refactor(traverse)!: replace find_scope with ancestor_scopes retu…

…rning iterator (#4693)

Same as #4692. Replace `find_scope` and `find_scope_by_flags` with `ancestor_scopes ` method which returns an iterator. This does the same thing, but is more idiomatic.

crates/oxc_transformer/src/react/jsx_self.rs

@@ -1,7 +1,7 @@
 use oxc_ast::ast::*;
 use oxc_diagnostics::OxcDiagnostic;
 use oxc_span::{Span, SPAN};
-use oxc_traverse::{Ancestor, FinderRet, TraverseCtx};
+use oxc_traverse::{Ancestor, TraverseCtx};
 
 use crate::context::Ctx;
 
@@ -44,13 +44,14 @@ impl<'a> ReactJsxSelf<'a> {
 
     #[allow(clippy::unused_self)]
     fn is_inside_constructor(&self, ctx: &TraverseCtx<'a>) -> bool {
-        ctx.find_scope_by_flags(|flags| {
+        for scope_id in ctx.ancestor_scopes() {
+            let flags = ctx.scopes().get_flags(scope_id);
             if flags.is_block() || flags.is_arrow() {
-                return FinderRet::Continue;
+                continue;
             }
-            FinderRet::Found(flags.is_constructor())
-        })
-        .unwrap_or(false)
+            return flags.is_constructor();
+        }
+        unreachable!(); // Always hit `Program` and exit before loop ends
     }
 
     fn has_no_super_class(ctx: &TraverseCtx<'a>) -> bool {

crates/oxc_traverse/src/context/mod.rs

@@ -25,7 +25,7 @@ pub use scoping::TraverseScoping;
 /// Provides ability to:
 /// * Query parent/ancestor of current node via [`parent`], [`ancestor`], [`ancestors`].
 /// * Get scopes tree and symbols table via [`scopes`], [`symbols`], [`scopes_mut`], [`symbols_mut`],
-///   [`find_scope`], [`find_scope_by_flags`].
+///   [`ancestor_scopes`].
 /// * Create AST nodes via AST builder [`ast`].
 /// * Allocate into arena via [`alloc`].
 ///
@@ -100,8 +100,7 @@ pub use scoping::TraverseScoping;
 /// [`symbols`]: `TraverseCtx::symbols`
 /// [`scopes_mut`]: `TraverseCtx::scopes_mut`
 /// [`symbols_mut`]: `TraverseCtx::symbols_mut`
-/// [`find_scope`]: `TraverseCtx::find_scope`
-/// [`find_scope_by_flags`]: `TraverseCtx::find_scope_by_flags`
+/// [`ancestor_scopes`]: `TraverseCtx::ancestor_scopes`
 /// [`ast`]: `TraverseCtx::ast`
 /// [`alloc`]: `TraverseCtx::alloc`
 pub struct TraverseCtx<'a> {
@@ -110,13 +109,6 @@ pub struct TraverseCtx<'a> {
     pub ast: AstBuilder<'a>,
 }
 
-/// Return value of closure when using [`TraverseCtx::find_scope`].
-pub enum FinderRet<T> {
-    Found(T),
-    Stop,
-    Continue,
-}
-
 // Public methods
 impl<'a> TraverseCtx<'a> {
     /// Create new traversal context.
@@ -223,38 +215,11 @@ impl<'a> TraverseCtx<'a> {
         self.scoping.symbols_mut()
     }
 
