From afe1817f5178bab57c052bc5875b71e77be86850 Mon Sep 17 00:00:00 2001
From: Konstantin Lopyrev <klopyrev@mail.tradingview.com>
Date: Thu, 5 Apr 2018 12:41:35 +0300
Subject: [PATCH] Duck typing instead of instanceof

---
 index.js | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/index.js b/index.js
index 713a8ed6..bb4bdf39 100644
--- a/index.js
+++ b/index.js
@@ -355,7 +355,14 @@ function getPath(compilation, source, chunk) {
 }
 
 function isChunk(chunk, error) {
-	if (!(chunk instanceof Chunk)) {
+	if (
+		!chunk ||
+		(
+			!chunk.modulesIterable &&
+			!chunk.forEachModule &&
+			!chunk.modules
+		)
+	) {
 		throw new Error(typeof error === 'string' ? error : 'chunk is not an instance of Chunk');
 	}