Qwik City: Fixing Public Files With Build.assetsDir

Facing issues with your Qwik City application's public files, especially when using build.assetsDir? You're not alone. This guide delves into a specific bug where setting build.assetsDir can prevent files like robots.txt and manifest.json from being served correctly. We'll explore the problem, its cause, and a potential solution, ensuring your Qwik City app functions flawlessly.

The Core Problem: Public Files Not Serving

When integrating a new Qwik City application with an existing Angular app on the same domain, managing static assets efficiently is crucial. The build.assetsDir option in Qwik allows developers to specify a directory for static assets, which can be incredibly useful for scenarios like whitelisting directories in a load balancer. However, setting build.assetsDir to a custom value, such as "q", can lead to unexpected behavior. Specifically, files placed in the public directory, such as robots.txt and manifest.json, may not be served as expected. This is a critical issue because search engines and browsers rely on these files for proper indexing and functionality.

For instance, the robots.txt file is essential for instructing search engine crawlers which parts of your site to index. If it's not served from the root, search engines may not be able to find it, which can impact your site's SEO. Similarly, manifest.json provides information about your web app, such as its name, icon, and the start URL, which is vital for progressive web app (PWA) features. When these files fail to load, the user experience and the overall functionality of your application can suffer.

In the context of the reported bug, the root cause lies in how Qwik City handles static file paths during the build process. The code appears to be prefixing the assetsDir to the file paths in the public directory, leading to incorrect file paths and causing the server to fail to locate these files. This prefixing can cause the server to look for files in the wrong location, preventing them from being served correctly.

Deep Dive: The Root Cause

The issue stems from how Qwik City's build process handles static files within the public directory. Specifically, the code that generates the list of static files appears to be incorrectly prefixing the assetsDir to the file paths. This results in the server looking for files in a location that doesn't exist. Let's break down the technical aspects and understand where this is happening.

Specifically, the isStaticFile check in the Qwik City routing logic determines whether a requested file is a static file that should be served directly. This check uses a list of static files detected during the build process. When build.assetsDir is set, the path to these files is incorrectly modified. For example, if you set build.assetsDir to "q", the path to robots.txt might be incorrectly generated as /q/q/robots.txt instead of /q/robots.txt. This is because the code unintentionally adds the assetsDir prefix twice.

The code responsible for this behavior is located within the qwik-city package, specifically in the vite/index.ts file. In this file, the path of the assets is being prefixed with the assetsDir. This addition, while intended to organize assets, inadvertently breaks the pathing for files located directly in the public directory.

Removing this prefixing effectively resolves the issue. The correct path to the static file is generated, and the server can find and serve the file correctly. However, manually modifying the core Qwik City files is generally not recommended as it can make updating your Qwik City installation more difficult and can introduce compatibility issues.

Reproduction and Steps to Fix

While the original report mentions that reproduction steps are not readily available, the issue is clear from the code and the described behavior. The core problem revolves around how the assetsDir is handled during the static file path generation. If you encounter this issue, here are the steps to identify and potentially fix it.

1. Inspect Your Build Configuration: First, review your qwik.config.ts (or equivalent) to ensure you have set build.assetsDir. This setting is key to triggering the bug. Check how the assetsDir is defined in your Qwik configuration file. Ensure it is set to a value that reflects your project's structure.
2. Examine the Build Output: After building your Qwik City application, inspect the output directory. Check if the static files in the public directory are correctly placed under your assetsDir. For instance, if your assetsDir is "q", verify that files like robots.txt and manifest.json are placed directly under the "q" directory in your build output.
3. Check the Server Logs: Examine your server logs to see if there are any 404 errors when requesting files like robots.txt or manifest.json. These errors usually indicate that the server cannot find the requested files. Server logs often contain detailed information about the request paths and the files the server is attempting to locate.
4. Implement a Temporary Workaround: As a temporary solution, you can manually move the affected files, such as manifest.json, into the correct directory after the build. However, this is not a sustainable solution and should only be used as a short-term fix while waiting for a permanent solution.

Solution and Considerations

The suggested solution involves removing the unnecessary prefixing of the assetsDir from the static file paths. However, directly modifying the core Qwik City files is generally discouraged because it can create maintenance issues and difficulties when updating your Qwik City installation. Ideally, a fix should be incorporated into the Qwik City framework itself. The fix involves modifying the code in the vite/index.ts file to ensure the path to the static files is correctly generated without the double prefixing of assetsDir.

Alternatively, consider adjusting your project structure to better accommodate the assetsDir setting. For example, you could move the contents of your public directory into a subdirectory within the public directory that matches your assetsDir. This approach might involve refactoring your application's setup to ensure all static assets are correctly placed within the specified asset directory during the build process.

Summary

This article has provided a detailed analysis of a bug in Qwik City that affects the serving of public files when build.assetsDir is configured. The core issue is related to incorrect path generation during the build process, which prevents files like robots.txt and manifest.json from being served correctly. The steps to reproduce the bug, the underlying cause, and possible solutions are discussed. The suggested temporary workarounds include inspecting build configuration, examining the build output, and manually moving the affected files. The best long-term solution involves modifying the Qwik City source code to prevent the double prefixing of assetsDir. Implementing these solutions will ensure your Qwik City application handles static files correctly and offers a seamless user experience.

In summary, by understanding the root cause, and the steps to reproduce the problem, you can take control of your Qwik City application and ensure that all public files serve correctly.

For more information, visit the Qwik documentation.