Revert "perf: Improve scope information collection performance" (#17005)

Revert "perf: Improve scope information collection performance (#16923)" This reverts commit ded1571.
babel · Dec 5, 2024 · f33704a · f33704a
1 parent 651bc0b
commit f33704a
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Showing 5 changed files with 13 additions and 126 deletions.
diff --git a/packages/babel-traverse/src/path/context.ts b/packages/babel-traverse/src/path/context.ts
@@ -133,29 +133,6 @@ export function stop(this: NodePath) {
   this._traverseFlags |= SHOULD_SKIP | SHOULD_STOP;
 }
 
-export function _forceSetScope(current: NodePath) {
-  let path = current.parentPath;
-
-  if (
-    // Skip method scope if is computed method key or decorator expression
-    ((current.key === "key" || current.listKey === "decorators") &&
-      path.isMethod()) ||
-    // Skip switch scope if for discriminant (`x` in `switch (x) {}`).
-    (current.key === "discriminant" && path.isSwitchStatement())
-  ) {
-    path = path.parentPath;
-  }
-
-  let target;
-  while (path && !target) {
-    target = path.scope;
-    path = path.parentPath;
-  }
-
-  current.scope = current.getScope(target);
-  current.scope?.init();
-}
-
 export function setScope(this: NodePath) {
   if (this.opts?.noScope) return;
 

diff --git a/packages/babel-traverse/src/path/lib/virtual-types.ts b/packages/babel-traverse/src/path/lib/virtual-types.ts
@@ -2,10 +2,7 @@ import type * as t from "@babel/types";
 
 export interface VirtualTypeAliases {
   BindingIdentifier: t.Identifier;
-  BlockScoped:
-    | t.FunctionDeclaration
-    | t.ClassDeclaration
-    | t.VariableDeclaration;
+  BlockScoped: t.Node;
   ExistentialTypeParam: t.ExistsTypeAnnotation;
   Expression: t.Expression;
   Flow: t.Flow | t.ImportDeclaration | t.ExportDeclaration | t.ImportSpecifier;
@@ -45,11 +42,7 @@ export const Scope: VirtualTypeMapping = ["Scopable", "Pattern"] as const;
 
 export const Referenced: VirtualTypeMapping = null;
 
-export const BlockScoped: VirtualTypeMapping = [
-  "FunctionDeclaration",
-  "ClassDeclaration",
-  "VariableDeclaration",
-] as const;
+export const BlockScoped: VirtualTypeMapping = null;
 
 export const Var: VirtualTypeMapping = ["VariableDeclaration"];
 

diff --git a/packages/babel-traverse/src/scope/index.ts b/packages/babel-traverse/src/scope/index.ts
@@ -1,7 +1,6 @@
 import Renamer from "./lib/renamer.ts";
 import type NodePath from "../path/index.ts";
 import traverse from "../index.ts";
-import traverseForScope from "./traverseForScope.ts";
 import Binding from "./binding.ts";
 import type { BindingKind } from "./binding.ts";
 import globals from "globals";
@@ -931,14 +930,17 @@ class Scope {
     // traverse does not visit the root node, here we explicitly collect
     // root node binding info when the root is not a Program.
     if (path.type !== "Program" && isExplodedVisitor(collectorVisitor)) {
+      for (const visit of collectorVisitor.enter) {
+        visit.call(state, path, state);
+      }
       const typeVisitors = collectorVisitor[path.type];
       if (typeVisitors) {
         for (const visit of typeVisitors.enter) {
           visit.call(state, path, state);
         }
       }
     }
-    traverseForScope(path, collectorVisitor, state);
+    path.traverse(collectorVisitor, state);
     this.crawling = false;
 
     // register assignments

diff --git a/packages/babel-traverse/src/scope/traverseForScope.ts b/packages/babel-traverse/src/scope/traverseForScope.ts
diff --git a/packages/babel-traverse/src/visitors.ts b/packages/babel-traverse/src/visitors.ts
@@ -104,9 +104,13 @@ function explode$1<S>(visitor: Visitor<S>): ExplodedVisitor<S> {
     const types = virtualTypes[nodeType];
     if (types !== null) {
       for (const type of types) {
-        // @ts-expect-error Expression produces too complex union
-        visitor[type] ??= {};
-        mergePair(visitor[type], fns);
+        // merge the visitor if necessary or just put it back in
+        if (visitor[type]) {
+          mergePair(visitor[type], fns);
+        } else {
+          // @ts-expect-error Expression produces too complex union
+          visitor[type] = fns;
+        }
       }
     } else {
       mergePair(visitor, fns);