enhance(frontend): 外部サイトへのリンクは移動の前に警告を表示するように (MisskeyIO#558)

packages/frontend/src/scripts/warning-external-website.ts

@@ -0,0 +1,33 @@
+import { url as local } from '@/config.js';
+import { instance } from '@/instance.js';
+import { i18n } from '@/i18n.js';
+import * as os from '@/os.js';
+
+const isRegExp = /^\/(.+)\/(.*)$/;
+
+export async function warningExternalWebsite(ev: MouseEvent, url: string) {
+	const self = url.startsWith(local);
+	const isWellKnownWebsite = self || instance.wellKnownWebsites.some(expression => {
+		const r = isRegExp.exec(expression);
+		if (r) {
+			return new RegExp(r[1], r[2]).test(url);
+		} else return expression.split(' ').every(keyword => url.includes(keyword));
+	});
+
+	if (!self && !isWellKnownWebsite) {
+		ev.preventDefault();
+		ev.stopPropagation();
+
+		const confirm = await os.confirm({
+			type: 'warning',
+			title: i18n.ts.warningRedirectingExternalWebsiteTitle,
+			text: i18n.tsx.warningRedirectingExternalWebsiteDescription({ url }),
+		});
+
+		if (confirm.canceled) return false;
+
+		window.open(url, '_blank', 'noopener');
+	}
+
+	return true;
+}