Blog - Code-JS

Race Conditions in Angular: switchMap vs mergeMap vs concatMap vs exhaustMap [2026]

Lesson 10.6 of the Angular tutorial — fixing race conditions in async code: a decision table for switchMap, mergeMap, concatMap and exhaustMap with typeahead, save-button and upload-queue examples, stale-request cancellation in resource() and httpResource(), AbortController with fetch, and untracked() for effect cycles.

Race Conditions in Angular: switchMap vs mergeMap vs concatMap vs exhaustMap [2026] Read More »

Finding Subscription and Effect Leaks in Angular: A Codebase Audit [2026]

Leave a Comment / Angular / Code-JS

Lesson 10.5 of the Angular tutorial — a code-level leak audit: searches that find risky subscriptions, timers and listeners, retrofitting takeUntilDestroyed() and toSignal(), DestroyRef.onDestroy cleanup, onCleanup in effects, and lint rules that keep leaks out.

Finding Subscription and Effect Leaks in Angular: A Codebase Audit [2026] Read More »

Why Does My Angular HTTP Call Fire Twice? Causes and Fixes [2026]

1 Comment / Angular / Code-JS

Lesson 10.4 of the Angular tutorial — why HttpClient requests fire twice: cold Observables with multiple subscribers, effects that re-run, SSR without the HTTP transfer cache, retry loops and CORS preflights, plus a Network-panel routine to tell them apart.

Why Does My Angular HTTP Call Fire Twice? Causes and Fixes [2026] Read More »

Why Isn’t My Angular Component Updating? Zoneless and OnPush Debugging [2026]

Leave a Comment / Angular / Code-JS

Lesson 10.3 of the Angular tutorial — a step-by-step diagnosis for components that don’t update in zoneless, OnPush apps: same-reference mutations, signals not read in the template, untracked(), plain field writes in setTimeout or callbacks, service state, third-party libraries and Angular DevTools.

Why Isn’t My Angular Component Updating? Zoneless and OnPush Debugging [2026] Read More »

Debugging ExpressionChangedAfterItHasBeenChecked (NG0100) in Angular [2026]

1 Comment / Angular / Code-JS

Lesson 10.2 of the Angular tutorial — why the ExpressionChangedAfterItHasBeenChecked (NG0100) check exists, the five root causes behind it, fixes with signals, computed(), linkedSignal() and afterNextRender(), the workarounds to avoid, and how zoneless change detection changes the picture.

Debugging ExpressionChangedAfterItHasBeenChecked (NG0100) in Angular [2026] Read More »

Angular Runtime Errors Explained: NG0100 to NG0956 Catalog [2026]

1 Comment / Angular / Code-JS

Lesson 10.1 of the Angular tutorial — a reference catalog of the most common Angular runtime errors (NG0100, NG0200, NG0201, NG0203, NG0300, NG0302, NG0600, NG0950, NG0955, NG0956, the NG05xx hydration range and more), each with its cause, a minimal reproduction and the fix.

Angular Runtime Errors Explained: NG0100 to NG0956 Catalog [2026] Read More »

Angular SSR Caching and Edge Deployment: CDN, Cache-Control and TTFB [2026]

Leave a Comment / Angular / Code-JS

Lesson 9.7 of the Angular tutorial — caching rendered pages and assets with Cache-Control, keeping personal data out of shared caches, running on edge runtimes with AngularAppEngine, Node and serverless hosting with cold starts, and tactics for a lower time to first byte.

Angular SSR Caching and Edge Deployment: CDN, Cache-Control and TTFB [2026] Read More »

Angular TransferState and the HTTP Transfer Cache: Deep Dive [2026]

1 Comment / Angular / Code-JS

Lesson 9.6 of the Angular tutorial — how the HttpClient transfer cache avoids double fetches after SSR, its default rules, withHttpTransferCacheOptions and per-request transferCache, origin mapping, resource() with id, manual TransferState with makeStateKey, and keeping the payload small.

Angular TransferState and the HTTP Transfer Cache: Deep Dive [2026] Read More »

Angular Incremental Hydration with @defer Hydrate Triggers [2026]

Leave a Comment / Angular / Code-JS

Lesson 9.5 of the Angular tutorial — how incremental hydration keeps server-rendered @defer blocks dehydrated until a hydrate trigger fires, every hydrate trigger, placeholders and client-side navigation, nesting rules, event replay, and which sections are worth deferring.

Angular Incremental Hydration with @defer Hydrate Triggers [2026] Read More »

Angular Event Replay: Handling Clicks Before Hydration [2026]

Leave a Comment / Angular / Code-JS

Lesson 9.4 of the Angular tutorial — the gap between visible and interactive on SSR pages, how event replay captures and replays early clicks, how it is enabled by default in v22, what it does and does not replay, writing replay-tolerant handlers, and shrinking the gap.

Angular Event Replay: Handling Clicks Before Hydration [2026] Read More »