fix: handle functions as loaders

Do not break when searching through `use` or `loader` that is a function

Author: ScriptedAlchemy

package.json

@@ -1,6 +1,6 @@
 {
   "name": "extract-css-chunks-webpack-plugin",
-  "version": "3.2.0",
+  "version": "3.2.1-alpha.0",
   "author": "James Gillmore <james@faceyspacey.com>",
   "contributors": [
     "Zack Jackson <zack@ScriptedAlchemy.com> (https://github.com/ScriptedAlchemy)"

src/index.js

@@ -427,6 +427,9 @@ class ExtractCssChunks {
         if (node && node.use && Array.isArray(node.use)) {
           const isMiniCss = node.use.some((l) => {
             const needle = l.loader || l;
+            if (typeof l === 'function') {
+              return false;
+            }
             return needle.includes(pluginName);
           });
           if (isMiniCss) {
@@ -436,6 +439,9 @@ class ExtractCssChunks {
         if (node && node.loader && Array.isArray(node.loader)) {
           const isMiniCss = node.loader.some((l) => {
             const needle = l.loader || l;
+            if (typeof l === 'function') {
+              return false;
+            }
             return needle.includes(pluginName);
           });
           if (isMiniCss) {