feat(semantic): transform checker check child scope IDs (#5410)

Transform checker check child scope IDs. If we have to track child scope IDs, we should make sure they're correct!

crates/oxc/src/compiler.rs

@@ -74,6 +74,10 @@ pub trait CompilerInterface {
         true
     }
 
+    fn semantic_child_scope_ids(&self) -> bool {
+        false
+    }
+
     fn after_parse(&mut self, _parser_return: &mut ParserReturn) -> ControlFlow<()> {
         ControlFlow::Continue(())
     }
@@ -186,6 +190,7 @@ pub trait CompilerInterface {
     ) -> SemanticBuilderReturn<'a> {
         SemanticBuilder::new(source_text, source_type)
             .with_check_syntax_error(self.check_semantic_error())
+            .with_scope_tree_child_ids(self.semantic_child_scope_ids())
             .build_module_record(source_path, program)
             .build(program)
     }

crates/oxc_semantic/src/post_transform_checker.rs

@@ -130,6 +130,7 @@ pub fn check_semantic_after_transform(
     let allocator = Allocator::default();
     let program = program.clone_in(&allocator);
     let (symbols_rebuilt, scopes_rebuilt) = SemanticBuilder::new("", program.source_type)
+        .with_scope_tree_child_ids(scopes_after_transform.has_child_ids())
         .build(&program)
         .semantic
         .into_symbol_table_and_scope_tree();
@@ -366,6 +367,16 @@ impl<'s> PostTransformChecker<'s> {
                 self.errors.push_mismatch("Scope parent mismatch", scope_ids, parent_ids);
             }
 
+            // Check children match
+            if self.scoping_after_transform.scopes.has_child_ids() {
+                let child_ids = self.get_pair(scope_ids, |scoping, scope_id| {
+                    scoping.scopes.get_child_ids(scope_id).to_vec()
+                });
+                if self.remap_scope_ids_sets(&child_ids).is_mismatch() {
+                    self.errors.push_mismatch("Scope children mismatch", scope_ids, child_ids);
+                }
+            }
+
             // NB: Skip checking node IDs match - transformer does not set `AstNodeId`s
         }
     }
@@ -504,6 +515,28 @@ impl<'s> PostTransformChecker<'s> {
         Pair::new(self.scope_ids_map.get(scope_ids.after_transform), Some(scope_ids.rebuilt))
     }
 
+    /// Remap pair of arrays of `ScopeId`s.
+    /// Map `after_transform` IDs to `rebuilt` IDs.
+    /// Sort both sets.
+    fn remap_scope_ids_sets<V: AsRef<Vec<ScopeId>>>(
+        &self,
+        scope_ids: &Pair<V>,
+    ) -> Pair<Vec<Option<ScopeId>>> {
+        let mut after_transform = scope_ids
+            .after_transform
+            .as_ref()
+            .iter()
+            .map(|&scope_id| self.scope_ids_map.get(scope_id))
+            .collect::<Vec<_>>();
+        let mut rebuilt =
+            scope_ids.rebuilt.as_ref().iter().copied().map(Option::Some).collect::<Vec<_>>();
+
+        after_transform.sort_unstable();
+        rebuilt.sort_unstable();
+
+        Pair::new(after_transform, rebuilt)
+    }
+
     /// Remap pair of arrays of `SymbolId`s.
     /// Map `after_transform` IDs to `rebuilt` IDs.
     /// Sort both sets.