Avoid building the template compiler cache key repeatedly

lib/template-compiler-plugin.js

@@ -1,6 +1,5 @@
 'use strict';
 
-const fs = require('fs');
 const path = require('path');
 const utils = require('./utils');
 const Filter = require('broccoli-persistent-filter');
@@ -105,20 +104,16 @@ class TemplateCompiler extends Filter {
     return strippedOptions;
   }
 
-  _templateCompilerContents() {
-    if (this.options.templateCompilerPath) {
-      return fs.readFileSync(this.options.templateCompilerPath, { encoding: 'utf8' });
-    } else {
-      return '';
-    }
-  }
-
   optionsHash() {
     if (!this._optionsHash) {
+      let templateCompilerCacheKey = utils.getTemplateCompilerCacheKey(
+        this.options.templateCompilerPath
+      );
+
       this._optionsHash = crypto
         .createHash('md5')
         .update(stringify(this._buildOptionsForHash()), 'utf8')
-        .update(stringify(this._templateCompilerContents()), 'utf8')
+        .update(templateCompilerCacheKey, 'utf8')
         .digest('hex');
     }
 

lib/utils.js

@@ -262,10 +262,20 @@ function setup(pluginInfo, options) {
   return plugin;
 }
 
-function makeCacheKey(templateCompilerPath, pluginInfo, extra) {
+function getTemplateCompilerCacheKey(templateCompilerPath) {
   let templateCompilerFullPath = require.resolve(templateCompilerPath);
-  let { templateCompilerCacheKey } = TemplateCompilerCache.get(templateCompilerFullPath);
+  let cacheData = TemplateCompilerCache.get(templateCompilerFullPath);
+
+  if (cacheData === undefined) {
+    getTemplateCompiler(templateCompilerFullPath);
+    cacheData = TemplateCompilerCache.get(templateCompilerFullPath);
+  }
+
+  return cacheData.templateCompilerCacheKey;
+}
 
+function makeCacheKey(templateCompilerPath, pluginInfo, extra) {
+  let templateCompilerCacheKey = getTemplateCompilerCacheKey(templateCompilerPath);
   let cacheItems = [templateCompilerCacheKey, extra].concat(pluginInfo.cacheKeys.sort());
 
   // extra may be undefined
@@ -347,4 +357,5 @@ module.exports = {
   isInlinePrecompileBabelPluginRegistered,
   buildParalleizedBabelPlugin,
   getTemplateCompiler,
+  getTemplateCompilerCacheKey,
 };

node-tests/addon-test.js

@@ -77,6 +77,7 @@ describe('ember-cli-htmlbars addon', function () {
         let htmlbarsOptions = {
           isHTMLBars: true,
           templateCompiler: require('ember-source/dist/ember-template-compiler.js'),
+          templateCompilerPath: require.resolve('ember-source/dist/ember-template-compiler.js'),
         };
 
         subject = this.addon.transpileTree(input.path(), htmlbarsOptions);

node-tests/ast_plugins_test.js

@@ -26,6 +26,7 @@ describe('AST plugins', function () {
       htmlbarsOptions = {
         isHTMLBars: true,
         templateCompiler: templateCompiler,
+        templateCompilerPath: require.resolve('ember-source/dist/ember-template-compiler.js'),
       };
     })
   );

node-tests/template_compiler_test.js

@@ -41,6 +41,7 @@ describe('TemplateCompiler', function () {
         ast: [],
       },
       templateCompiler: require('ember-source/dist/ember-template-compiler.js'),
+      templateCompilerPath: require.resolve('ember-source/dist/ember-template-compiler.js'),
     };
 
     htmlbarsPrecompile = htmlbarsOptions.templateCompiler.precompile;