Angular Code Review:
Checklist, Best Practices, and Tools

Angular is hard to write. The reason for this is that silent failures and scattered components make even small features unpredictable. A single UI (user interface) line can trigger a dozen chain reactions that are hard to spot. In short, that’s why developers need every advantage they can get. To ease the burden, we’ve made an Angular code review checklist of mistakes and configurations to check.

Our software development company has worked with large Angular codebases across multiple industries. At DevCom, we’ve reviewed thousands of Angular pull requests across clients in FinTech, logistics, retail, and more, so we know where even senior teams tend to slip up.

In this article, you’ll find a detailed checklist of best practices to streamline reviews, avoid common mistakes, and discover tools that help keep your Angular app fast, manageable, and secure.

Angular rewards coding discipline, consistency, and properly typed components. Because Angular applications often scale across releases, even minor deviations compound into serious problems. 

Below are the most critical reasons why companies should establish and follow an Angular review checklist:

• Keeping pace with Angular’s release cycles. Angular ships major updates roughly every six months along with regular minor and patch releases. Each version may deprecate APIs, tweak rendering behavior, or enforce stricter type safety. However, ongoing code review ensures compatibility and avoids blocked pipelines.
• Controlling performance regressions. Many performance issues in Angular (like eagerly loaded modules that bloat the initial bundle or inefficient structural directives) don’t trigger runtime errors. Without disciplined code review, they can quietly degrade app performance and slip into production.
• Strengthening cybersecurity posture. Angular can only prevent the most common front-end threats. Code reviews help catch front-end vulnerabilities introduced by risky developer shortcuts, unsafe third-party packages, or a misunderstanding of Angular’s built-in security boundaries.
• Reducing technical debt. Teams can introduce shortcuts that collide with routing logic, duplicate existing functionality, or force shared services to grow beyond their original scope. These are easy to spot during reviews, but if ignored, they can accumulate into technical debt.
• Preventing repetition through shared practices. Without shared conventions, teams can use inconsistent approaches and rework the same problems. Code reviews teach contributors to enforce coding styles and practices consistently, keeping the codebase understandable to developers who join the project later.
• Preserving architectural boundaries. Rushed commits leak business logic into user interface (UI) components, misuse shared services, or introduce tight coupling between features. Code review gives teams the time to catch the “cracks” before the architecture starts to bend under poor coding choices.

Code reviews work best when the submission is already clean, consistent, and easy to understand. The tips below help developers simplify the review as much as possible:

• Run ng lint with @angular-eslint and autofix enabled (–fix). This resolves obvious problems automatically and enforces Angular-specific rules like naming conventions, lifecycle hook order, and template accessibility.
• Execute unit tests to validate the coverage baseline. Ideally, over 80% of functions, branches, and lines should be exercised during test runs.
• Use the ng build –configuration=production command. This triggers Angular’s Ahead-of-Time (AOT) compiler—a stricter build process that can surface errors missed during development.
• Generate a Lighthouse CI report. Run a Lighthouse audit against the updated UI elements to see how pull requests impact user-facing areas, such as routers, pages, and components.
• Rebase the branch onto the latest main or trunk branch. It will replay local changes on top of the current repository state, producing a commit history with meaningful changes only (without noise from outdated core or merge commits).

Well-prepared code makes it easier for developers to spot both critical flaws and subtle issues.

No matter which version you’re using, either Angular 20 or Angular 8, this code review checklist should help you identify and address hidden problems. You can use it as a line-by-line reference for how the components and settings are supposed to work.

Module and Folder Structure

• Each business feature resides in its own folder under /modules or /features, with its own routing files, abstractions, state logic, and tests.
• Folders reflect domain boundaries, with modules (such as sales, inventory, or marketing) managing their own routes, state, and components.
• Deep imports have configured path aliases, as opposed to fragile relative paths (e.g., @shared/components/button instead of ../../../../shared/components/button).
• Shared and core modules are separated: SharedModule holds stateless and reusable pieces like directives and pipes; CoreModule contains app-wide services such as authentication and error handling.
• Lazy-loaded modules use dynamic imports, properly configured with title, data, and canActivate.

Component Architecture and Responsibilities

• Presentational components only handle layout and appearance, meaning components like Button, ProfileCard, or OrderList shouldn’t have business logic or service injections.
• OnPush Change Detection by default in all stateless or presentational components. Bindings should rely on immutable inputs or observables (not global state).
• Templates avoid complex expressions, like chained pipes, ternary operators, or embedded loops.
• Lifecycle hooks only appear when needed, without unused hooks or duplication of constructor logic.
• Components encapsulate styles using Angular’s view encapsulation (default) or scoped CSS with class-based naming (like BEM).
• Classes are semantic and not tied to global themes or hacks, especially in projects using utility-first frameworks like Tailwind.

