Fix/koios evaluator response 610

[ruhil6789]

Summary

This PR fixes a bug in the Koios provider's evaluateTx method where the response from the Koios Ogmios endpoint was incorrectly handled. The Koios Ogmios endpoint returns the evaluation result as an object (matching the native Ogmios provider format), but the code was treating it as an array, causing evaluation failures or incorrect results.

Problem:

• The code checked data.result.length and used data.result.map() directly, assuming result was an array
• This caused issues when the Ogmios endpoint returned an object response

Solution:

• Changed the response handling to use Object.values(data.result) to convert the object to an array before mapping
• Removed the .length check since objects don't have a length property
• Added a comment explaining why Object.values() is used, matching the pattern from the Ogmios provider implementation

This fix ensures the Koios provider correctly implements IEvaluator and can be used with MeshTxBuilder for transaction evaluation.

Affect components

• @meshsdk/provider

Type of Change

• Bug fix (non-breaking change which fixes an issue)

Related Issues

• Closes Implement IEvaluator for Koios #610

Checklist

• My code is appropriately commented and includes relevant documentation, if necessary
• I have added tests to cover my changes, if necessary
• I have updated the documentation, if necessary
• All new and existing tests pass (i.e. npm run test)
• The build is pass (i.e. npm run build)

Additional Information

Changes Made:

File: packages/mesh-provider/src/koios.ts

1. Line 662: Changed from if (!data.result || !data.result.length) to if (!data.result)

   • Removed the .length check since result is an object, not an array

2. Line 666: Changed from return data.result.map(...) to return Object.values(data.result).map(...)

   • Converts the object response to an array before mapping, matching the Ogmios provider pattern

3. Added comment: Explains why Object.values() is used to handle the object response format

Technical Details:

The Koios API provides an Ogmios-compatible endpoint at /ogmios that returns evaluation results in the same format as the native Ogmios provider. The response structure is:

{
"result": {
"0": { "validator": {...}, "budget": {...} },
"1": { "validator": {...}, "budget": {...} }
}
}