From d8924c62303928b54cffc290f84423b23a468976 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jakub=20Roma=C5=84czyk?= <jakub.romanczyk@callstack.com>
Date: Fri, 2 Aug 2024 15:47:35 +0200
Subject: [PATCH] fix: infinite loop when traversing the chunk graph in
 `OutputPlugin` (#679)

* fix: ifinite recursion in output plugin

* chore: add changeset

* refactor: typings
---
 .changeset/fast-cats-think.md                    |  5 +++++
 .../repack/src/webpack/plugins/OutputPlugin.ts   | 16 ++++++++++------
 2 files changed, 15 insertions(+), 6 deletions(-)
 create mode 100644 .changeset/fast-cats-think.md

diff --git a/.changeset/fast-cats-think.md b/.changeset/fast-cats-think.md
new file mode 100644
index 000000000..d4f03c283
--- /dev/null
+++ b/.changeset/fast-cats-think.md
@@ -0,0 +1,5 @@
+---
+"@callstack/repack": patch
+---
+
+fix infinite loop when traversing the chunk graph in OutputPlugin
diff --git a/packages/repack/src/webpack/plugins/OutputPlugin.ts b/packages/repack/src/webpack/plugins/OutputPlugin.ts
index 3eb697197..dfdf37bcd 100644
--- a/packages/repack/src/webpack/plugins/OutputPlugin.ts
+++ b/packages/repack/src/webpack/plugins/OutputPlugin.ts
@@ -4,6 +4,7 @@ import { Rule, WebpackPlugin } from '../../types';
 import { AssetsCopyProcessor } from './utils/AssetsCopyProcessor';
 import { AuxiliaryAssetsCopyProcessor } from './utils/AuxiliaryAssetsCopyProcessor';
 
+type ChunkId = Exclude<webpack.StatsChunk['id'], undefined>;
 /**
  * Matching options to check if given {@link DestinationConfig} should be used.
  */
@@ -227,19 +228,22 @@ export class OutputPlugin implements WebpackPlugin {
 
     const getAllInitialChunks = (
       chunk: webpack.StatsChunk,
-      chunks: Map<string | number, webpack.StatsChunk>
+      chunks: Map<ChunkId, webpack.StatsChunk>,
+      visited = new Set<ChunkId>()
     ): Array<webpack.StatsChunk> => {
-      if (!chunk.parents?.length) {
-        return [chunk];
+      // Prevent cycles when traversing chunks graph
+      if (visited.has(chunk.id!)) {
+        return [];
       }
+      visited.add(chunk.id!);
 
-      // Chunk might reference itself as a parent (and/or child)
-      if (chunk.parents.length === 1 && chunk.parents[0] === chunk.id) {
+      // If chunk has no parents, it's an initial chunk
+      if (!chunk.parents?.length) {
         return [chunk];
       }
 
       return chunk.parents.flatMap((parent) => {
-        return getAllInitialChunks(chunks.get(parent)!, chunks);
+        return getAllInitialChunks(chunks.get(parent)!, chunks, visited);
       });
     };