Template and Style Hygiene

• No more than three chained structural directives in a block to avoid brittle DOM trees. Break up excessive chains.
• Observables piped through async are accessed safely using the ? operator or as syntax (*ngIf=”user$ | async as user”) to prevent null errors.
• Interactive elements include aria-labels, descriptive text, or associated <label> elements for accessibility
•  without relying solely on color.
• Component styles are isolated, and global resets, mixins, or overrides don’t leak into components.
• Every iterable uses a trackBy function returning a unique key to avoid excessive re-rendering.

Reactive Extensions for JavaScript (RxJS)

• Operators are imported from rxjs/operators and used with the pipe() function, not legacy patch-style imports (like import ‘rxjs/add/operator/map’).
• Flattening operators match the business logic: switchMap cancels the previous request, mergeMap runs all inner streams concurrently, exhaustMap ignores new triggers, concatMap preserves order, etc.
• Every subscribe() call in a component includes a teardown mechanism, like takeUntil(this.destroy$) or @UntilDestroy(), to prevent memory leaks.
• Observable values are emitted immutably, not mutated.
• Streams are combined without nested subscribe() calls using operators like combineLatest, withLatestFrom, forkJoin, or switchMap.

Service Layer and Dependency Injection

• UI logic is separated from shared services. Flag any services that manipulate the DOM, use ElementRef, browser alert(), component @Input, or local state.
• Feature-specific services are provided in lazy-loaded modules, such as CartService or SettingsFacade.
• Global services are declared with providedIn: “root” for things like authentication or telemetry.
• External libraries are integrated via InjectionToken or abstract classes to avoid tight coupling.
• HTTP interceptors perform stateless tasks, like adding auth headers or retrying failed requests.

Error Handling and Logging

• HttpClient requests include a catchError block to avoid silent failures and stuck UI components.
• All error and event logging routes through a dedicated LoggingService with metadata and consistent usage (this.loggingService.error(…)).
• GlobalErrorHandler should be extended to capture uncaught exceptions and show friendly error pages.
• Returned Promise values must be awaited, wrapped in try/catch blocks, or returned as error tuples (e.g., return [null, error]) for the caller to handle.

Angular encourages consistency through its CLI-generated scaffolding, decorators, and module structure. To avoid errors and keep the codebase explainable, enforce these standards:

• Follow lowercase kebab-case for file names.
• Avoid redundant suffixes like .component.ts or .service.ts when the folder already defines the type.
• Don’t use overly verbose names—they bloat paths and autocomplete suggestions.
• Use unique selectors within the app or across micro-frontends to avoid collisions.
• Prefix selectors with a short project- or team-specific namespace, like app-, dm-, or ui- (defined in angular.json).
• Limit each component to a single UI responsibility.
• Place async logic and state handling inside the component class or delegate to services.
• Keep ternary operators, chained conditions, and API calls out of templates.
• Enable strict TypeScript mode (strict: true in tsconfig.json). Exceptions must be rare and documented.
• Keep Angular templates declarative and readable—ideally under 80 characters.
• Split complex conditional logic into ng-template blocks or child components.
• Avoid any and object types—they disable type safety and risk runtime errors.
• Use literal types, interfaces, or generics to express intent.
• Enable TypeScript compiler options like noImplicitAny, strictNullChecks, and noUncheckedIndexedAccess.
• Use intent-revealing names for functions and variables to speed up code review.
• Group function or constructor inputs into objects when there are more than two scalar arguments.
• Use const by default. Use let only when reassignment is needed.
• Use barrel files for public APIs to avoid bloated import paths.
• Apply the “Rule of Three”: extract shared logic after the third repetition.

Teams that enforce these coding standards get safer refactors, faster onboarding, and more predictable development velocity.

Excellent code is the result of repeated reviews. The practices below can strengthen the review process and reduce the chance of missed architectural, performance, or security issues.

• Structure review as focused sessions. Rather than reviewing a large pull request all at once, divide it by concern (module structure, template logic, testing changes, etc.). Keep each session under 30 or 60 minutes to avoid attention drift.
• Prioritize high-risk areas. Locate and examine changes that have broad effects (such as exposed APIs, route definitions, dependency injection providers, etc.) before proceeding to component-level logic and UI.
• Rotate reviewers to distribute knowledge. If the same developer always reviews service-layer code or route configuration, their assumptions start to define the architecture. To avoid this, rotate review responsibilities across contributors. 
• Leave clear inline comments. Instead of writing something like “unclear logic” at the bottom of the pull request, reviewers should use inline comments to point to specific lines and suggest exact improvements.
• Surface and tag technical debt. Clearly tag temporary hacks, edge-case workarounds, and rushed architectural decisions. To make these issues stand out, use a consistent prefix such as // TECH_DEBT: followed by a summary.
• Request commit-linked responses. When a reviewer suggests a change, the author should respond with a reference to the specific commit that implements it. This makes it easier to understand why the change was made in follow-up reviews.
• Enforce project-specific ESLint rules. Linting in Angular projects enforces style and behavior rules, which saves time on small fixes and prevents unnecessary debates between reviewers. 
• Track recurring review failures. Schedule team syncs, seminars, or pairing sessions to walk through the problematic areas of the review process.

