fix: parse support of delete() functions

crates/pgls_statement_splitter/src/lib.rs

@@ -553,6 +553,56 @@ values ('insert', new.id, now());",
             ]);
     }
 
+    #[test]
+    fn hstore_function_calls() {
+        let calls = [
+            "hstore(ROW(1, 2))",
+            "akeys('a=>1'::hstore)",
+            "skeys('a=>1'::hstore)",
+            "avals('a=>1'::hstore)",
+            "svals('a=>1'::hstore)",
+            "hstore_to_array('a=>1'::hstore)",
+            "hstore_to_matrix('a=>1'::hstore)",
+            "hstore_to_json('a=>1'::hstore)",
+            "hstore_to_jsonb('a=>1'::hstore)",
+            "hstore_to_json_loose('a=>1'::hstore)",
+            "hstore_to_jsonb_loose('a=>1'::hstore)",
+            "slice('a=>1'::hstore, ARRAY['a'])",
+            "each('a=>1'::hstore)",
+            "exist('a=>1'::hstore, 'a')",
+            "defined('a=>1'::hstore, 'a')",
+            "delete(resource_attributes, 'gen_ai.system')",
+            "delete('a=>1,b=>2'::hstore, ARRAY['a', 'b'])",
+            "delete('a=>1,b=>2'::hstore, 'a=>1'::hstore)",
+            "DeLeTe(resource_attributes, 'gen_ai.system')",
+            "public.delete(resource_attributes, 'gen_ai.system')",
+            "delete /* hstore */ (resource_attributes, 'gen_ai.system')",
+            "populate_record(ROW(1, 2), 'f1=>42'::hstore)",
+        ];
+
+        for call in calls {
+            let statement = format!("SELECT {call};");
+            let tester = Tester::from(statement.as_str());
+            tester
+                .expect_statements(vec![statement.as_str()])
+                .assert_no_errors();
+
+            let range = tester.result.ranges[0];
+            if let Err(error) = pgls_query::parse(&statement[range]) {
+                panic!("Expected hstore function call to parse: {error}");
+            }
+        }
+
+        Tester::from(
+            "UPDATE data SET attributes = delete(attributes, 'obsolete'); DELETE FROM data;",
+        )
+        .expect_statements(vec![
+            "UPDATE data SET attributes = delete(attributes, 'obsolete');",
+            "DELETE FROM data;",
+        ])
+        .assert_no_errors();
+    }
+
     #[test]
     fn with_ordinality() {
         Tester::from("insert into table (col) select 1 from other t cross join lateral jsonb_array_elements(t.buttons) with ordinality as a(b, nr) where t.buttons is not null;").expect_statements(vec!["insert into table (col) select 1 from other t cross join lateral jsonb_array_elements(t.buttons) with ordinality as a(b, nr) where t.buttons is not null;"]);

crates/pgls_statement_splitter/src/splitter/common.rs

@@ -261,6 +261,11 @@ pub(crate) fn unknown(p: &mut Splitter, exclude: &[SyntaxKind]) -> SplitterResul
 
                     p.advance()?;
                 }
+                // DELETE is also an unreserved keyword used by hstore's delete() function.
+                // A DELETE statement must be followed by FROM, so `delete(` cannot start one.
+                Some(SyntaxKind::DELETE_KW) if p.look_ahead(true) == SyntaxKind::L_PAREN => {
+                    p.advance()?;
+                }
                 Some(SyntaxKind::INSERT_KW)
                 | Some(SyntaxKind::UPDATE_KW)
                 | Some(SyntaxKind::DELETE_KW) => {

crates/pgls_workspace/src/workspace/server/document.rs

@@ -524,6 +524,19 @@ $$;";
         assert_eq!(results[1].1.end(), 39.into());
     }
 
+    #[test]
+    fn hstore_delete_function_has_no_syntax_diagnostic() {
+        let input = "SELECT delete(resource_attributes, 'gen_ai.system');";
+        let d = Document::new(input.to_string(), 1);
+
+        assert!(d.document_diagnostics().is_empty());
+
+        let results = d.iter(AnalyserDiagnosticsMapper).collect::<Vec<_>>();
+        assert_eq!(results.len(), 1);
+        assert!(results[0].0.is_some());
+        assert!(results[0].1.is_none());
+    }
+
     #[test]
     fn test_execute_statement_mapper() {
         let input = "SELECT 1; INVALID SYNTAX HERE;";