[Bug] Explorer does not render private view functions

[alnoki]

@banool @CapCap

Per @davidiw migrated from aptos-labs/aptos-core#8991

View functions can be declared as private when the output of the view function is generated by consuming a resource such that the write set is simply thrown away per aptos-labs/aptos-core#8539

Presently, the explorer does not render view functions that are declared private, even though these should be publicly accessible outside of the VM.

Example

Private view function source code: https://github.com/econia-labs/econia/blob/c79e58eeb7129029d9336edd6205c8aaf73e3866/src/move/econia/sources/market.move#L935-L980

CLI view output:

econia_testnet_addr=0x40b119411c6a975fca28f1ba5800a8a418bba1e16a3f13b1de92f731e023d135
aptos move view \
    --function-id $econia_testnet_addr::market::index_orders \
    --args String:1
{
  "Result": [
    {
      "asks": [],
      "bids": [
        {
          "custodian_id": "0",
          "order_access_key": "1",
          "price": "900",
          "size": "1",
          "user": "0x40b119411c6a975fca28f1ba5800a8a418bba1e16a3f13b1de92f731e023d135"
        },
        {
          "custodian_id": "0",
          "order_access_key": "2",
          "price": "899",
          "size": "1",
          "user": "0x40b119411c6a975fca28f1ba5800a8a418bba1e16a3f13b1de92f731e023d135"
        },
        {
          "custodian_id": "0",
          "order_access_key": "3",
          "price": "898",
          "size": "1",
          "user": "0x40b119411c6a975fca28f1ba5800a8a418bba1e16a3f13b1de92f731e023d135"
        }
      ]
    }
  ]
}

Explorer link with missing view function:

https://explorer.aptoslabs.com/account/0x40b119411c6a975fca28f1ba5800a8a418bba1e16a3f13b1de92f731e023d135/modules/view/assets?network=testnet

Explorer render with market::index_orders() missing:

[0xbe1]

@alnoki it is because private view function are not included in the generated abi file, and the explorer replies on generated abi to list all entry/view functions.

@gregnazario does it make sense to add private view function to generated abi?

[gregnazario]

Actually the generated ABI file and the ABI from the module API differ. The module API includes private entry functions as well.

[0xbe1]

Actually the generated ABI file and the ABI from the module API differ. The module API includes private entry functions as well.

@gregnazario Not sure i follow, but i check alex's example module https://api.testnet.staging.aptoslabs.com/v1/accounts/0x40b119411c6a975fca28f1ba5800a8a418bba1e16a3f13b1de92f731e023d135/modules?limit=1000 but i cannot find function index_orders in the response abi field - do i miss anything?

[gregnazario]

Private entry functions will show, but private view functions do not

[gregnazario]

@cursoragent can you reconstruct private view functions that are in the source code, but aren't showing in the UI? It should be able to parse out, variable names, return type, type arguments, and the function name. It MUST have #[view] above it

It should show up as something like:

#[view]
fun name<T1: type1, T2: type2>(arg1: u64, arg2: u8): bool {
    // ...
}

[cursor]

Perfect! Everything passes. Now let me create a comprehensive summary of the changes:

Summary

I've successfully implemented functionality to reconstruct and display private view functions in the Aptos Explorer. The solution parses Move source code to extract private view functions that have the #[view] attribute but are not included in the API's ABI response.

Changes Made

1. Added parsing utilities (app/utils/utils.ts):

   • extractPrivateViewFunctions(): Main parser that extracts private view functions from Move source code
   • parseGenericTypeParams(): Parses generic type parameters with constraints (e.g., T: copy + drop)
   • parseParameters(): Extracts function parameter types
   • parseReturnType(): Handles single and tuple return types
   • New PrivateViewFunction interface to represent parsed functions

2. Updated Contract component (app/pages/Account/Tabs/ModulesTab/Contract.tsx):

   • Modified the moduleAndFnsGroup useMemo hook to include both:
     • Exposed functions from the ABI (as before)
     • Parsed private view functions from source code (new)
   • Private view functions are only parsed for the "View Functions" tab
   • Merged private functions with public ones in a unified list

3. Added comprehensive tests (app/utils/utils.test.ts):

   • 10 new test cases covering:
     • Simple private view functions
     • Functions with parameters
     • Generic type parameters with constraints
     • Tuple return types
     • Multiple functions in one module
     • Complex nested types
     • Edge cases (empty source, no matches)

4. Created issue documentation (.agents/issues/2026-01-09-private-view-functions-support.md)

Technical Details

The parser uses a regex pattern to match private view functions:

/#\[view\]\s+fun\s+([a-zA-Z_][a-zA-Z0-9_]*)\s*(<[^>]*>)?\s*\(([^)]*)\)(?:\s*:\s*([^{]+))?/g

This pattern:

• Matches functions with #[view] attribute followed by fun keyword (not public fun)
• Extracts: function name, generic parameters, parameters, and return type
• Handles complex types like vector<Order>, 0x1::option::Option<address>, etc.
• Supports tuple return types: (u64, address, bool)

Testing

All 68 tests pass, including:

• ✅ 10 new tests for private view function parsing
• ✅ All existing tests remain passing
• ✅ Linting and formatting checks pass

How It Works

When viewing a module's "View Functions" tab:

1. The explorer fetches module data from the API (includes public functions only)
2. It also fetches the package metadata which contains source code
3. Source code is decompressed and parsed for private view functions
4. Private view functions are converted to the same format as public functions
5. Both are merged and displayed in the UI with full interactivity

This allows users to discover and execute private view functions that were previously hidden from the explorer interface.

---

 

_{Learn more about Cursor Agents}