From b65e6fc58b8c9a35e2c2ea7d1952fc1499cef09b Mon Sep 17 00:00:00 2001
From: lauren <poteto@users.noreply.github.com>
Date: Mon, 6 Oct 2025 12:43:39 -0400
Subject: [PATCH] Revert [eprh] Remove hermes-parser (#34747)

Adds back HermesParser to eslint-plugin-react-hooks. There are still
[external users of
Flow](https://github.com/facebook/react/pull/34719#issuecomment-3368137743)
using the plugin, so we shouldn't break the plugin for them. However, we
still have the problem of double parsing: once from eslint (which we
discard) and then another via babel/hermes parser.

In the long run we should investigate a translation layer from estree to
babel (or alternatively, update the compiler to take estree as input).
But for now, I am reverting the PR.

This does mean that [Sandpack in
react.dev](https://github.com/reactjs/react.dev/blob/11cb6b591571caf5fa2a192117b6a6445c3f2027/src/components/MDX/Sandpack/runESLint.tsx#L31)
cannot update to the latest eprh as HermesParser does not appear to be
able to be run in a browser. I discovered this while trying to update
eprh on react.dev last week, but didn't investigate deeply. I'll need to
double check that again to find out more.
---
 .../eslint-plugin-react-hooks/package.json    |  1 +
 .../src/shared/RunReactCompiler.ts            | 31 ++++++++++++++-----
 2 files changed, 24 insertions(+), 8 deletions(-)

diff --git a/packages/eslint-plugin-react-hooks/package.json b/packages/eslint-plugin-react-hooks/package.json
index 557e48af65fcd..fdea39282033a 100644
--- a/packages/eslint-plugin-react-hooks/package.json
+++ b/packages/eslint-plugin-react-hooks/package.json
@@ -41,6 +41,7 @@
   "dependencies": {
     "@babel/core": "^7.24.4",
     "@babel/parser": "^7.24.4",
+    "hermes-parser": "^0.25.1",
     "zod": "^3.22.4 || ^4.0.0",
     "zod-validation-error": "^3.0.3 || ^4.0.0"
   },
diff --git a/packages/eslint-plugin-react-hooks/src/shared/RunReactCompiler.ts b/packages/eslint-plugin-react-hooks/src/shared/RunReactCompiler.ts
index 7755dbe947f4a..02fd68badf611 100644
--- a/packages/eslint-plugin-react-hooks/src/shared/RunReactCompiler.ts
+++ b/packages/eslint-plugin-react-hooks/src/shared/RunReactCompiler.ts
@@ -17,6 +17,7 @@ import BabelPluginReactCompiler, {
   LoggerEvent,
 } from 'babel-plugin-react-compiler';
 import type {SourceCode} from 'eslint';
+import * as HermesParser from 'hermes-parser';
 import {isDeepStrictEqual} from 'util';
 import type {ParseResult} from '@babel/parser';
 
@@ -113,14 +114,28 @@ function runReactCompilerImpl({
   }
 
   let babelAST: ParseResult<File> | null = null;
-  try {
-    babelAST = babelParse(sourceCode.text, {
-      sourceFilename: filename,
-      sourceType: 'unambiguous',
-      plugins: ['typescript', 'jsx'],
-    });
-  } catch (err: unknown) {
-    /* empty */
+
+  if (filename.endsWith('.tsx') || filename.endsWith('.ts')) {
+    try {
+      babelAST = babelParse(sourceCode.text, {
+        sourceFilename: filename,
+        sourceType: 'unambiguous',
+        plugins: ['typescript', 'jsx'],
+      });
+    } catch {
+      /* empty */
+    }
+  } else {
+    try {
+      babelAST = HermesParser.parse(sourceCode.text, {
+        babel: true,
+        enableExperimentalComponentSyntax: true,
+        sourceFilename: filename,
+        sourceType: 'module',
+      });
+    } catch {
+      /* empty */
+    }
   }
 
   if (babelAST != null) {