From 60d4605173c281bd705cedbb03f19d239a2ef76e Mon Sep 17 00:00:00 2001
From: Pascal Corpet <pascal@bayesimpact.org>
Date: Mon, 8 Mar 2021 09:06:04 +0100
Subject: [PATCH 1/3] fix types: accept a readonly array for configuration
 options

---
 lib/webpack.js | 14 ++++++++------
 types.d.ts     |  4 ++--
 2 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/lib/webpack.js b/lib/webpack.js
index 810bb960f61..12ebd78f798 100644
--- a/lib/webpack.js
+++ b/lib/webpack.js
@@ -33,7 +33,7 @@ const validateSchema = require("./validateSchema");
  */
 
 /**
- * @param {WebpackOptions[]} childOptions options array
+ * @param {ReadonlyArray<WebpackOptions>} childOptions options array
  * @param {MultiCompilerOptions} options options
  * @returns {MultiCompiler} a multi-compiler
  */
@@ -89,14 +89,14 @@ const createCompiler = rawOptions => {
 
 /**
  * @callback WebpackFunctionMulti
- * @param {WebpackOptions[] & MultiCompilerOptions} options options objects
+ * @param {ReadonlyArray<WebpackOptions> & MultiCompilerOptions} options options objects
  * @param {Callback<MultiStats>=} callback callback
  * @returns {MultiCompiler} the multi compiler object
  */
 
 const webpack = /** @type {WebpackFunctionSingle & WebpackFunctionMulti} */ (
 	/**
-	 * @param {WebpackOptions | (WebpackOptions[] & MultiCompilerOptions)} options options
+	 * @param {WebpackOptions | (ReadonlyArray<WebpackOptions> & MultiCompilerOptions)} options options
 	 * @param {Callback<Stats> & Callback<MultiStats>=} callback callback
 	 * @returns {Compiler | MultiCompiler}
 	 */
@@ -114,10 +114,12 @@ const webpack = /** @type {WebpackFunctionSingle & WebpackFunctionMulti} */ (
 				watch = options.some(options => options.watch);
 				watchOptions = options.map(options => options.watchOptions || {});
 			} else {
+				/** @type {WebpackOptions} */
+				const webpackOptions = /** @type {WebpackOptions} */ options;
 				/** @type {Compiler} */
-				compiler = createCompiler(options);
-				watch = options.watch;
-				watchOptions = options.watchOptions || {};
+				compiler = createCompiler(webpackOptions);
+				watch = webpackOptions.watch;
+				watchOptions = webpackOptions.watchOptions || {};
 			}
 			return { compiler, watch, watchOptions };
 		};
diff --git a/types.d.ts b/types.d.ts
index bccd6f642a2..6fa647b36ef 100644
--- a/types.d.ts
+++ b/types.d.ts
@@ -11169,14 +11169,14 @@ declare function exports(
 	callback?: CallbackWebpack<Stats>
 ): Compiler;
 declare function exports(
-	options: Configuration[] & MultiCompilerOptions,
+	options: ReadonlyArray<Configuration> & MultiCompilerOptions,
 	callback?: CallbackWebpack<MultiStats>
 ): MultiCompiler;
 declare namespace exports {
 	export const webpack: {
 		(options: Configuration, callback?: CallbackWebpack<Stats>): Compiler;
 		(
-			options: Configuration[] & MultiCompilerOptions,
+			options: ReadonlyArray<Configuration> & MultiCompilerOptions,
 			callback?: CallbackWebpack<MultiStats>
 		): MultiCompiler;
 	};

From cc1b41420c84752c461664c741a971193bc8147e Mon Sep 17 00:00:00 2001
From: Pascal Corpet <pcorpet@users.noreply.github.com>
Date: Thu, 1 Apr 2021 23:52:21 +0200
Subject: [PATCH 2/3] Update lib/webpack.js

Co-authored-by: Tobias Koppers <tobias.koppers@googlemail.com>
---
 lib/webpack.js | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/lib/webpack.js b/lib/webpack.js
index 12ebd78f798..a5d4bffc9e4 100644
--- a/lib/webpack.js
+++ b/lib/webpack.js
@@ -114,8 +114,7 @@ const webpack = /** @type {WebpackFunctionSingle & WebpackFunctionMulti} */ (
 				watch = options.some(options => options.watch);
 				watchOptions = options.map(options => options.watchOptions || {});
 			} else {
-				/** @type {WebpackOptions} */
-				const webpackOptions = /** @type {WebpackOptions} */ options;
+				const webpackOptions = /** @type {WebpackOptions} */ (options);
 				/** @type {Compiler} */
 				compiler = createCompiler(webpackOptions);
 				watch = webpackOptions.watch;

From 5f7394b76f7811af9d2aa20acab696321987826b Mon Sep 17 00:00:00 2001
From: Tobias Koppers <tobias.koppers@googlemail.com>
Date: Tue, 18 May 2021 17:10:36 +0200
Subject: [PATCH 3/3] fix type error

---
 lib/webpack.js | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/lib/webpack.js b/lib/webpack.js
index 8368b444ee8..82f0c754c1f 100644
--- a/lib/webpack.js
+++ b/lib/webpack.js
@@ -115,7 +115,10 @@ const webpack = /** @type {WebpackFunctionSingle & WebpackFunctionMulti} */ (
 			let watchOptions;
 			if (Array.isArray(options)) {
 				/** @type {MultiCompiler} */
-				compiler = createMultiCompiler(options, options);
+				compiler = createMultiCompiler(
+					options,
+					/** @type {MultiCompilerOptions} */ (options)
+				);
 				watch = options.some(options => options.watch);
 				watchOptions = options.map(options => options.watchOptions || {});
 			} else {