BrowserAnimationsModule vs NoopAnimationsModule: Angular Material animation retention in production builds

Answer

Angular Material components such as MatMenu and MatTooltip retain their animations in a production build as long as the real animation engine is provided at the root injector (i.e., BrowserAnimationsModule in an NgModule app or provideAnimations() in a standalone bootstrap). Replacing that provider with NoopAnimationsModule or provideNoopAnimations() disables all Material animations globally.

Confirmed facts

1. BrowserAnimationsModule registers the actual @angular/animations engine via the ANIMATION_MODULE_TYPE token.
2. NoopAnimationsModule registers a no‑op engine that resolves animation triggers instantly, which removes all transitions.
3. Angular Material animation triggers are defined inside the component libraries; they use whatever engine is injected at application start, so a standard production build with the real provider keeps the animations intact.
4. The Angular CLI’s default optimization flags (scriptsOptimization, stylesOptimization, buildOptimizer) do not selectively strip animation metadata; they only affect code size and dead‑code elimination.

Likely explanation for missing animations

If animations disappear after ng build --configuration production, the most common cause is that the real animation provider is absent or has been conditionally swapped for the no‑op provider in the production configuration (e.g., a custom file replacement, a webpack plugin, or an environment‑specific import).

Steps to verify and fix

1. Check the root module (AppModule) or the standalone bootstrap (main.ts) for the import of BrowserAnimationsModule (or call to provideAnimations()). Ensure it is not guarded by an environment check that imports NoopAnimationsModule instead.
2. Confirm that angular.json uses the default builder (@angular-devkit/build-angular:browser) and that no custom builder or fileReplacements swaps the animation module between dev and prod.
3. Run a local production build and test a simple animation (e.g., a *fadeIn trigger on a div). If that works, the build pipeline is preserving animations and the issue is isolated to your component‑level provider configuration.
4. If the test animation still does not run, inspect the produced bundle for any accidental inclusion of NoopAnimationsModule or missing BrowserAnimationsModule (look for the provider names in the generated main.js).

Missing diagnostic detail

Can you confirm whether your application boots via an NgModule (AppModule) or uses standalone bootstrapApplication, and whether there is any environment‑specific import that conditionally swaps BrowserAnimationsModule for NoopAnimationsModule?