Angular Update Guide: Keeping Your Application Current

Anton Ioffe - December 9th 2023 - 10 minutes read

As the digital landscape evolves with unyielding momentum, staying adrift with the latest updates in Angular is crucial for the cutting-edge developer. This quintessential guide offers a navigational compass through the intricacies of updating your Angular applications, ensuring your project's resilience against the tide of change. We will decode the subtleties of version detection infused with CLI wisdom, master the art of version control to shield your codebase during transitions, unearth the tactical approaches to testing that fortify your updates, and conclude with a strategic foray into adopting novel features while accounting for groundbreaking shifts. Tap into a seamless Angular updating experience where the only constant is your application's unbroken continuity and enhancement.

Embracing the Angular Update Guide

As senior-level developers, we recognize the paramount importance of maintaining the currency of our Angular applications. The Angular Update Guide stands as an indispensable tool, meticulously crafted to ease the transition between different versions of Angular. Its comprehensive instructions cater to a variety of update scenarios, making it an essential first reference for any developer embarking on an update journey. By selecting our project's current Angular version and the target one we aspire to reach, we unlock a tailored set of procedures designed to minimize the friction commonly associated with version migration.

One profound advantage of adhering to the Angular Update Guide is its cognizance of the app's complexity. Whether we are scaling a basic prototype or an enterprise-grade application, the guide provides personalized directives that consider the intricacies and dependencies unique to our project. This adaptive approach not only ensures a smoother update experience but also underscores the guide's utility across the spectrum of Angular applications. It's imperative to meticulously follow the instructions laid out in the 'Before Updating', 'During the Update', and 'After the Update' sections, which systematically guide us through preparatory steps, the update process itself, and any post-update considerations.

The Angular team consistently infuses the update guide with insights drawn from evolving best practices and community feedback. This dynamic resource evolves in tandem with Angular itself, assimilating new tools and approaches, such as the ng update command introduced with Angular CLI 1.7. By leveraging such tools, we streamline the update process, reducing manual interventions and the scope for human error. This command alone serves as a beacon, guiding developers through package updates concisely and reliably, reflecting the broader intentions of the guide—to render the update process more deterministic and manageable.

It is central to note that updates to Angular not only introduce enhancements but also phase out deprecated features. The guide is an authoritative resource for identifying such deprecations and understanding the necessary remediations or replacements. Following the guide's advice helps maintain code hygiene and prepares our applications to harness the full potential of Angular's newer functionalities. Just as importantly, the guide encourages us to reevaluate and refactor our codebase, leading to improved performance and maintainability while ensuring our application’s alignment with contemporary development paradigms.

In conclusion, embracing the Angular Update Guide is not merely a recommendation—it's an industry-standard strategy that embodies forethought, efficiency, and responsibility in modern web development. By committing to its structured pathway, we safeguard our projects against the unintended consequences of ad-hoc updates and set them on a course of continuous improvement. The guide's role cannot be overstated; it is the compass by which we navigate the ever-shifting landscape of Angular development, preserving robustness and relevancy in our web applications.

Version Detection Nuances and CLI Considerations

Determining the precise version of Angular in use is paramount before embarking on an update, and the ng version command serves as the primary tool for this purpose. Running this command in your project directory will yield detailed version information not only for Angular core libraries but also for the Angular CLI and other related dependencies. One must scrutinize the output to discern the exact versions installed, as this dictates the update path and highlights any discrepancies that could impede the process.

Understanding the semantic versioning, denoted as MAJOR.MINOR.PATCH, is essential in the Angular ecosystem. A major version update (e.g., from 8.x.x to 9.x.x) potentially brings breaking changes, necessitating code modifications. On the flip side, minor and patch updates typically add new features and bug fixes, respectively, without disrupting existing functionality. Hence, developers must give thoughtful consideration to the type of update they wish to perform and the potential ripple effects on their codebase.

