set parent pointers as part of the ESTree parse

Summary:
Do a final traversal of the AST at the end of the conversion to set the parent pointers.
In the ESLint world, these are set by ESLint just before the lint run. This isn't helpful for us because it means we can't use them within the hermes packages (like in hermes-eslint or hermes-transform).

Reviewed By: pieterv

Differential Revision: D38064433

fbshipit-source-id: 7e6d4c3556e3961797dd96d45aaa8fb01096b639

tools/hermes-parser/js/hermes-eslint/src/index.js

@@ -60,6 +60,16 @@ function parseForESLint(
   visitorKeys: VisitorKeysType,
 } {
   const ast = parse(code, options);
+
+  // set the parent pointers
+  HermesParser.SimpleTraverser.traverse(ast, {
+    enter(node, parent) {
+      // $FlowExpectedError[cannot-write]
+      node.parent = parent;
+    },
+    leave() {},
+  });
+
   const scopeManager = analyze(ast, options);
 
   return {

tools/hermes-parser/js/hermes-parser/src/index.js

@@ -83,3 +83,5 @@ export function parse(
 }
 
 export type {ParserOptions} from './ParserOptions';
+export * from './traverse/SimpleTraverser';
+export * from './traverse/getVisitorKeys';

tools/hermes-parser/js/hermes-transform/src/traverse/SimpleTraverser.js → tools/hermes-parser/js/hermes-parser/src/traverse/SimpleTraverser.js

@@ -12,7 +12,7 @@
 
 import type {ESNode} from 'hermes-estree';
 
-import {getVisitorKeys, isNode} from '../getVisitorKeys';
+import {getVisitorKeys, isNode} from './getVisitorKeys';
 
 export type TraverserCallback = (node: ESNode, parent: ?ESNode) => void;
 export type TraverserOptions = $ReadOnly<{

tools/hermes-parser/js/hermes-transform/__tests__/traverse/NodeEventGenerator-test.js

@@ -13,7 +13,7 @@
 import type {ESNode, Program} from 'hermes-estree';
 
 import {parseForESLint} from 'hermes-eslint';
-import {SimpleTraverser} from '../../src/traverse/SimpleTraverser';
+import {SimpleTraverser} from 'hermes-parser';
 import {SafeEmitter} from '../../src/traverse/SafeEmitter';
 import {NodeEventGenerator} from '../../src/traverse/NodeEventGenerator';
 

tools/hermes-parser/js/hermes-transform/__tests__/traverse/traverse-test.js

@@ -54,25 +54,6 @@ describe('traverse', () => {
     ]);
   });
 
-  it('sets the parent pointers', () => {
-    const code = 'const x = 1;';
-    const {ast, scopeManager} = parseForESLint(code);
-
-    expect(ast.body[0]).not.toHaveProperty('parent');
-    traverse(code, ast, scopeManager, () => ({
-      '*'(node) {
-        expect(node).toHaveProperty('parent');
-        if (node.type === 'Program') {
-          // eslint-disable-next-line jest/no-conditional-expect
-          expect(node.parent).toBeNull();
-        } else {
-          // eslint-disable-next-line jest/no-conditional-expect
-          expect(node.parent).toHaveProperty('type');
-        }
-      },
-    }));
-  });
-
   it('passes an immutable context object', () => {
     const code = 'const x = 1;';
     const {ast, scopeManager} = parseForESLint(code);

tools/hermes-parser/js/hermes-transform/package.json

@@ -13,7 +13,8 @@
     "esquery": "^1.4.0",
     "flow-enums-runtime": "^0.0.6",
     "hermes-eslint": "0.9.0",
-    "hermes-estree": "0.9.0"
+    "hermes-estree": "0.9.0",
+    "hermes-parser": "0.9.0"
   },
   "peerDependencies": {
     "prettier": "^2.4.1"

tools/hermes-parser/js/hermes-transform/src/detachedNode.js

@@ -10,8 +10,7 @@
 
 import type {BaseNode, ESNode} from 'hermes-estree';
 
