1 files changed, 19 insertions, 0 deletions
diff --git a/packages/frontend/src/scripts/extract-url-from-mfm.ts b/packages/frontend/src/scripts/extract-url-from-mfm.ts
new file mode 100644
index 0000000000..34e3eb6c19
--- /dev/null
+++ b/packages/frontend/src/scripts/extract-url-from-mfm.ts
@@ -0,0 +1,19 @@
+import * as mfm from 'mfm-js';
+import { unique } from '@/scripts/array';
+
+// unique without hash
+// [ http://a/#1, http://a/#2, http://b/#3 ] => [ http://a/#1, http://b/#3 ]
+const removeHash = (x: string) => x.replace(/#[^#]*$/, '');
+
+export function extractUrlFromMfm(nodes: mfm.MfmNode[], respectSilentFlag = true): string[] {
+	const urlNodes = mfm.extract(nodes, (node) => {
+		return (node.type === 'url') || (node.type === 'link' && (!respectSilentFlag || !node.props.silent));
+	});
+	const urls: string[] = unique(urlNodes.map(x => x.props.url));
+
+	return urls.reduce((array, url) => {
+		const urlWithoutHash = removeHash(url);
+		if (!array.map(x => removeHash(x)).includes(urlWithoutHash)) array.push(url);
+		return array;
+	}, [] as string[]);
+}