Uses a singleton cache to store the compilation stats (#723)

* Uses a singleton cache to store the compilation stats

* Use compilation.hash as the index for the cached stats

* Remove calls to compilation.getStats().toJson() because it is expensive and we actually don't need it

* Remove debugger statement

* Make changes compatible with webpack2

* Use json representation for chunks to avoid breaking `chunksSortMode`

index.js

@@ -252,7 +252,7 @@ HtmlWebpackPlugin.prototype.executeTemplate = function (templateFunction, chunks
     .then(function () {
       var templateParams = {
         compilation: compilation,
-        webpack: compilation.getStats().toJson(),
+        webpack: compilation.getStats(),
         webpackConfig: compilation.options,
         htmlWebpackPlugin: {
           files: assets,
@@ -360,7 +360,11 @@ HtmlWebpackPlugin.prototype.filterChunks = function (chunks, includedChunks, exc
       return false;
     }
     // Skip if the chunk should be lazy loaded
-    if (!chunk.initial) {
+    if (typeof chunk.isInitial === 'function') {
+      if (!chunk.isInitial()) {
+        return false;
+      }
+    } else if (!chunk.initial) {
       return false;
     }
     // Skip if the chunks should be filtered and the given chunk was not added explicity
@@ -384,12 +388,12 @@ HtmlWebpackPlugin.prototype.isHotUpdateCompilation = function (assets) {
 
 HtmlWebpackPlugin.prototype.htmlWebpackPluginAssets = function (compilation, chunks) {
   var self = this;
-  var webpackStatsJson = compilation.getStats().toJson();
+  var compilationHash = compilation.hash;
 
   // Use the configured public path or build a relative path
   var publicPath = typeof compilation.options.output.publicPath !== 'undefined'
     // If a hard coded public path exists use it
-    ? compilation.mainTemplate.getPublicPath({hash: webpackStatsJson.hash})
+    ? compilation.mainTemplate.getPublicPath({hash: compilationHash})
     // If no public path was set get a relative url path
     : path.relative(path.resolve(compilation.options.output.path, path.dirname(self.childCompilationOutputName)), compilation.options.output.path)
       .split(path.sep).join('/');
@@ -415,8 +419,8 @@ HtmlWebpackPlugin.prototype.htmlWebpackPluginAssets = function (compilation, chu
 
   // Append a hash for cache busting
   if (this.options.hash) {
-    assets.manifest = self.appendHash(assets.manifest, webpackStatsJson.hash);
-    assets.favicon = self.appendHash(assets.favicon, webpackStatsJson.hash);
+    assets.manifest = self.appendHash(assets.manifest, compilationHash);
+    assets.favicon = self.appendHash(assets.favicon, compilationHash);
   }
 
   for (var i = 0; i < chunks.length; i++) {
@@ -433,7 +437,7 @@ HtmlWebpackPlugin.prototype.htmlWebpackPluginAssets = function (compilation, chu
     // Append a hash for cache busting
     if (this.options.hash) {
       chunkFiles = chunkFiles.map(function (chunkFile) {
-        return self.appendHash(chunkFile, webpackStatsJson.hash);
+        return self.appendHash(chunkFile, compilationHash);
       });
     }