re-implement babel traverse cache pollution bug workaround

Differential Revision: D61917782
facebook · Sep 2, 2024 · e9b7d66 · e9b7d66
1 parent cef7a3c
commit e9b7d66
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Showing 3 changed files with 7 additions and 8 deletions.
diff --git a/packages/metro-source-map/package.json b/packages/metro-source-map/package.json
@@ -13,6 +13,7 @@
   },
   "dependencies": {
     "@babel/traverse": "^7.20.0",
+    "@babel/traverse--for-generate-function-map": "npm:@babel/traverse@^7.20.0",
     "@babel/types": "^7.20.0",
     "flow-enums-runtime": "^0.0.6",
     "invariant": "^2.2.4",

diff --git a/packages/metro-source-map/src/generateFunctionMap.js b/packages/metro-source-map/src/generateFunctionMap.js
@@ -17,7 +17,8 @@ import type {NodePath} from '@babel/traverse';
 import type {Node} from '@babel/types';
 import type {MetroBabelFileMetadata} from 'metro-babel-transformer';
 
-import traverse from '@babel/traverse';
+// $FlowFixMe[cannot-resolve-module] - resolves to @babel/traverse
+import traverseForGenerateFunctionMap from '@babel/traverse--for-generate-function-map';
 import {
   isAssignmentExpression,
   isClassBody,
@@ -222,19 +223,16 @@ function forEachMapping(
 
   // Traversing populates/pollutes the path cache (`traverse.cache.path`) with
   // values missing the `hub` property needed by Babel transformation, so we
-  // save, clear, and restore the cache around our traversal.
-  // See: https://github.com/facebook/metro/pull/854#issuecomment-1336499395
-  const previousCache = traverse.cache.path;
-  traverse.cache.clearPath();
-  traverse(ast, {
+  // use a separate copy of traverse to populate a separate cache to not pollute
+  // the main @babel/traverse cache. See: https://github.com/facebook/metro/pull/1340
+  traverseForGenerateFunctionMap(ast, {
     // Our visitor doesn't care about scope
     noScope: true,
 
     Function: visitor,
     Program: visitor,
     Class: visitor,
   });
-  traverse.cache.path = previousCache;
 }
 
 const ANONYMOUS_NAME = '<anonymous>';

diff --git a/yarn.lock b/yarn.lock
@@ -1089,7 +1089,7 @@
     "@babel/parser" "^7.22.5"
     "@babel/types" "^7.22.5"
 
-"@babel/traverse@^7.19.1", "@babel/traverse@^7.20.0", "@babel/traverse@^7.20.1", "@babel/traverse@^7.20.5", "@babel/traverse@^7.4.3":
+"@babel/traverse--for-generate-function-map@npm:@babel/traverse@^7.20.0", "@babel/traverse@^7.19.1", "@babel/traverse@^7.20.0", "@babel/traverse@^7.20.1", "@babel/traverse@^7.20.5", "@babel/traverse@^7.4.3":
   version "7.20.5"
   resolved "https://registry.yarnpkg.com/@babel/traverse/-/traverse-7.20.5.tgz#78eb244bea8270fdda1ef9af22a5d5e5b7e57133"
   integrity sha512-WM5ZNN3JITQIq9tFZaw1ojLU3WgWdtkxnhM1AegMS+PvHjkM5IXjmYEGY7yukz5XS4sJyEf2VzWjI8uAavhxBQ==