-import {getVisitorKeys, isNode} from './getVisitorKeys';
-import {SimpleTraverser} from './traverse/SimpleTraverser';
+import {SimpleTraverser, getVisitorKeys, isNode} from 'hermes-parser';
 
 export opaque type DetachedNode<+T> = T;
 export type MaybeDetachedNode<+T> = T | DetachedNode<T>;

tools/hermes-parser/js/hermes-transform/src/index.js

@@ -15,7 +15,7 @@ export type {TransformVisitor} from './transform/transform';
 export type {TransformContext} from './transform/TransformContext';
 export type {DetachedNode} from './detachedNode';
 
-export {SimpleTraverser} from './traverse/SimpleTraverser';
+export {SimpleTraverser} from 'hermes-parser';
 export {traverse, traverseWithContext} from './traverse/traverse';
 export {transform} from './transform/transform';
 export * as t from './generated/node-types';

tools/hermes-parser/js/hermes-transform/src/transform/comments/prettier/main/comments.js

@@ -57,7 +57,8 @@ function getSortedChildNodes(node, options, resultArray) {
             key !== 'precedingNode' &&
             key !== 'followingNode' &&
             key !== 'tokens' &&
-            key !== 'comments',
+            key !== 'comments' &&
+            key !== 'parent',
         )
         .map(([, value]) => value));
 

tools/hermes-parser/js/hermes-transform/src/transform/mutations/RemoveComment.js

@@ -9,10 +9,8 @@
  */
 
 import type {Comment, Program} from 'hermes-estree';
-import {
-  SimpleTraverser,
-  SimpleTraverserBreak,
-} from '../../traverse/SimpleTraverser';
+
+import {SimpleTraverser, SimpleTraverserBreak} from 'hermes-parser';
 import {getCommentsForNode, setCommentsOnNode} from '../comments/comments';
 
 export type RemoveCommentMutation = $ReadOnly<{

tools/hermes-parser/js/hermes-transform/src/transform/mutations/ReplaceNode.js

@@ -12,11 +12,11 @@ import type {ESNode} from 'hermes-estree';
 import type {MutationContext} from '../MutationContext';
 import type {DetachedNode} from '../../detachedNode';
 
+import {getVisitorKeys, isNode} from 'hermes-parser';
 import {replaceInArray} from './utils/arrayUtils';
 import {moveCommentsToNewNode} from '../comments/comments';
 import {InvalidReplacementError} from '../Errors';
 import {getOriginalNode} from '../../detachedNode';
-import {getVisitorKeys, isNode} from '../../getVisitorKeys';
 
 export type ReplaceNodeMutation = $ReadOnly<{
   type: 'replaceNode',

tools/hermes-parser/js/hermes-transform/src/transform/transform.js

@@ -14,9 +14,9 @@ import type {ESNode} from 'hermes-estree';
 import type {Visitor} from '../traverse/traverse';
 import type {TransformContextAdditions} from './TransformContext';
 
+import {SimpleTraverser} from 'hermes-parser';
 import * as prettier from 'prettier';
 import {getTransformedAST} from './getTransformedAST';
-import {SimpleTraverser} from '../traverse/SimpleTraverser';
 
 export type TransformVisitor = Visitor<TransformContextAdditions>;
 

tools/hermes-parser/js/hermes-transform/src/traverse/traverse.js

@@ -15,7 +15,7 @@ import type {EmitterListener} from './SafeEmitter';
 import {codeFrameColumns} from '@babel/code-frame';
 import {NodeEventGenerator} from './NodeEventGenerator';
 import {SafeEmitter} from './SafeEmitter';
-import {SimpleTraverser} from './SimpleTraverser';
+import {SimpleTraverser} from 'hermes-parser';
 
 export type TraversalContextBase = $ReadOnly<{
   /**
@@ -81,11 +81,9 @@ export function traverseWithContext<T = TraversalContextBase>(
 
   let currentNode: ESNode = ast;
 
-  // set parent pointers and build up the traversal queue
+  // build up the traversal queue
   SimpleTraverser.traverse(ast, {
-    enter(node, parent) {
-      // $FlowExpectedError[cannot-write] - hermes doesn't set this
-      node.parent = parent;
+    enter(node) {
       nodeQueue.push({isEntering: true, node});
     },
     leave(node) {