Solving Error Code 10 in Mandos Tests with String Arrays in Endpoint Calls

Discover the solution to the frustrating error code 10 in Mandos tests when passing string arrays to endpoints. Learn how to use ManagedVec for proper serialization!
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Understanding the Problem: Error Code 10 in Mandos Tests

If you're diving into the world of blockchain development with MultiversX, you might encounter some issues, particularly when testing your smart contract endpoints. One common hurdle is error code 10, which signifies an execution failure when a string array is passed as an argument to an endpoint in Mandos tests.

In this guide, we will dissect the code that leads to this issue and propose a solution that can help you navigate this obstacle effectively.

The Code in Question

Here’s a snippet from the function that triggered the error:

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When testing this endpoint using Mandos, your call might look something like this:

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When executing the test, the result was disappointing:

[[See Video to Reveal this Text or Code Snippet]]

What’s Going Wrong?

The error arises during the serialization or deserialization process of the string array. The Mandos environment cannot handle arrays of type &[String] directly for this endpoint call, resulting in failure.

The Solution: Using ManagedVec

To resolve this issue, you need to utilize a special type from the Elrond SDK, known as ManagedVec, which facilitates proper serialization and deserialization of arrays. Here's how to adjust your function:

[[See Video to Reveal this Text or Code Snippet]]

Steps to Implement:

Change the Type: Replace &[String] with ManagedVec<ManagedBuffer>.

Test Your Endpoint: Once altered, run the endpoint again with your Mandos tests.

Why ManagedVec?

Serialization Compatibility: ManagedVec allows the Node to understand how to serialize and deserialize data correctly, preventing the error code 10 from occurring.

Performance: It optimizes the handling of dynamic arrays, making your smart contract more robust.

Conclusion

By addressing the serialization issue with ManagedVec, you can ensure your smart contract endpoints function properly without running into error code 10 in Mandos tests.

This solution not only saves you time but also reinforces your understanding of how data types interact within the Elrond blockchain environment. Happy coding, and may your projects thrive in the exciting realm of blockchain technology!