Fix Metro Server crash on empty or undefined symbolication payload

[vijaykumawat2001]

Hi! 👋

Firstly, thanks for your work on this project! 🙂

Today I used patch-package to patch metro@0.81.5 for the project I'm working on.

Here is the diff that solved my problem:

diff --git a/node_modules/metro/src/Server.js b/node_modules/metro/src/Server.js
index ec933c0..2d10cd8 100644
--- a/node_modules/metro/src/Server.js
+++ b/node_modules/metro/src/Server.js
@@ -975,7 +975,17 @@ class Server {
       );
       debug("Start symbolication");
       const body = await req.rawBody;
-      const parsedBody = JSON.parse(body);
+      let parsedBody;
+      try {
+        if (typeof body !== 'string' || body.trim() === '' || body.trim() === 'undefined') {
+          throw new SyntaxError('Invalid symbolication payload');
+        }
+        parsedBody = JSON.parse(body);
+      } catch (e) {
+        res.statusCode = 400;
+        res.end(JSON.stringify({error: 'Invalid symbolication payload'}));
+        return;
+      }
       const rewriteAndNormalizeStackFrame = (frame, lineNumber) => {
         invariant(
           frame != null && typeof frame === "object",

This issue body was partially generated by patch-package.

[kitten]

This is obsolete, it seems, as the entire function body is now guarded by a try-catch: https://github.com/facebook/metro/blob/47131bc1597fd635d20f7997804bc77399ff9e9b/packages/metro/src/Server.js#L1431-L1446