SolidJS & TanStack Query: Browser Stuck In Loading? Let's Fix It!

Hey guys! Ever run into a frustrating issue where your SolidJS browser tab just hangs in that annoying loading state? If you're using TanStack Query, especially with the enabled property, you might have been there. It's a real head-scratcher, but don't worry, we're going to dive deep into this bug, figure out what's going on, and hopefully, get your browser back to its snappy self. Let's get started, shall we?

The Bug: When enabled: false Causes a Hang

So, here's the deal. You're using TanStack Query with SolidJS, and you've cleverly set the enabled property to false initially. This is a common pattern, right? You want to hold off on fetching data until a certain condition is met – maybe a user clicks a button or something. The problem is, when this setup is used on the initial page load, it can sometimes make your browser tab get stuck in the dreaded loading state. The little spinner just keeps spinning, and nothing seems to happen. It's like the browser is in a perpetual state of waiting, even after the query should be enabled and the data is fetched. Bummer, right?

This isn't just a cosmetic issue; it's a usability killer. Nobody wants to stare at a loading spinner forever. It makes your app feel slow, unreliable, and generally unpleasant to use. This issue has been identified in the TanStack Query library, particularly when used in SolidJS applications. The problem primarily surfaces when the enabled property is set to false on initial page load, and the browser gets stuck in a loading state even after the query should have finished loading. The bug manifests in a way that prevents the browser from transitioning out of the loading state, leading to a poor user experience. This can be super annoying for users, especially if your app relies heavily on dynamic data loading. This is an issue that needs to be addressed to ensure a smooth and responsive experience for users interacting with applications built with SolidJS and TanStack Query. Addressing the issue will ensure that users are not left in a perpetual state of waiting when interacting with web applications built with SolidJS and TanStack Query. It directly impacts the perceived performance and responsiveness of the web application. A fix or workaround would contribute significantly to improving the user experience and the overall usability of applications. Let's delve deeper into this.

The Heart of the Problem

The root of the problem seems to be a conflict between how TanStack Query handles the enabled property in SolidJS and how the browser renders the page. When enabled is set to false initially, something goes awry during the initial render, causing the browser to get stuck. Even after you re-enable the query (and the data is fetched successfully), the browser doesn't update its state correctly, leaving that pesky loading indicator spinning. This behavior has been observed on Windows 11 using Chrome and Firefox browsers. It affects the perceived performance and responsiveness of web applications built with these technologies. The bug is triggered when enabled is initially set to false on the first page load. This issue primarily involves the interaction between the TanStack Query library, SolidJS, and the browser's rendering process. Let's explore more.

Reproducing the Issue: The Codesandbox Example

Fortunately, a reproducible example has been created, so we can see the problem in action. You can check it out on CodeSandbox (you can find the link in the provided context). This allows developers to easily replicate the issue and experiment with different solutions. The issue can be reproduced by navigating to the /demo route in the provided CodeSandbox example. This setup is crucial because it allows developers and other users to understand the problem. The ability to reproduce the issue is essential for both understanding the problem. The example clearly demonstrates the bug, making it easier to analyze and find solutions. It provides a controlled environment for testing potential fixes. The use of a minimal, reproducible example is a cornerstone of effective bug reporting. In the example, the /demo route showcases the problem. So, go ahead and try it out. Seeing the issue firsthand is always the best way to understand what's happening. The example serves as a useful tool for anyone encountering this specific issue in their SolidJS with TanStack Query projects.

Steps to Replicate

1. Open the Codesandbox Example: Head over to the provided link and load the project. This gives you a live, working environment to play with.
2. Navigate to the /demo Route: This specific route is where the bug manifests. It's set up to trigger the issue when the component loads. You should see the browser tab stuck in the loading state, the spinner never stopping. It's like the browser is just waiting and waiting.
3. Observe the Loading State: Notice how the loading state persists even when the data should have been fetched. It's a clear indication that something is not right with how the browser handles the query's state updates in conjunction with the enabled property. The persistent loading state is the key indicator of the bug. It affects the user experience by making the application seem unresponsive. This persistent state is what needs to be resolved.

Expected Behavior: What Should Happen?

So, what should happen when you set enabled to false initially? The browser tab should not get stuck in a loading state. That's the core of the problem. Here's what we expect:

• Initial Load: The query is disabled, and the browser doesn't show a loading indicator.
• Query Enabled: When the condition to enable the query is met, TanStack Query fetches the data.
• Data Fetched: The data is successfully fetched.
• Browser Updates: The browser should update its state, display the fetched data, and remove the loading spinner. Everything should be smooth and seamless. This seamless experience is what we are striving for!