-    /// Walk up trail of scopes to find a scope.
-    ///
-    /// `finder` is called with `ScopeId`.
-    ///
-    /// `finder` should return:
-    /// * `FinderRet::Found(value)` to stop walking and return `Some(value)`.
-    /// * `FinderRet::Stop` to stop walking and return `None`.
-    /// * `FinderRet::Continue` to continue walking up.
-    ///
-    /// This is a shortcut for `ctx.scoping.find_scope`.
-    pub fn find_scope<F, O>(&self, finder: F) -> Option<O>
-    where
-        F: Fn(ScopeId) -> FinderRet<O>,
-    {
-        self.scoping.find_scope(finder)
-    }
-
-    /// Walk up trail of scopes to find a scope by checking `ScopeFlags`.
-    ///
-    /// `finder` is called with `ScopeFlags`.
-    ///
-    /// `finder` should return:
-    /// * `FinderRet::Found(value)` to stop walking and return `Some(value)`.
-    /// * `FinderRet::Stop` to stop walking and return `None`.
-    /// * `FinderRet::Continue` to continue walking up.
+    /// Get iterator over scopes, starting with current scope and working up.
     ///
-    /// This is a shortcut for `ctx.scoping.find_scope_by_flags`.
-    pub fn find_scope_by_flags<F, O>(&self, finder: F) -> Option<O>
-    where
-        F: Fn(ScopeFlags) -> FinderRet<O>,
-    {
-        self.scoping.find_scope_by_flags(finder)
+    /// This is a shortcut for `ctx.scoping.parent_scopes`.
+    pub fn ancestor_scopes(&self) -> impl Iterator<Item = ScopeId> + '_ {
+        self.scoping.ancestor_scopes()
     }
 
     /// Create new scope as child of provided scope.

crates/oxc_traverse/src/context/scoping.rs

@@ -14,8 +14,6 @@ use oxc_syntax::{
     symbol::{SymbolFlags, SymbolId},
 };
 
-use super::FinderRet;
-
 /// Traverse scope context.
 ///
 /// Contains the scope tree and symbols table, and provides methods to access them.
@@ -70,50 +68,9 @@ impl TraverseScoping {
         &mut self.symbols
     }
 
-    /// Walk up trail of scopes to find a scope.
-    ///
-    /// `finder` is called with `ScopeId`.
-    ///
-    /// `finder` should return:
-    /// * `FinderRet::Found(value)` to stop walking and return `Some(value)`.
-    /// * `FinderRet::Stop` to stop walking and return `None`.
-    /// * `FinderRet::Continue` to continue walking up.
-    pub fn find_scope<F, O>(&self, finder: F) -> Option<O>
-    where
-        F: Fn(ScopeId) -> FinderRet<O>,
-    {
-        let mut scope_id = self.current_scope_id;
-        loop {
-            match finder(scope_id) {
-                FinderRet::Found(res) => return Some(res),
-                FinderRet::Stop => return None,
-                FinderRet::Continue => {}
-            }
-
-            if let Some(parent_scope_id) = self.scopes.get_parent_id(scope_id) {
-                scope_id = parent_scope_id;
-            } else {
-                return None;
-            }
-        }
-    }
-
-    /// Walk up trail of scopes to find a scope by checking `ScopeFlags`.
-    ///
-    /// `finder` is called with `ScopeFlags`.
-    ///
-    /// `finder` should return:
-    /// * `FinderRet::Found(value)` to stop walking and return `Some(value)`.
-    /// * `FinderRet::Stop` to stop walking and return `None`.
-    /// * `FinderRet::Continue` to continue walking up.
-    pub fn find_scope_by_flags<F, O>(&self, finder: F) -> Option<O>
-    where
-        F: Fn(ScopeFlags) -> FinderRet<O>,
-    {
-        self.find_scope(|scope_id| {
-            let flags = self.scopes.get_flags(scope_id);
-            finder(flags)
-        })
+    /// Get iterator over scopes, starting with current scope and working up
+    pub fn ancestor_scopes(&self) -> impl Iterator<Item = ScopeId> + '_ {
+        self.scopes.ancestors(self.current_scope_id)
     }
 
     /// Create new scope as child of provided scope.

crates/oxc_traverse/src/lib.rs

@@ -67,7 +67,7 @@ use oxc_semantic::{ScopeTree, SymbolTable};
 pub mod ancestor;
 pub use ancestor::Ancestor;
 mod context;
-pub use context::{FinderRet, TraverseAncestry, TraverseCtx, TraverseScoping};
+pub use context::{TraverseAncestry, TraverseCtx, TraverseScoping};
 #[allow(clippy::module_inception)]
 mod traverse;
 pub use traverse::Traverse;