Add unit tests for version-dispatcher and network-utils modules

[jolestar]

Problem

The version-dispatcher.ts and network-utils.ts modules lack comprehensive unit test coverage, which is critical for these core routing and utility functions.

Files to Test

1. src/network-utils.ts

Critical functions that need test coverage:

• getCanonicalNetwork() - Network canonicalization logic
• getNetworkDisplayName() - Network name resolution
• isCanonicalNetwork() - CAIP-2 format validation
• getCachedCanonicalNetwork() - Cached network lookup
• getSupportedCanonicalNetworks() - Returns all supported networks
• getSupportedHumanReadableNetworks() - Returns human-readable names
• validateNetwork() - Network validation with error handling
• determineX402Version() - Version detection from payload/body
• isVersionSupported() - Version support checking

2. src/version-dispatcher.ts

Critical class methods that need test coverage:

• VersionDispatcher.verify() - Version routing for verify operations
• VersionDispatcher.settle() - Version routing for settle operations
• VersionDispatcher.verifyV1() - V1 verification implementation
• VersionDispatcher.verifyV2() - V2 verification implementation
• VersionDispatcher.settleV1() - V1 settlement implementation
• VersionDispatcher.settleV2() - V2 settlement implementation
• VersionDispatcher.isV1SettlementRouterMode() - SettlementRouter mode detection

Test Scenarios to Cover

network-utils.ts

1. Network Canonicalization

   • Valid v1 names → v2 CAIP-2 identifiers
   • Valid v2 CAIP-2 → passthrough
   • Invalid networks → proper error messages
   • Case sensitivity handling
   • Cache functionality in getCachedCanonicalNetwork()

2. Version Detection

   • Version from paymentPayload.x402Version
   • Version from body.x402Version
   • Default to v1 when not specified
   • Invalid version numbers → error
   • Version support checking with/without FACILITATOR_ENABLE_V2 flag

3. Network Validation

   • Empty/undefined network strings
   • Non-string inputs
   • Valid networks returning canonical keys

version-dispatcher.ts

1. Version Routing

   • V1 requests route to v1 implementation
   • V2 requests route to v2 implementation (when enabled)
   • V2 requests rejected when disabled
   • Metrics recording for each version/mode

2. SettlementRouter Mode Detection

   • V1 with extra.settlementRouter → v1_settlementRouter mode
   • V1 without extra.settlementRouter → v1_standard mode
   • V2 always uses v2_router mode

3. Error Handling

   • Unsupported versions return appropriate errors
   • Invalid networks handled properly
   • V2 facilitator not initialized errors
   • Metrics recorded for errors

Acceptance Criteria

1. Test files created:
   • test/unit/network-utils.test.ts
   • test/unit/version-dispatcher.test.ts
2. All critical functions/methods have test coverage
3. Edge cases covered (invalid inputs, version mismatches, etc.)
4. Mock external dependencies (v2 facilitator, pool manager, etc.)
5. Coverage report shows >80% for both files
6. All tests pass consistently

Priority

High - These are core modules for v1/v2 routing and need reliable test coverage

Technical Notes

• Use viem mocks for EVM-related tests
• Mock x402 package functions
• Mock @x402x/* package functions
• Test both with FACILITATOR_ENABLE_V2=true and false
• Verify metrics recording using spies/mocks