Even with a solid code review checklist, a few problems can still slip through if developers are unaware of them.

Many Angular problems stem from preventable mistakes that reviewers miss when they focus only on whether the code “works.” These issues are much easier to catch with a disciplined, methodical team that knows the tooling.

Avoiding these mistakes makes testing more meaningful, reduces regression risk, and enforces structural discipline. So, all we have left to cover is the tooling.

Reliable tools can catch issues that might slip past manual review. The ones below automate repetitive checks and highlight smaller problems, freeing your team to focus on architecture, quality, and performance at a higher level.

Linting and Formatting

Linting and formatting tools enforce stylistic consistency in TypeScript and template code. They “clean” the surface of a codebase before the reviewer can work in it.

• angular-eslint extends the standard ESLint engine to support Angular-specific code patterns.
• Prettier is a code formatter that enforces consistent spacing, indentation, bracket placement, and line length.
• eslint-plugin-prettier bridges ESLint and Prettier, which reports formatting violations as linting errors.

Static Analysis

Analysis tools scan projects for deep quality problems, like high-complexity functions, untested code paths, unreachable branches, and duplicate logic. Basically, issues that pile up the technical debt.

• SonarQube is a static analysis platform that supports Angular, TypeScript, and HTML templates and that analyzes numerous categories of code quality issues.
• eslint-plugin-sonarjs enhances the linting process by adding static code analysis, primarily focusing on logic flaws and readability issues.
• DeepSource is a cloud-based DevSecOps platform that integrates static analysis and automatic fixes into the pull request workflow.

Testing and Coverage

These tools help validate unit tests (for components, services, and pipes), integration tests (for combined logic), and end-to-end (E2E) tests during the review.

• Jasmine framework defines how you write and organize your tests (using functions like describe, it, expect, and beforeEach) and provides a syntax for your cases.
• Jest test runner integrates with CI/CD pipelines with capabilities to test in parallel, snapshot testing, and mocking tools (to isolate service calls and simulate async behavior).
• Karma is a verified, even if deprecated, runner that tests your Angular application inside the browser in a real-life execution environment.
• Playwright and Cypress can simulate clicks, user inputs, route transitions, and API calls in a browser.

Bundle and Performance Insight

Angular apps can feel fast in development but load slowly in production if you skip optimization. The following tools can expose these issues, helping reviewers catch poor module loading, excessive bundle sizes, and performance regressions in pull requests.

• Webpack Bundle Analyzer visualizes the contents of your final JavaScript bundle, helping find oversized dependencies, duplicates, or improperly shared code.
• source-map-explorer analyzes a minified bundle using source maps. It shows which source files contribute to the bundle size, how files depend on each other, and how shared modules are split across chunks.
• Lighthouse CI is a Google audit tool for performance, accessibility, and SEO tests in web apps.

Collaboration Review

Collaborative platforms offer built-in review features that can help teams manage pull requests, trigger automated checks, and guide reviewers toward meaningful feedback.

• GitHub pull requests create a discussion thread around code changes, display diffs with inline comments, support merge rules via branch protection settings, and preserve the full decision history.
• Bitbucket Pull Requests integrates with the Atlassian ecosystem (JIRA and Confluence).
• Azure DevOps Repos (Git) is geared toward enterprise teams using the full Microsoft ecosystem.

Not all Angular applications need the entire toolchain. Smaller apps may only require @angular-eslint, Prettier, Jest, and Lighthouse CI. But enterprise monorepos often benefit from deeper testing with SonarCloud, Playwright, and Cypress to catch technical debt, enforce quality gates, and run E2E smoke tests.

Angular development demands structure, and so does Angular code review. By following a proven checklist, developers can spot issues before they spiral into downtime, security gaps, or costly rewrites. 

But internal reviews aren’t always enough, since familiarity with the codebase can blind teams to patterns they’ve grown used to. That’s where a fresh set of eyes helps. DevCom’s code review services give your source code an outside audit so you can optimize your Angular apps and ship cleaner code. Contact us today.