keep the messier old parallelBabel hacks in order to keep working wit…

…h older htmlbars

packages/compat/src/prepare-htmlbars-ast-plugins.ts

@@ -1,7 +1,37 @@
 import type { Transform } from 'babel-plugin-ember-template-compilation';
+import { join } from 'path';
 
 export default function loadAstPlugins(registry: any): Transform[] {
-  let plugins = registry.load('htmlbars-ast-plugin').map((wrapper: any) => wrapper.plugin);
+  let wrappers = registry.load('htmlbars-ast-plugin');
+  for (let wrapper of wrappers) {
+    const { plugin, parallelBabel, baseDir, cacheKey } = wrapper;
+    if (plugin) {
+      // if the parallelBabel options were set on the wrapper, but not on the plugin, add it
+      if (parallelBabel && !plugin.parallelBabel) {
+        plugin.parallelBabel = {
+          requireFile: join(__dirname, 'htmlbars-unwrapper.js'),
+          buildUsing: 'unwrapPlugin',
+          params: parallelBabel,
+        };
+      }
+
+      // NOTE: `_parallelBabel` (not `parallelBabel`) is expected by broccoli-babel-transpiler
+      if (plugin.parallelBabel && !plugin._parallelBabel) {
+        plugin._parallelBabel = plugin.parallelBabel;
+      }
+
+      // if the baseDir is set on the wrapper, but not on the plugin, add it
+      if (baseDir && !plugin.baseDir) {
+        plugin.baseDir = baseDir;
+      }
+
+      // if the cacheKey is set on the wrapper, but not on the plugin, add it
+      if (cacheKey && !plugin.cacheKey) {
+        plugin.cacheKey = cacheKey;
+      }
+    }
+  }
+  let plugins = wrappers.map((wrapper: any) => wrapper.plugin);
   plugins.reverse();
   return plugins;
 }