fix: "Map maximum size exceeded" in deepClone (#17142)

liuxingbaoyu · web-flow · commit 985f051c7c68 · 2025-03-02T13:31:55.000-05:00
diff --git a/packages/babel-core/src/transformation/util/clone-deep.ts b/packages/babel-core/src/transformation/util/clone-deep.ts
@@ -1,33 +1,73 @@
-//https://github.com/babel/babel/pull/14583#discussion_r882828856
-function deepClone(value: any, cache: Map<any, any>): any {
+const circleSet = new Set();
+let depth = 0;
+// https://github.com/babel/babel/pull/14583#discussion_r882828856
+function deepClone(
+  value: any,
+  cache: Map<any, any>,
+  allowCircle: boolean,
+): any {
   if (value !== null) {
-    if (cache.has(value)) return cache.get(value);
+    if (allowCircle) {
+      if (cache.has(value)) return cache.get(value);
+    } else if (++depth > 250) {
+      if (circleSet.has(value)) {
+        depth = 0;
+        circleSet.clear();
+        throw new Error("Babel-deepClone: Cycles are not allowed in AST");
+      }
+      circleSet.add(value);
+    }
     let cloned: any;
     if (Array.isArray(value)) {
       cloned = new Array(value.length);
-      cache.set(value, cloned);
+      if (allowCircle) cache.set(value, cloned);
       for (let i = 0; i < value.length; i++) {
         cloned[i] =
-          typeof value[i] !== "object" ? value[i] : deepClone(value[i], cache);
+          typeof value[i] !== "object"
+            ? value[i]
+            : deepClone(value[i], cache, allowCircle);
       }
     } else {
       cloned = {};
-      cache.set(value, cloned);
+      if (allowCircle) cache.set(value, cloned);
       const keys = Object.keys(value);
       for (let i = 0; i < keys.length; i++) {
         const key = keys[i];
         cloned[key] =
           typeof value[key] !== "object"
             ? value[key]
-            : deepClone(value[key], cache);
+            : deepClone(
+                value[key],
+                cache,
+                allowCircle ||
+                  key === "leadingComments" ||
+                  key === "innerComments" ||
+                  key === "trailingComments" ||
+                  key === "extra",
+              );
       }
     }
+    if (!allowCircle) {
+      if (depth-- > 250) circleSet.delete(value);
+    }
     return cloned;
   }
   return value;
 }
 
 export default function <T>(value: T): T {
   if (typeof value !== "object") return value;
-  return deepClone(value, new Map());
+
+  if (process.env.BABEL_8_BREAKING) {
+    if (!process.env.IS_PUBLISH && depth > 0) {
+      throw new Error("depth > 0");
+    }
+    return deepClone(value, new Map(), false);
+  } else {
+    try {
+      return deepClone(value, new Map(), true);
+    } catch (_) {
+      return structuredClone(value);
+    }
+  }
 }
diff --git a/packages/babel-core/test/transformation.js b/packages/babel-core/test/transformation.js
@@ -1,6 +1,8 @@
 import runner from "@babel/helper-transform-fixture-test-runner";
 import { fileURLToPath } from "url";
 import path from "path";
+import cloneDeep from "../lib/transformation/util/clone-deep.js";
+import { itBabel8 } from "$repo-utils";
 
 (runner.default || runner)(
   path.join(
@@ -9,3 +11,43 @@ import path from "path";
   ),
   "transformation",
 );
+
+describe("util", () => {
+  const clone = cloneDeep.default || cloneDeep;
+  itBabel8("deep clone", () => {
+    const circle = {};
+    circle.circle = circle;
+    const object = {};
+
+    const ast = {
+      type: "Program",
+      extra: {
+        circle,
+        circle2: circle,
+      },
+      object,
+      object2: object,
+    };
+    const cloned = clone(ast);
+
+    expect(cloned.object === ast.object).toBe(false);
+    expect(cloned.object === cloned.object2).toBe(false);
+
+    expect(cloned.extra.circle === ast.extra.circle).toBe(false);
+    expect(cloned.extra.circle === cloned.extra.circle2).toBe(true);
+    expect(cloned.extra.circle === cloned.extra.circle.circle).toBe(true);
+  });
+
+  itBabel8("deep clone circle", () => {
+    const circle = {};
+    circle.circle = circle;
+
+    const ast = {
+      type: "Program",
+      circle,
+    };
+    expect(() => {
+      clone(ast);
+    }).toThrow("Babel-deepClone: Cycles are not allowed in AST");
+  });
+});
