Merge pull request #25124 from backstage/camilaibs/nbs10-return-null-from-extension-point-t-prop

[NBS1.0] Set `ExtensionPoint.T` to null in realtime test environment

.changeset/calm-files-sort.md

@@ -0,0 +1,5 @@
+---
+'@backstage/backend-plugin-api': patch
+---
+
+In tests, return `null` rather than throwing an error when trying to get the `ExtensionPoint.T` property, so that tests asserting the property are not easily broken.

packages/backend-plugin-api/src/wiring/factories.test.ts

@@ -26,7 +26,7 @@ describe('createExtensionPoint', () => {
     const extensionPoint = createExtensionPoint({ id: 'x' });
     expect(extensionPoint).toBeDefined();
     expect(extensionPoint.id).toBe('x');
-    expect(() => extensionPoint.T).toThrow();
+    expect(() => extensionPoint.T).not.toThrow();
     expect(String(extensionPoint)).toBe('extensionPoint{x}');
   });
 });

packages/backend-plugin-api/src/wiring/factories.ts

@@ -51,6 +51,10 @@ export function createExtensionPoint<T>(
   return {
     id: options.id,
     get T(): T {
+      if (process.env.NODE_ENV === 'test') {
+        // Avoid throwing errors so tests asserting extensions' properties cannot be easily broken
+        return null as T;
+      }
       throw new Error(`tried to read ExtensionPoint.T of ${this}`);
     },
     toString() {