fix: html-webpack-plugin child compiler chunk id (#56)

* fix: html-webpack-plugin child compiler. fixes #55

* chore: remove markdown-toc

the author of markdown-toc also owns remarkable, and has a policy
of not updating for reported security issues.
see: jonschlinkert/remarkable#312

lib/hmr-plugin.js

@@ -41,10 +41,16 @@ const hookPlugin = (compiler) => {
 
   compiler.hooks.compilation.tap('wps', (compilation) => {
     const { mainTemplate } = compilation;
-    const { assetPath, hotBootstrap } = mainTemplate.hooks;
+    const { assetPath, hashForChunk, hotBootstrap } = mainTemplate.hooks;
     const { additionalChunkAssets } = compilation.hooks;
     let currentChunk;
 
+    // fixes #55. html-webpack-plugin uses a child compiler which alters the order of chunk
+    // processing, calling assetPath before hotBootstrap.
+    hashForChunk.tap('wps', (hash, chunk) => {
+      currentChunk = chunk;
+    });
+
     intercept(hotBootstrap, 'JsonpMainTemplatePlugin', (hook, ogFn) => {
       hook.fn = (source, chunk, hash) => {
         currentChunk = chunk;
@@ -57,6 +63,12 @@ const hookPlugin = (compiler) => {
       const mainTest = `"${mainPlaceholder}"`;
 
       hook.fn = (path, data) => {
+        // html-webpack-plugin doesn't call the same hooks that normal assets do. currentChunk will
+        // always be undefined for its files.
+        if (!currentChunk) {
+          return ogFn(path, data);
+        }
+
         const { hotUpdateChunkFilename, hotUpdateMainFilename } = compiler.options.output;
 
         if (path === chunkTest) {
@@ -72,6 +84,7 @@ const hookPlugin = (compiler) => {
             oldHotUpdateMainFilename: hotUpdateMainFilename
           });
         }
+
         return ogFn(path, data);
       };
     });