifications'])),
+			$l10n->t('You can disable daily digest emails in the settings: %s', $this->urlGenerator->linkToRouteAbsolute('settings.PersonalSettings.index', ['section' => 'notifications']))
+		);
+
 		$template->addFooter('', $language);
 
 		$message = $this->mailer->createMessage();

lib/MailQueueHandler.php

@@ -341,6 +341,11 @@ function ($event) use ($timezone, $l) {
 			$template->addBodyListItem($l->n('and %n more ', 'and %n more ', $skippedCount));
 		}
 
+		$template->addBodyText(
+			$l->t('You can change the frequency of these emails or disable them in the <a href="%s">settings</a>.', $this->urlGenerator->linkToRouteAbsolute('settings.PersonalSettings.index', ['section' => 'notifications'])),
+			$l->t('You can change the frequency of these emails or disable them in the settings: %s', $this->urlGenerator->linkToRouteAbsolute('settings.PersonalSettings.index', ['section' => 'notifications']))
+		);
+
 		$template->addFooter('', $lang);
 
 		$message = $this->mailer->createMessage();

tests/MailQueueHandlerTest.php

@@ -284,7 +284,7 @@ public function testSendEmailToUser(): void {
 			->method('addHeader');
 		$template->expects($this->once())
 			->method('addHeading');
-		$template->expects($this->once())
+		$template->expects($this->exactly(2))
 			->method('addBodyText');
 		$template->expects($this->once())
 			->method('addFooter');