fix: use older webpack-sources for WP4 and built-in one for WP5 (#300)

package.json

@@ -36,14 +36,14 @@
 		"json5": "^2.2.0",
 		"loader-utils": "^2.0.0",
 		"tapable": "^2.2.0",
-		"webpack-sources": "^2.2.0"
+		"webpack-sources": "^1.4.3"
 	},
 	"devDependencies": {
 		"@pvtnbr/eslint-config": "^0.33.0",
 		"@types/loader-utils": "^2.0.3",
 		"@types/node": "^18.11.18",
 		"@types/webpack": "^4.41.33",
-		"@types/webpack-sources": "^3.2.0",
+		"@types/webpack-sources": "^0.1.9",
 		"css-loader": "^5.2.7",
 		"eslint": "^8.31.0",
 		"manten": "^0.6.0",

src/minify-plugin.ts

@@ -1,5 +1,8 @@
 import { transform as defaultEsbuildTransform } from 'esbuild';
-import { RawSource, SourceMapSource } from 'webpack-sources';
+import {
+	RawSource as WP4RawSource,
+	SourceMapSource as WP4SourceMapSource,
+} from 'webpack-sources';
 import webpack from 'webpack';
 import type {
 	SyncHook, SyncBailHook, AsyncSeriesHook, HookMap,
@@ -107,7 +110,13 @@ class ESBuildMinifyPlugin {
 	private async transformAssets(
 		compilation: Compilation,
 	): Promise<void> {
-		const { options: { devtool } } = compilation.compiler;
+		const { compiler } = compilation;
+		const { options: { devtool } } = compiler;
+
+		// @ts-expect-error Only exists on Webpack 5
+		const sources = compiler.webpack?.sources;
+		const SourceMapSource = (sources ? sources.SourceMapSource : WP4SourceMapSource);
+		const RawSource = (sources ? sources.RawSource : WP4RawSource);
 
 		const sourcemap = (
 			// TODO: drop support for esbuild sourcemap in future so it all goes through WP API