Move crates under a sub folder to clean up the code

crates/milli/tests/search/sort.rs

@@ -0,0 +1,23 @@
+use big_s::S;
+use milli::Criterion::{Attribute, Exactness, Proximity, Typo, Words};
+use milli::{AscDesc, Error, Member, Search, TermsMatchingStrategy, UserError};
+
+use crate::search::{self, EXTERNAL_DOCUMENTS_IDS};
+
+#[test]
+fn sort_ranking_rule_missing() {
+    let criteria = vec![Words, Typo, Proximity, Attribute, Exactness];
+    // sortables: `tag` and `asc_desc_rank`
+    let index = search::setup_search_index_with_criteria(&criteria);
+    let rtxn = index.read_txn().unwrap();
+
+    let mut search = Search::new(&rtxn, &index);
+    search.query(search::TEST_QUERY);
+    search.limit(EXTERNAL_DOCUMENTS_IDS.len());
+
+    search.terms_matching_strategy(TermsMatchingStrategy::default());
+    search.sort_criteria(vec![AscDesc::Asc(Member::Field(S("tag")))]);
+
+    let result = search.execute();
+    assert!(matches!(result, Err(Error::UserError(UserError::SortRankingRuleMissing))));
+}