The [ng update]( command is intricately designed to ease the update process by automatically adjusting project dependencies. Yet, it's fundamental for developers to ensure that Angular CLI updates are executed in tandem with core library updates—this alignment avoids compatibility issues since CLI tools and core libraries are often tightly coupled, with features in one sometimes directly depending on the other.

Moreover, proceeding with an update requires a clear understanding of which versions are compatible with each other. Versions of @angular/core and @angular/cli must be in sync to exercise the full array of features and ensure the stability of the application. If these versions diverge, the development experience might suffer, and unexpected errors could arise during both development and runtime.

Lastly, while the ng update command effectively manages package dependencies leveraging npm or yarn, developers should be wary of third-party libraries. The Angular CLI may not fully understand custom update schematics provided by third parties, so an additional layer of caution is warranted when updating these packages. It is incumbent upon the developer to review any upgrade scripts and understand their impact on the project's code and structure to avert unintended consequences.

Strategic Use of Version Control During Updates

Before proceeding with an Angular update, initiate a new branch in your Git repository. This isolation ensures that all changes related to the update are contained in a single branch, distinct from your main codebase. When updating, you'll likely introduce significant changes to dependencies and potentially adjust large swathes of code to accommodate breaking changes. Having these changes in a separate branch allows you to toggle between the updated state and the original codebase without disrupting ongoing development in other parts of the project.

Utilize Git's commit capabilities judiciously throughout the Angular update process. Committing changes incrementally, with descriptive messages, highlights specific modifications and makes it easier to identify the step at which an issue may have been introduced. Moreover, should you need to roll back to a previous state, these granular commits provide a clear rollback path. Ensure that your commit messages articulate the nature of the changes therein, such as 'Updated @angular/core to 11.0.0' or 'Refactored XYZ components for Angular 11 compatibility'.

In the ambit of version control, leveraging Git tags pre-update is a strategic move. Tagging the pre-update state with semantic versioning, for instance, 'v10.0.0' before an upgrade to Angular 11, provides a clear snapshot of the project before any update-related modifications occur. This tag will serve as a quick reference to the stable version before the updates began. In the event of a need to compare the pre- and post-update state of the application or even revert to the pre-update version, this annotation is invaluable.

True to the principles of Agile and DevOps, incorporate automated testing into the Git branching strategy. After each substantive commit, automated unit and integration tests should run to validate the stable operation of the application at that point in the update chain. If a test fails, the culprit change is likely found in the last commit, facilitating a swift remediation. Continuously delivering working software, even in the midst of updates, is a hallmark of modern software development.

Finally, when confident in the update's success, the changes can be merged into the main branch. It's advisable to conduct this merge during a planned downtime or when user impact is minimal, as unforeseen issues can still occur despite rigorous testing. Use Git's merge tools to manage any conflicts and harness the power of collaboration by conducting code reviews with peers before the final merge. This due diligence ensures the collective ownership of the updated code and reinforces the stability of the final product.

By meticulously integrating these version control strategies, Angular project updates can be managed more effectively, significantly reducing risks associated with version migration. It puts in place a robust safety net and ensures that the stability of the project remains intact despite the changes made during the update process.

Testing Strategies Post-Update

Unit Testing with Jasmine

After updating your Angular application, it's critical to verify that each part performs as expected. Unit testing with Jasmine plays an essential role in this phase. Jasmine is a behavior-driven development framework for testing JavaScript code that works seamlessly with Angular. It allows developers to write clear and readable tests, which is critical for ensuring that individual functions and components work in isolation. However, a common pitfall is overmocking dependencies, which can mask issues that would surface in a real-world environment. Instead, strive to mock minimally and use actual implementations where practical, keeping tests relevant and robust.

Automated End-to-End Testing

To complement unit testing, end-to-end (E2E) testing validates the integrated functionality of the application as a whole. For Angular apps, tools like Protractor can simulate user interactions with the application and verify whether it behaves correctly. Automated E2E tests are potent because they test the workflow from the user's perspective. Nevertheless, they can be brittle if selectors used for querying DOM elements are volatile. To mitigate this, employ stable, unique selectors and avoid overly complex tests, splitting them into smaller, more manageable scenarios. This also improves test readability and maintainability.

