Re-enable trailing commas in DCL (#1318)

Author: MohamedAbdeen21

src/parser/mod.rs

@@ -46,6 +46,9 @@ pub enum ParserError {
     RecursionLimitExceeded,
 }
 
+// avoid clippy type_complexity warnings
+type ParsedAction = (Keyword, Option<Vec<Ident>>);
+
 // Use `Parser::expected` instead, if possible
 macro_rules! parser_err {
     ($MSG:expr, $loc:expr) => {
@@ -3334,6 +3337,29 @@ impl<'a> Parser<'a> {
         ret
     }
 
+    pub fn parse_actions_list(&mut self) -> Result<Vec<ParsedAction>, ParserError> {
+        let mut values = vec![];
+        loop {
+            values.push(self.parse_grant_permission()?);
+            if !self.consume_token(&Token::Comma) {
+                break;
+            } else if self.options.trailing_commas {
+                match self.peek_token().token {
+                    Token::Word(kw) if kw.keyword == Keyword::ON => {
+                        break;
+                    }
+                    Token::RParen
+                    | Token::SemiColon
+                    | Token::EOF
+                    | Token::RBracket
+                    | Token::RBrace => break,
+                    _ => continue,
+                }
+            }
+        }
+        Ok(values)
+    }
+
     /// Parse a comma-separated list of 1+ items accepted by `F`
     pub fn parse_comma_separated<T, F>(&mut self, mut f: F) -> Result<Vec<T>, ParserError>
     where
@@ -3347,9 +3373,7 @@ impl<'a> Parser<'a> {
             } else if self.options.trailing_commas {
                 match self.peek_token().token {
                     Token::Word(kw)
-                        if keywords::RESERVED_FOR_COLUMN_ALIAS
-                            .iter()
-                            .any(|d| kw.keyword == *d) =>
+                        if keywords::RESERVED_FOR_COLUMN_ALIAS.contains(&kw.keyword) =>
                     {
                         break;
                     }
@@ -9680,11 +9704,8 @@ impl<'a> Parser<'a> {
                 with_privileges_keyword: self.parse_keyword(Keyword::PRIVILEGES),
             }
         } else {
-            let old_value = self.options.trailing_commas;
-            self.options.trailing_commas = false;
-
             let (actions, err): (Vec<_>, Vec<_>) = self
-                .parse_comma_separated(Parser::parse_grant_permission)?
+                .parse_actions_list()?
                 .into_iter()
                 .map(|(kw, columns)| match kw {
                     Keyword::DELETE => Ok(Action::Delete),
@@ -9706,8 +9727,6 @@ impl<'a> Parser<'a> {
                 })
                 .partition(Result::is_ok);
 
-            self.options.trailing_commas = old_value;
-
             if !err.is_empty() {
                 let errors: Vec<Keyword> = err.into_iter().filter_map(|x| x.err()).collect();
                 return Err(ParserError::ParserError(format!(
@@ -9753,7 +9772,7 @@ impl<'a> Parser<'a> {
         Ok((privileges, objects))
     }
 
-    pub fn parse_grant_permission(&mut self) -> Result<(Keyword, Option<Vec<Ident>>), ParserError> {
+    pub fn parse_grant_permission(&mut self) -> Result<ParsedAction, ParserError> {
         if let Some(kw) = self.parse_one_of_keywords(&[
             Keyword::CONNECT,
             Keyword::CREATE,

tests/sqlparser_common.rs

@@ -8942,6 +8942,11 @@ fn parse_trailing_comma() {
         "CREATE TABLE employees (name TEXT, age INT)",
     );
 
+    trailing_commas.one_statement_parses_to(
+        "GRANT USAGE, SELECT, INSERT, ON p TO u",
+        "GRANT USAGE, SELECT, INSERT ON p TO u",
+    );
+
     trailing_commas.verified_stmt("SELECT album_id, name FROM track");
 
     trailing_commas.verified_stmt("SELECT * FROM track ORDER BY milliseconds");
@@ -8961,6 +8966,13 @@ fn parse_trailing_comma() {
         ParserError::ParserError("Expected an expression, found: from".to_string())
     );
 
+    assert_eq!(
+        trailing_commas
+            .parse_sql_statements("REVOKE USAGE, SELECT, ON p TO u")
+            .unwrap_err(),
+        ParserError::ParserError("Expected a privilege keyword, found: ON".to_string())
+    );
+
     assert_eq!(
         trailing_commas
             .parse_sql_statements("CREATE TABLE employees (name text, age int,)")