No Duplicating Tags (#2505)

* Error when trying to make tags with same name

* Formatting

core/src/api/tags.rs

@@ -88,6 +88,22 @@ pub(crate) fn mount() -> AlphaRouter<Ctx> {
 		.procedure("create", {
 			R.with2(library())
 				.mutation(|(_, library), args: TagCreateArgs| async move {
+					// Check if tag with the same name already exists
+					let existing_tag = library
+						.db
+						.tag()
+						.find_many(vec![tag::name::equals(Some(args.name.clone()))])
+						.select(tag::select!({ id }))
+						.exec()
+						.await?;
+
+					if !existing_tag.is_empty() {
+						return Err(rspc::Error::new(
+							ErrorCode::Conflict,
+							"Tag with the same name already exists".to_string(),
+						));
+					}
+
 					let created_tag = args.exec(&library).await?;
 
 					invalidate_query!(library, "tags.list");