fix(index, loader): Fixing HMR from assorted config build, exported loader

In rare cases, on large project such as React Static, webpack configs can end up using random series
of keys and structures. In this case, there was a loader key inside a oneOf key, causing the
recursive lookup to fail. Also exported the hot loader directly for hopeless cases

fix faceyspacey#110

Author: ScriptedAlchemy

src/index.js

@@ -168,7 +168,7 @@ class ExtractCssChunks {
         compiler.options.module.rules = this.updateWebpackConfig(compiler.options.module.rules);
       }
     } catch (e) {
-      throw new Error(`Something went wrong: contact the author: ${JSON.stringify(e)}`);
+      throw new Error(e);
     }
 
     compiler.hooks.thisCompilation.tap(pluginName, (compilation) => {
@@ -406,34 +406,47 @@ class ExtractCssChunks {
     });
   }
 
-  traverseDepthFirst(root, visit) {
-    let nodesToVisit = [root];
+  searchObject(node) {
+    if (!node) {
+      return false;
+    }
 
-    while (nodesToVisit.length > 0) {
-      const currentNode = nodesToVisit.shift();
+    if (typeof node === 'string' && node === pluginName) {
+      return true;
+    }
 
-      if (currentNode !== null && typeof currentNode === 'object') {
-        const children = Object.values(currentNode);
-        nodesToVisit = [...children, ...nodesToVisit];
+    return node.some((l) => {
+      const needle = l.loader || l;
+      if (needle === pluginName) {
+        return true;
       }
-
-      visit(currentNode);
-    }
+      return needle.includes(pluginName);
+    });
   }
 
   updateWebpackConfig(rulez) {
+    let isExtract = null;
     return rulez.reduce((rules, rule) => {
-      this.traverseDepthFirst(rule, (node) => {
-        if (node && node.use && Array.isArray(node.use)) {
-          const isMiniCss = node.use.some((l) => {
-            const needle = l.loader || l;
-            return needle.includes(pluginName);
-          });
-          if (isMiniCss) {
-            node.use.unshift(this.hotLoaderObject);
-          }
+      if (rule.oneOf) {
+        rule.oneOf = this.updateWebpackConfig(rule.oneOf);
+      }
+
+      // redundant but works
+      if (rule.loader && Array.isArray(rule.loader)) {
+        isExtract = this.searchObject(rule.loader);
+
+        if (isExtract) {
+          rule.loader.unshift(hotLoader);
         }
-      });
+      }
+
+      if (rule.use && Array.isArray(rule.use)) {
+        isExtract = this.searchObject(rule.use);
+
+        if (isExtract) {
+          rule.use.unshift(hotLoader);
+        }
+      }
       rules.push(rule);
 
       return rules;
@@ -592,5 +605,6 @@ class ExtractCssChunks {
 }
 
 ExtractCssChunks.loader = require.resolve('./loader');
+ExtractCssChunks.hotLoader = require.resolve('./hotLoader');
 
 export default ExtractCssChunks;