docs: document moduleResolution bundler change in v20 update guide

erkamyaman · amishne · commit 67a5f00cd8c2 · 2026-04-27T17:06:35.000-07:00
The v20 update guide doesn't flag that `ng update` switches
`moduleResolution` to `'bundler'`. Add a checklist item so manual
upgrades don't miss it.
diff --git a/adev/src/app/features/update/recommendations.ts b/adev/src/app/features/update/recommendations.ts
@@ -2703,6 +2703,14 @@ export const RECOMMENDATIONS: Step[] = [
     action:
       "Upgrade your project's TypeScript version to at least 5.8 before upgrading to Angular v20 to ensure compatibility.",
   },
+  {
+    possibleIn: 2000,
+    necessaryAsOf: 2000,
+    level: ApplicationComplexity.Medium,
+    step: '20.0.0_set_moduleResolution_to_bundler',
+    action:
+      "Set `moduleResolution` to `'bundler'` in your `tsconfig.json`. Angular CLI's `ng update` migration applies this change automatically; if you upgrade manually or override the option in a base tsconfig, set it explicitly so imports of secondary entry-points such as `@angular/core/rxjs-interop` continue to resolve correctly.",
+  },
   {
     possibleIn: 2000,
     necessaryAsOf: 2000,
