From 29a4738cd90d324006b260360db735c907b745bd Mon Sep 17 00:00:00 2001
From: Vincenzo Scamporlino <vincenzos@spotify.com>
Date: Tue, 15 Aug 2023 16:28:10 +0200
Subject: [PATCH] backend-test-utils: detect internal features

Signed-off-by: Vincenzo Scamporlino <vincenzos@spotify.com>
---
 .../src/next/wiring/TestBackend.ts            | 23 ++++++++++++++-----
 1 file changed, 17 insertions(+), 6 deletions(-)

diff --git a/packages/backend-test-utils/src/next/wiring/TestBackend.ts b/packages/backend-test-utils/src/next/wiring/TestBackend.ts
index 13c05eb61c..97da3543ae 100644
--- a/packages/backend-test-utils/src/next/wiring/TestBackend.ts
+++ b/packages/backend-test-utils/src/next/wiring/TestBackend.ts
@@ -103,13 +103,16 @@ function createExtensionPointTestModules(
         `Failed to add feature, invalid type '${feature.$$type}'`,
       );
     }
-    const internalFeature = feature as InternalBackendFeature;
-    if (internalFeature.version !== 'v1') {
-      throw new Error(
-        `Failed to add feature, invalid version '${internalFeature.version}'`,
-      );
+
+    if (isInternalBackendFeature(feature)) {
+      if (feature.version !== 'v1') {
+        throw new Error(
+          `Failed to add feature, invalid version '${feature.version}'`,
+        );
+      }
+      return feature.getRegistrations();
     }
-    return internalFeature.getRegistrations();
+    return [];
   });
 
   const extensionPointMap = new Map(
@@ -287,3 +290,11 @@ function registerTestHooks() {
 }
 
 registerTestHooks();
+
+function isInternalBackendFeature(
+  feature: BackendFeature,
+): feature is InternalBackendFeature {
+  return (
+    typeof (feature as InternalBackendFeature).getRegistrations === 'function'
+  );
+}