Basically, the browser should transition gracefully between states, and the user shouldn't notice any hiccups. This is crucial for a positive user experience. The issue causes a breakdown in this transition, resulting in the loading state hanging indefinitely.

Bug Prevalence: How Often Does It Happen?

Unfortunately, this isn't a rare occurrence. The bug appears to happen every time the conditions are met. Every time you set enabled: false on initial page load in SolidJS with TanStack Query, you run the risk of hitting this issue. This high frequency makes it a critical bug to address. Users will consistently encounter this problem, leading to frustration and a poor user experience. Its consistent nature makes it a high-priority item for developers. The bug's consistent nature means it's a high-priority item for developers. This means anyone working on an app using this combo needs to be aware of the problem and look for solutions or workarounds.

Historical Context: Version Specifics

Interestingly, the bug's behavior varies depending on the version of TanStack Query you're using. This adds another layer of complexity. The bug’s behavior is influenced by the TanStack Query version in use. The presence or absence of the issue depends on the specific version of the library. Different versions of the library may exhibit different behaviors related to this issue. The details give developers more info to determine if a fix or a workaround is needed. It helps to pinpoint when the bug was introduced and when it was possibly resolved. This version-specific behavior underscores the need to be mindful of the library versions in use. Let's delve deeper:

• Versions Before 5.59.0: The issue wasn't present. Older versions of TanStack Query don't exhibit this behavior. If you're using an older version, you're likely safe, but you'll miss out on the latest features and bug fixes.
• Versions 5.59.0 to 5.85.5: The error experimental_prefetchInRender feature flag is not enabled appears to prevent the loading state hang. This error suggests that a specific feature is missing or disabled, which inadvertently prevents the bug from occurring. However, this is not an ideal solution, as the feature might be beneficial for other aspects of your application.
• Enabling experimental_prefetchInRender: When you enable this feature, the bug comes back. This indicates that the fix implemented between the versions was related to the presence or absence of this feature flag. It's a double-edged sword: the feature could be useful, but enabling it triggers the bug. If you enable this feature, the bug surfaces again. This is where it gets tricky: you may need to choose between using the feature or avoiding the bug.

Workarounds and Potential Solutions

While there's no single, perfect solution right now, there are a few workarounds and potential avenues to explore. Here are some options:

1. Avoid Initial enabled: false: One of the simplest workarounds is to avoid setting enabled to false on the initial page load if it's not strictly necessary. This might involve fetching data immediately or using a different mechanism to control the query's execution. This approach removes the primary trigger for the bug, avoiding the issue altogether. This can be the easiest solution if you can adjust your application logic. This may be the most straightforward approach if you can refactor your code to load data immediately.

2. Delay Query Execution: Instead of relying on enabled, you could delay the query's execution using a different approach, such as setTimeout or a reactive variable. This allows you to control the timing of the query more explicitly, potentially avoiding the initial rendering issues. You can control when the data fetch happens and avoid triggering the bug on the initial load. By timing the query, you can prevent the issue. This gives you more control over the timing of the data fetch, making it easier to avoid the bug.

3. Check for Updates and Potential Fixes: Keep an eye on the TanStack Query repository for updates and potential fixes. The developers are aware of the issue, and they may release a patch that addresses it directly. Check the repository for the latest updates. Stay on top of any potential solutions. Checking for updates is the most direct way to resolve the issue if a fix is provided by the library maintainers. Following this method is the most direct path to resolution.

4. Experiment with Feature Flags: If you're comfortable, you could experiment with enabling or disabling the experimental_prefetchInRender feature. However, keep in mind that this might come with its own set of side effects, and it's not a recommended long-term solution. Experimentation can help you understand the feature's influence. This method might provide a short-term fix but could have unforeseen consequences.

Conclusion: Navigating the Loading State Labyrinth

So, there you have it, guys. The SolidJS and TanStack Query loading state issue is a tricky one, but hopefully, you're now better equipped to understand it. Remember to test your code thoroughly, stay updated on the latest developments, and be patient while the community works towards a permanent fix. Good luck, and happy coding! I hope this helps you out. Remember to stay updated on the latest developments. Remember to test your code thoroughly.

This article provides a comprehensive overview of the SolidJS browser loading state issue in conjunction with TanStack Query and the enabled property. It breaks down the bug, its causes, and offers potential solutions and workarounds. By understanding the problem and exploring these strategies, developers can mitigate the impact of the bug, improve user experience, and create more responsive web applications.

This bug highlights the importance of thorough testing and staying up-to-date with library updates in web development. The goal is to provide a clear and actionable guide for developers facing this challenge.