Fixing NEAR Wallet 'Cannot Read Properties Of Undefined' Error
Hey guys! Running into a frustrating issue when trying to connect your NEAR wallet using Rsbuild with React and @near-wallet-selector
? You're not alone! This pesky error, "Cannot read properties of undefined (reading 'signer')", can halt your development progress, but don't worry, we'll dive into the potential causes and how to troubleshoot them like pros. This article provides an in-depth look at resolving the Cannot read properties of undefined (reading 'signer')
error encountered when integrating NEAR Wallet Selector with React applications built using Rsbuild. We'll explore the common causes behind this issue and provide step-by-step solutions to help you successfully connect to your wallet. Whether you're using Here Wallet, Meteor Wallet, Sender, Nightly, or any other NEAR-compatible wallet, this guide will help you diagnose and fix the problem.
Understanding the Error
Before we jump into solutions, let's break down what this error message actually means. The error "Cannot read properties of undefined (reading 'signer')" essentially indicates that you're trying to access the signer
property of a variable that is currently undefined
. In the context of @near-wallet-selector
, this usually points to a problem with how the wallet selector is initialized, how the wallet is being connected, or how the signer is being accessed after a successful connection. Understanding this is crucial, because, without the signer
, your application will not be able to execute transactions on the NEAR blockchain. This is because the signer
is the object responsible for signing transactions, acting as the user's permission and authority to interact with the network. Think of it as the key to your NEAR account. Without it, you can't unlock the door to blockchain interactions. Debugging this requires a systematic approach, starting from checking your initialization code to verifying your wallet connection flow. By understanding what the error means, you can be more precise in your troubleshooting, leading to a quicker resolution.
Common Causes and Troubleshooting Steps
So, what are the usual suspects behind this error? Let's explore the common causes and how to tackle them:
1. Incorrect Initialization of Wallet Selector
The most frequent culprit is an issue with the initialization of @near-wallet-selector
. If the selector isn't set up correctly, the signer
object might not be available when you try to use it. Always make sure you follow the official documentation and examples for initializing the wallet selector. It may seem simple, but a small error in the configuration can lead to this frustrating error. A crucial part of the initialization process is configuring the network, contract ID, and available wallets correctly. If these settings are off, the selector might not be able to establish a proper connection, leading to the undefined signer
. Double-checking these configurations can often reveal the source of the problem. Another key aspect is ensuring the necessary plugins and modules are correctly imported and included in the initialization process. For instance, if you're using a specific wallet like Ledger, you need to ensure the Ledger plugin is correctly configured. Similarly, for features like transaction signing, the appropriate modules need to be included. A missing or misconfigured plugin can directly result in the signer
being unavailable. Furthermore, make sure that the version of the packages used are compatible with each other and the NEAR platform. Incompatibilities between versions of @near-wallet-selector
core, react hooks, and wallet implementations can also cause unexpected behavior. Checking the version compatibility and updating the packages to their latest compatible versions can resolve such issues.
How to troubleshoot:
- Double-check your initialization code: Compare it against the official
@near-wallet-selector
documentation and examples. - Verify your network configuration: Ensure you're connecting to the correct NEAR network (testnet or mainnet).
- Inspect your wallet configuration: Make sure the wallets you're trying to use are properly configured within the selector.
2. Asynchronous Issues with Wallet Connection
Wallet connections are asynchronous operations. This means that the connection process takes time, and the signer
object might not be immediately available after you initiate the connection. If you try to access the signer
before the connection is fully established, you'll likely encounter this error. This can be tricky to debug because the asynchronous nature of the operations can hide the root cause. It's like trying to use a key before the lock has fully engaged – it simply won't work. To handle this, you need to ensure that your code waits for the connection to complete before attempting to use the signer
. This is often achieved using async/await
or promises. Without proper handling of these asynchronous operations, you risk running into this error consistently. Moreover, the order in which you call these asynchronous functions matters. Calling the connection method before the wallet selector is fully initialized will lead to errors. Always ensure that the wallet selector is fully set up and ready before attempting to connect to a wallet.
How to troubleshoot:
- Use
async/await
: Make sure you're usingasync/await
when connecting to the wallet and accessing thesigner
. - Check your promise handling: If you're using promises, ensure you're handling the resolution and rejection properly.
- Implement loading states: Show a loading indicator while the wallet is connecting to prevent users from interacting with the app before the
signer
is available.
3. Component Unmounting Before Connection Completes
In React applications, components can unmount (disappear from the screen) if their conditions are no longer met. If your component unmounts while the wallet connection is in progress, the connection might not complete properly, and the signer
might not be available. This is particularly common in single-page applications where navigation can quickly change the rendered components. When a component unmounts mid-connection, the underlying asynchronous processes might get interrupted, leading to incomplete initialization or connection. This is like trying to assemble a puzzle while someone keeps taking pieces away – it's hard to finish. To avoid this, you need to make sure that the connection process is handled in a way that persists across component unmounts or that the component remains mounted until the connection is complete. This can involve moving the connection logic to a higher-level component or using state management solutions to persist the wallet connection status.
How to troubleshoot:
- Ensure your component stays mounted: Check if your component is unmounting prematurely.
