Run the old preprocessor hack for older versions of embroider

index.js

@@ -5,6 +5,7 @@
 const Funnel = require('broccoli-funnel');
 const chalk = require('chalk');
 const BroccoliDebug = require('broccoli-debug');
+const VersionChecker = require('ember-cli-version-checker');
 const camelCase = require('camelcase');
 const { createHash } = require('crypto');
 const _ = require('lodash');
@@ -208,14 +209,28 @@ module.exports = {
   },
 
   setupPreprocessorRegistry(type, registry) {
-    // The canvas plugin should run on `self` and `parent`.
-    this._setupCanvasPlugin(registry);
+    let checker = new VersionChecker(this.project);
+    let embroider = checker.for('@embroider/core');
+
+    if (embroider.lt('2.0.0') && this.checkIfWillProbablyUseEmbroider()) {
+      // `type === 'self'` is broken in older Embroider versions. It doesn’t seem
+      // to correctly pass the plugins to `broccoli-babel-transpiler`. This works
+      // for some reason.
+      if (type === 'parent') {
+        this._setupCanvasPlugin(registry);
+        this._setupAddonPlugin(registry);
+        this._setupTreeshakerPlugin(registry);
+      }
+    } else {
+      // The canvas plugin should run on `self` and `parent`.
+      this._setupCanvasPlugin(registry);
 
-    if (type === 'self') {
-      // The addon plugin should run on `self`.
-      this._setupAddonPlugin(registry);
+      if (type === 'self') {
+        // The addon plugin should run on `self`.
+        this._setupAddonPlugin(registry);
 
-      this._setupTreeshakerPlugin(registry);
+        this._setupTreeshakerPlugin(registry);
+      }
     }
   },
 

package.json

@@ -51,6 +51,7 @@
     "ember-auto-import": "^2.6.3",
     "ember-cli-babel": "^7.26.11",
     "ember-cli-htmlbars": "^6.2.0",
+    "ember-cli-version-checker": "^5.1.2",
     "ember-concurrency": "^3.0.0",
     "ember-modifier": "^3.2.7",
     "lodash": "^4.17.21",