Merge pull request #280 from cipherstash/fix/cte-resolution-in-sub-statements

fix(eql-mapper): resolution of CTE tables

Author: auxesis

packages/eql-mapper/src/lib.rs

@@ -809,6 +809,31 @@ mod test {
         );
     }
 
+    #[test]
+    fn cte_tables_can_be_resolved_in_subqueries() {
+        let schema = resolver(schema! {
+            tables: {
+                source_table: {
+                    id,
+                }
+
+                dest_table: {
+                    id,
+                }
+            }
+        });
+
+        let statement = parse(
+            "
+            WITH fd AS ( SELECT id FROM source_table )
+            INSERT INTO dest_table ( id )
+            SELECT id FROM fd RETURNING id
+        ",
+        );
+
+        type_check(schema, &statement).unwrap();
+    }
+
     #[test]
     fn aggregates() {
         // init_tracing();

packages/eql-mapper/src/scope_tracker.rs

@@ -297,17 +297,20 @@ impl<'ast> Visitor<'ast> for ScopeTracker<'ast> {
 
     fn enter<N: Visitable>(&mut self, node: &'ast N) -> ControlFlow<Break<Self::Error>> {
         if node.downcast_ref::<Statement>().is_some() {
-            let root = Scope::new_root();
-            self.stack.push(root.clone());
-            return ControlFlow::Continue(());
+            match self.stack.last() {
+                Some(scope) => {
+                    self.stack.push(Scope::new_child(scope));
+                }
+                None => {
+                    self.stack.push(Scope::new_root());
+                }
+            }
         }
 
         if node.downcast_ref::<Query>().is_some() {
             match self.stack.last() {
                 Some(scope) => {
-                    let child = Scope::new_child(scope);
-                    self.stack.push(child.clone());
-                    return ControlFlow::Continue(());
+                    self.stack.push(Scope::new_child(scope));
                 }
                 None => return ControlFlow::Break(Break::Err(ScopeError::NoCurrentScope)),
             }