- Move connection logic: Consider moving the wallet connection logic to a higher-level component that persists across route changes.
- Use state management: Use a state management library (like Redux or Zustand) to persist the wallet connection state.
4. Rsbuild-Specific Configuration Issues
Since you're using Rsbuild, there might be specific configuration issues related to the build process that are interfering with the @near-wallet-selector
. Rsbuild, like any build tool, has its own set of configurations and optimizations that can sometimes cause unexpected behavior with external libraries. For example, certain optimizations might strip out necessary code or mangle variables in a way that breaks the wallet selector's functionality. This can manifest as the undefined signer
error because essential parts of the library are not being correctly processed. Therefore, it's important to ensure that Rsbuild is configured in a way that is compatible with @near-wallet-selector
. This may involve adjusting the build settings to prevent unwanted optimizations or ensuring that the necessary modules are correctly included in the build.
How to troubleshoot:
- Check Rsbuild configuration: Review your
rsbuild.config.ts
(or similar) file for any potential conflicts. - Experiment with different build settings: Try disabling certain optimizations or plugins to see if they're causing the issue.
- Consult Rsbuild documentation: Look for any specific guidance on using external libraries or troubleshooting build issues.
5. Wallet-Specific Issues
Although you mentioned the error occurs with multiple wallets, it's still worth considering that a particular wallet might have its own quirks or issues. While the error is consistent across wallets, it doesn't completely rule out the possibility of individual wallet-related problems. Some wallets might have specific requirements or configurations that need to be met for proper integration with @near-wallet-selector
. These requirements can sometimes be overlooked, leading to errors like the undefined signer
. For instance, a wallet might require a specific version of the library or might have compatibility issues with certain browsers or environments. Therefore, it's advisable to check the documentation for each wallet you're using to ensure that you've met all the necessary requirements and configurations. Additionally, testing with different wallets can help narrow down whether the issue is specific to a particular wallet or a more general problem with your setup.
How to troubleshoot:
- Check wallet documentation: Review the documentation for each wallet you're using for any specific requirements or known issues.
- Test with different wallets: Try connecting with a variety of wallets to see if the issue is isolated to a particular one.
- Update wallet extensions: Ensure your wallet extensions are up to date.
Practical Steps to Resolve the Error
Okay, enough theory! Let's get our hands dirty with some practical steps to fix this error:
- Review Initialization Code: Go back to your code where you initialize
@near-wallet-selector
. Double-check that you've included all the necessary configurations, such as the network ID, contract ID, and wallet list. - Implement Asynchronous Handling: Use
async/await
when connecting to the wallet and retrieving thesigner
. This ensures that your code waits for the connection to complete before trying to use thesigner
. - Check Component Lifecycle: Ensure your component isn't unmounting before the wallet connection is established. You might need to move the connection logic to a parent component or use a state management solution.
- Inspect Rsbuild Configuration: Look at your
rsbuild.config.ts
file and see if there are any settings that might be interfering with@near-wallet-selector
. Try disabling optimizations or plugins to see if that resolves the issue. - Test with Different Wallets: Try connecting with different wallets to see if the issue is specific to one wallet or a general problem with your setup.
- Check for Package Version Conflicts: Ensure that the versions of
@near-wallet-selector
core, react hooks, and wallet implementations are compatible. Update packages to their latest compatible versions if necessary.
Example: Implementing Async/Await
Here's a simple example of how to use async/await
when connecting to a wallet:
import { useWalletSelector } from "@near-wallet-selector/react";
import { useEffect, useState } from "react";
function MyComponent() {
const { selector, modal, accountId, accounts, wallet } = useWalletSelector();
const [signer, setSigner] = useState(null);
useEffect(() => {
async function fetchSigner() {
if (wallet) {
try {
// Await the wallet connection
const newSigner = await wallet.getSigner();
setSigner(newSigner);
} catch (error) {
console.error("Error getting signer:", error);
}
}
}
fetchSigner();
}, [wallet]);
// ... your component logic using the signer
return (
<div>
{/* ... */}
</div>
);
}
export default MyComponent;
In this example, we use async/await
to ensure that we wait for the wallet.getSigner()
method to resolve before trying to use the signer
. This prevents the error from occurring if the connection is still in progress.
Key Takeaways
- The "Cannot read properties of undefined (reading 'signer')" error in
@near-wallet-selector
usually indicates an issue with wallet initialization, asynchronous operations, or component lifecycle. - Thoroughly review your initialization code, use
async/await
for wallet connections, and ensure your component doesn't unmount prematurely. - Rsbuild-specific configurations and wallet-specific issues can also contribute to this error.
- By systematically troubleshooting these potential causes, you can resolve the error and get your NEAR wallet connected successfully.
Conclusion
The "Cannot read properties of undefined (reading 'signer')" error can be a real head-scratcher, but by understanding the common causes and following these troubleshooting steps, you can conquer it! Remember to double-check your initialization, handle asynchronous operations with care, and consider Rsbuild-specific configurations. With a bit of patience and methodical debugging, you'll have your NEAR wallet connected and your app running smoothly in no time. Happy coding, and feel free to share your experiences and solutions in the comments below!