From 8672129146f992027bce863dc530d9fa3140458d Mon Sep 17 00:00:00 2001
From: Lukas Taegert-Atkinson <lukas.taegert-atkinson@tngtech.com>
Date: Sat, 5 Nov 2022 21:18:26 +0100
Subject: [PATCH] Extract helper

---
 src/utils/chunkAssignment.ts |  8 +-------
 src/utils/iterators.ts       | 10 ++++++++++
 2 files changed, 11 insertions(+), 7 deletions(-)
 create mode 100644 src/utils/iterators.ts

diff --git a/src/utils/chunkAssignment.ts b/src/utils/chunkAssignment.ts
index c456ad21f47..3186f6912a1 100644
--- a/src/utils/chunkAssignment.ts
+++ b/src/utils/chunkAssignment.ts
@@ -1,6 +1,7 @@
 import ExternalModule from '../ExternalModule';
 import Module from '../Module';
 import { getOrCreate } from './getOrCreate';
+import { concatLazy } from './iterators';
 import relativeId from './relativeId';
 import { timeEnd, timeStart } from './timers';
 
@@ -331,15 +332,8 @@ function mergeSignatures(sourceSignature: string, targetSignature: string): stri
 	return signature;
 }
 
-function* concatLazy<T>(...iterators: Iterable<T>[]) {
-	for (const iterator of iterators) {
-		yield* iterator;
-	}
-}
-
 // DEBUGGING HELPERS, REMOVED BY TREE-SHAKING
 /* eslint-disable @typescript-eslint/no-unused-vars */
-
 const relativeModuleId = (module: Module) => relativeId(module.id);
 
 const printModuleMap = (label: string, map: DependentModuleMap) =>
diff --git a/src/utils/iterators.ts b/src/utils/iterators.ts
new file mode 100644
index 00000000000..afbe9eb1850
--- /dev/null
+++ b/src/utils/iterators.ts
@@ -0,0 +1,10 @@
+/**
+ * Concatenate a number of iterables to a new iterable without fully evaluating
+ * their iterators. Useful when e.g. working with large sets or lists and when
+ * there is a chance that the iterators will not be fully exhausted.
+ */
+export function* concatLazy<T>(...iterables: Iterable<T>[]) {
+	for (const iterable of iterables) {
+		yield* iterable;
+	}
+}