allow default vendors splitChunk setting to reuse existing chunks

this allows the user to specify chunk names

lib/WebpackOptionsDefaulter.js

@@ -403,6 +403,7 @@ class WebpackOptionsDefaulter extends OptionsDefaulter {
 		});
 		this.set("optimization.splitChunks.cacheGroups.defaultVendors", {
 			idHint: "vendors",
+			reuseExistingChunk: true,
 			test: NODE_MODULES_REGEXP,
 			priority: -10
 		});

test/__snapshots__/StatsTestCases.test.js.snap

@@ -3126,6 +3126,24 @@ chunk main.js (main) 147 bytes (javascript) 4.84 KiB (runtime) >{async-a}< >{asy
      + 6 hidden root modules"
 `;
 
+exports[`StatsTestCases should print correct stats for split-chunks-chunk-name 1`] = `
+"Entrypoint main = default/main.js
+chunk default/main.js (main) 192 bytes (javascript) 4.89 KiB (runtime) >{334}< >{709}< >{794}< [entry] [rendered]
+    > ./ main
+ ./index.js 192 bytes [built]
+     + 6 hidden chunk modules
+chunk default/async-b.js (async-b) (id hint: vendors) 122 bytes <{179}> [rendered] reused as split chunk (cache group: defaultVendors)
+    > b ./index.js 2:0-45
+ ./node_modules/b.js 122 bytes [built]
+chunk default/async-c-1.js (async-c-1) (id hint: vendors) 122 bytes <{179}> [rendered] reused as split chunk (cache group: defaultVendors)
+    > c ./index.js 3:0-47
+    > c ./index.js 4:0-47
+ ./node_modules/c.js 122 bytes [built]
+chunk default/async-a.js (async-a) 20 bytes <{179}> [rendered]
+    > a ./index.js 1:0-45
+ ./node_modules/a.js 20 bytes [built]"
+`;
+
 exports[`StatsTestCases should print correct stats for split-chunks-combinations 1`] = `
 "Entrypoint main = main.js
 chunk async-d.js (async-d) 101 bytes <{179}> [rendered]

test/statsCases/split-chunks-chunk-name/index.js

@@ -0,0 +1,4 @@
+import(/* webpackChunkName: "async-a" */ "a");
+import(/* webpackChunkName: "async-b" */ "b");
+import(/* webpackChunkName: "async-c-1" */ "c");
+import(/* webpackChunkName: "async-c-2" */ "c");

test/statsCases/split-chunks-chunk-name/node_modules/a.js

@@ -0,0 +1 @@
+export default "a";

test/statsCases/split-chunks-chunk-name/node_modules/b.js

@@ -0,0 +1,3 @@
+export default "b";
+// content content content content content content
+// content content content content content content

test/statsCases/split-chunks-chunk-name/node_modules/c.js

@@ -0,0 +1,3 @@
+export default "c";
+// content content content content content content
+// content content content content content content

test/statsCases/split-chunks-chunk-name/webpack.config.js

@@ -0,0 +1,27 @@
+const stats = {
+	hash: false,
+	timings: false,
+	builtAt: false,
+	assets: false,
+	chunks: true,
+	chunkRelations: true,
+	chunkModules: true,
+	chunkOrigins: true,
+	entrypoints: true,
+	modules: false
+};
+module.exports = {
+	mode: "production",
+	entry: {
+		main: "./"
+	},
+	output: {
+		filename: "default/[name].js"
+	},
+	optimization: {
+		splitChunks: {
+			minSize: 100
+		}
+	},
+	stats
+};