Disallow duplicated AST nodes (#11807)

packages/babel-helper-create-class-features-plugin/src/decorators.js

@@ -137,7 +137,7 @@ export function buildDecoratedClass(ref, path, elements, file) {
   let replacement = template.expression.ast`
     ${addDecorateHelper(file)}(
       ${classDecorators || t.nullLiteral()},
-      function (${initializeId}, ${superClass ? superId : null}) {
+      function (${initializeId}, ${superClass ? t.cloneNode(superId) : null}) {
         ${node}
         return { F: ${t.cloneNode(node.id)}, d: ${definitions} };
       },
@@ -158,7 +158,7 @@ export function buildDecoratedClass(ref, path, elements, file) {
   }
 
   return {
-    instanceNodes: [template.statement.ast`${initializeId}(this)`],
+    instanceNodes: [template.statement.ast`${t.cloneNode(initializeId)}(this)`],
     wrapClass(path) {
       path.replaceWith(replacement);
       return path.get(classPathDesc);

packages/babel-helper-create-class-features-plugin/src/fields.js

@@ -45,8 +45,9 @@ export function buildPrivateNamesNodes(privateNamesMap, loose, state) {
     // In spec mode, only instance fields need a "private name" initializer
     // because static fields are directly assigned to a variable in the
     // buildPrivateStaticFieldInitSpec function.
-    const { id, static: isStatic, method: isMethod, getId, setId } = value;
+    const { static: isStatic, method: isMethod, getId, setId } = value;
     const isAccessor = getId || setId;
+    const id = t.cloneNode(value.id);
     if (loose) {
       initNodes.push(
         template.statement.ast`
@@ -157,7 +158,7 @@ const privateInVisitor = privateNameVisitorFactory({
     if (loose) {
       const { id } = privateNamesMap.get(name);
       path.replaceWith(template.expression.ast`
-        Object.prototype.hasOwnProperty.call(${right}, ${id})
+        Object.prototype.hasOwnProperty.call(${right}, ${t.cloneNode(id)})
       `);
       return;
     }
@@ -169,7 +170,7 @@ const privateInVisitor = privateNameVisitorFactory({
       return;
     }
 
-    path.replaceWith(template.expression.ast`${id}.has(${right})`);
+    path.replaceWith(template.expression.ast`${t.cloneNode(id)}.has(${right})`);
   },
 });
 
@@ -327,8 +328,8 @@ const privateNameHandlerLoose = {
 
     return template.expression`BASE(REF, PROP)[PROP]`({
       BASE: file.addHelper("classPrivateFieldLooseBase"),
-      REF: object,
-      PROP: privateNamesMap.get(name).id,
+      REF: t.cloneNode(object),
+      PROP: t.cloneNode(privateNamesMap.get(name).id),
     });
   },
 
@@ -387,7 +388,7 @@ function buildPrivateFieldInitLoose(ref, prop, privateNamesMap) {
   const value = prop.node.value || prop.scope.buildUndefinedNode();
 
   return template.statement.ast`
-    Object.defineProperty(${ref}, ${id}, {
+    Object.defineProperty(${ref}, ${t.cloneNode(id)}, {
       // configurable is false by default
       // enumerable is false by default
       writable: true,
@@ -400,7 +401,7 @@ function buildPrivateInstanceFieldInitSpec(ref, prop, privateNamesMap) {
   const { id } = privateNamesMap.get(prop.node.key.id.name);
   const value = prop.node.value || prop.scope.buildUndefinedNode();
 
-  return template.statement.ast`${id}.set(${ref}, {
+  return template.statement.ast`${t.cloneNode(id)}.set(${ref}, {
     // configurable is always false for private elements
     // enumerable is always false for private elements
     writable: true,
@@ -422,7 +423,7 @@ function buildPrivateStaticFieldInitSpec(prop, privateNamesMap) {
     });
 
     return template.statement.ast`
-      var ${id.name} = {
+      var ${t.cloneNode(id)} = {
         // configurable is false by default
         // enumerable is false by default
         // writable is false by default
@@ -434,7 +435,7 @@ function buildPrivateStaticFieldInitSpec(prop, privateNamesMap) {
 
   const value = prop.node.value || prop.scope.buildUndefinedNode();
   return template.statement.ast`
-    var ${id} = {
+    var ${t.cloneNode(id)} = {
       // configurable is false by default
       // enumerable is false by default
       writable: true,
@@ -603,14 +604,14 @@ function buildPrivateMethodDeclaration(prop, privateNamesMap, loose = false) {
   if (isStatic && !loose) {
     return t.variableDeclaration("var", [
       t.variableDeclarator(
-        id,
+        t.cloneNode(id),
         t.functionExpression(id, params, body, generator, async),
       ),
     ]);
   }
 
   return t.variableDeclaration("var", [
-    t.variableDeclarator(methodId, methodValue),
+    t.variableDeclarator(t.cloneNode(methodId), methodValue),
   ]);
 }
 

packages/babel-helper-create-class-features-plugin/src/index.js

@@ -1,3 +1,4 @@
+import { types as t } from "@babel/core";
 import nameFunction from "@babel/helper-function-name";
 import splitExportDeclaration from "@babel/helper-split-export-declaration";
 import {
@@ -129,7 +130,7 @@ export function createClassFeaturePlugin({
           nameFunction(path);
           ref = path.scope.generateUidIdentifier("class");
         } else {
-          ref = path.node.id;
+          ref = t.cloneNode(path.node.id);
         }
 
         // NODE: These three functions don't support decorators yet,

packages/babel-helper-create-class-features-plugin/src/misc.js

@@ -72,8 +72,14 @@ export function injectInitialization(path, constructor, nodes, renamer) {
   if (isDerived) {
     const bareSupers = [];
     constructor.traverse(findBareSupers, bareSupers);
+    let isFirst = true;
     for (const bareSuper of bareSupers) {
-      bareSuper.insertAfter(nodes);
+      if (isFirst) {
+        bareSuper.insertAfter(nodes);
+        isFirst = false;
+      } else {
+        bareSuper.insertAfter(nodes.map(n => t.cloneNode(n)));
+      }
     }
   } else {
     constructor.get("body").unshiftContainer("body", nodes);