Avoiding Test Redundancy

After updating an Angular app, reassess your test suite for redundancy. Duplicated effort in unit and E2E tests can lead to wasted resources and prolonged test runs. Aim for a balance – unit tests to cover individual functions and components, and E2E tests to confirm key user journeys. Additionally, consider implementing screenshot comparisons to detect visual regressions and validate user interface consistency post-update.

Testing Strategies Efficiency

Efficient testing strategies are essential to a streamlined development process. While writing tests, developers should be aware of the potential for false positives. Ensuring that tests genuinely verify the intended functionality requires attention to detail in assertions. Test cases should be accurate and effective, capturing the essence of what is meant to be tested without being overly general. This attention to detail ultimately leads to time savings, as it reduces the likelihood of having to revisit tests repeatedly.

Memory Leak Checks

Finally, updates can introduce memory leaks that go unnoticed during regular testing. Memory leaks can degrade performance over time and are often tricky to detect with unit or E2E tests. Incorporating performance profiling and memory leak detection into your testing process is essential. Using browser tools or Angular-specific services like ChangeDetectorRef, you can monitor the application's usage of system resources, ensuring that no new updates have compromised the application's sustainability. Addressing these issues promptly helps maintain application performance and end-user satisfaction.

Integrating new features from an Angular update while handling breakthrough changes requires a careful blend of innovation adoption and legacy maintenance. Developers must thread the needle between tapping into advancements and preserving existing functionality. One method to seamlessly introduce new features is through a layered approach, starting with core functionalities that have minimal dependency on uncertain aspects. Carefully increment this process, introducing more complex features once the foundational ones are tested and stable. This way, the application can benefit from performance optimizations inherent in newer Angular versions without risking immediate full-scale migrations.

The trick to managing deprecations effectively lies in anticipation and proactive refactoring. As you prepare for an update, audit your codebase for deprecated patterns and seek out their modern equivalents within the latest Angular release. Replace these outdated practices incrementally. The goal is to avoid a scenario in which a plethora of deprecations accumulate, leading to a daunting bulk migration. Instead, a continuous, iterative refactoring process keeps the code fresh and aligned with the evolutionary path of Angular.

Handling breakthrough changes, such as significant architectural shifts or entirely new APIs, demands a strategic rollout within the development team. Begin with a pilot project or an isolated module to gauge the impact of these changes. It’s imperative to document both the migration process and the encountered challenges. This knowledge becomes essential for educating the entire development team, ensuring best practices are maintained, and preventing the repetition of early mistakes.

To leverage performance improvements post-update without jeopardizing existing application compatibility, consider using feature flags or modular toggles. These allow for selective enablement of new features. They act as a switchboard to manage the risk associated with new feature integration, offering a safety net that can rollback changes to a stable state if issues arise. This approach promotes a cautious yet progressive transition that aligns with business requirements for uptime and reliability.

Despite the temptation to immediately refactor all code to utilize the latest Angular features, it’s critical to prioritize tasks based on ROI (Return on Investment). Evaluate the performance benefits against the complexity of the change. Simple replacements that yield considerable performance improvements should be addressed first. More complex, less impactful changes should be scheduled appropriately, balancing between the benefit and the need to focus on new feature development that delivers immediate value to the end-user. By doing so, developers ensure that the update enhances both the developer and user experience without becoming mired in endless refactoring.


In this article, senior-level developers are encouraged to embrace the Angular Update Guide, which provides comprehensive instructions for updating Angular applications. The article highlights the importance of version detection and CLI considerations, as well as the strategic use of version control and testing strategies post-update. It concludes by discussing how to navigate new features and breakthrough changes while maintaining code stability. Overall, the article emphasizes the need for careful planning and proactive maintenance when updating Angular applications. A challenging task for developers could be to refactor their codebase to replace deprecated patterns and optimize performance while minimizing the impact on existing functionality.

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