refactor: remove source chain selectors getter and add additional todos

contracts/gas-snapshots/ccip.gas-snapshot

@@ -100,33 +100,33 @@ CommitStore_verify:test_TooManyLeaves_Revert() (gas: 36807)
 DefensiveExampleTest:test_HappyPath_Success() (gas: 207503)
 DefensiveExampleTest:test_Recovery() (gas: 431738)
 E2E:test_E2E_3MessagesSuccess_gas() (gas: 1036239)
-EVM2EVMMultiOffRamp__releaseOrMintTokens:test_PriceNotFoundForToken_Reverts() (gas: 132616)
-EVM2EVMMultiOffRamp__releaseOrMintTokens:test_TokenHandlingError_Reverts() (gas: 154975)
-EVM2EVMMultiOffRamp__releaseOrMintTokens:test__releaseOrMintTokens_PoolIsNotAContract_Reverts() (gas: 37960)
-EVM2EVMMultiOffRamp__releaseOrMintTokens:test__releaseOrMintTokens_PoolIsNotAPool_Reverts() (gas: 40130)
-EVM2EVMMultiOffRamp__releaseOrMintTokens:test_fuzz__releaseOrMintTokens_AnyRevertIsCaught_Success(uint256) (runs: 10024, μ: 30110, ~: 30806)
-EVM2EVMMultiOffRamp__releaseOrMintTokens:test_releaseOrMintTokens_Success() (gas: 184928)
-EVM2EVMMultiOffRamp_applySoureConfigUpdates:test_AddMultipleChains_Success() (gas: 313058)
-EVM2EVMMultiOffRamp_applySoureConfigUpdates:test_AddNewChain_Success() (gas: 143300)
-EVM2EVMMultiOffRamp_applySoureConfigUpdates:test_ApplyZeroUpdates_Success() (gas: 16973)
-EVM2EVMMultiOffRamp_applySoureConfigUpdates:test_MismatchingUpdateLenghts_Revert() (gas: 15949)
-EVM2EVMMultiOffRamp_applySoureConfigUpdates:test_ReplaceExistingChain_Success() (gas: 152561)
-EVM2EVMMultiOffRamp_applySoureConfigUpdates:test_ZeroOnRampAddress_Revert() (gas: 15639)
-EVM2EVMMultiOffRamp_constructor:test_Constructor_Success() (gas: 5561985)
-EVM2EVMMultiOffRamp_constructor:test_ZeroOnRampAddress_Revert() (gas: 144678)
-EVM2EVMMultiOffRamp_metadataHash:test_MetadataHashChangesOnOnRampAddress_Success() (gas: 11015)
-EVM2EVMMultiOffRamp_metadataHash:test_MetadataHashChangesOnSourceChain_Success() (gas: 11074)
-EVM2EVMMultiOffRamp_metadataHash:test_MetadataHash_Success() (gas: 9162)
-EVM2EVMMultiOffRamp_setDynamicConfig:test_NonOwner_Revert() (gas: 40366)
-EVM2EVMMultiOffRamp_setDynamicConfig:test_RouterZeroAddress_Revert() (gas: 38552)
-EVM2EVMMultiOffRamp_setDynamicConfig:test_SetDynamicConfig_Success() (gas: 142101)
+EVM2EVMMultiOffRamp__releaseOrMintTokens:test_PriceNotFoundForToken_Reverts() (gas: 132594)
+EVM2EVMMultiOffRamp__releaseOrMintTokens:test_TokenHandlingError_Reverts() (gas: 154953)
+EVM2EVMMultiOffRamp__releaseOrMintTokens:test__releaseOrMintTokens_PoolIsNotAContract_Reverts() (gas: 37938)
+EVM2EVMMultiOffRamp__releaseOrMintTokens:test__releaseOrMintTokens_PoolIsNotAPool_Reverts() (gas: 40108)
+EVM2EVMMultiOffRamp__releaseOrMintTokens:test_fuzz__releaseOrMintTokens_AnyRevertIsCaught_Success(uint256) (runs: 10025, μ: 30079, ~: 30784)
+EVM2EVMMultiOffRamp__releaseOrMintTokens:test_releaseOrMintTokens_Success() (gas: 184906)
+EVM2EVMMultiOffRamp_applySoureConfigUpdates:test_AddMultipleChains_Success() (gas: 261162)
+EVM2EVMMultiOffRamp_applySoureConfigUpdates:test_AddNewChain_Success() (gas: 94737)
+EVM2EVMMultiOffRamp_applySoureConfigUpdates:test_ApplyZeroUpdates_Success() (gas: 12362)
+EVM2EVMMultiOffRamp_applySoureConfigUpdates:test_ReplaceExistingChain_Success() (gas: 103269)
+EVM2EVMMultiOffRamp_applySoureConfigUpdates:test_ZeroOnRampAddress_Revert() (gas: 14511)
+EVM2EVMMultiOffRamp_constructor:test_Constructor_Success() (gas: 5413298)
+EVM2EVMMultiOffRamp_constructor:test_ZeroOnRampAddress_Revert() (gas: 143480)
+EVM2EVMMultiOffRamp_metadataHash:test_MetadataHashChangesOnOnRampAddress_Success() (gas: 10983)
+EVM2EVMMultiOffRamp_metadataHash:test_MetadataHashChangesOnSourceChain_Success() (gas: 11036)
+EVM2EVMMultiOffRamp_metadataHash:test_MetadataHash_Success() (gas: 9146)
+EVM2EVMMultiOffRamp_metadataHash:test_fuzz__MetadataHash_NoCollisions(uint64,uint64,uint64,address,address) (runs: 10001, μ: 4860854, ~: 4860854)
+EVM2EVMMultiOffRamp_setDynamicConfig:test_NonOwner_Revert() (gas: 40344)
+EVM2EVMMultiOffRamp_setDynamicConfig:test_RouterZeroAddress_Revert() (gas: 38530)
+EVM2EVMMultiOffRamp_setDynamicConfig:test_SetDynamicConfig_Success() (gas: 142128)
 EVM2EVMOffRamp__releaseOrMintTokens:test_OverValueWithARLOff_Success() (gas: 325154)
 EVM2EVMOffRamp__releaseOrMintTokens:test_PriceNotFoundForToken_Reverts() (gas: 125872)
 EVM2EVMOffRamp__releaseOrMintTokens:test_RateLimitErrors_Reverts() (gas: 647365)
 EVM2EVMOffRamp__releaseOrMintTokens:test_TokenHandlingError_Reverts() (gas: 148120)
 EVM2EVMOffRamp__releaseOrMintTokens:test__releaseOrMintTokens_PoolIsNotAContract_Reverts() (gas: 27226)
 EVM2EVMOffRamp__releaseOrMintTokens:test__releaseOrMintTokens_PoolIsNotAPool_Reverts() (gas: 29377)
-EVM2EVMOffRamp__releaseOrMintTokens:test_fuzz__releaseOrMintTokens_AnyRevertIsCaught_Success(uint256) (runs: 10024, μ: 23227, ~: 23925)
+EVM2EVMOffRamp__releaseOrMintTokens:test_fuzz__releaseOrMintTokens_AnyRevertIsCaught_Success(uint256) (runs: 10025, μ: 23227, ~: 23925)
 EVM2EVMOffRamp__releaseOrMintTokens:test_releaseOrMintTokens_Success() (gas: 177373)
 EVM2EVMOffRamp__report:test_Report_Success() (gas: 127403)
 EVM2EVMOffRamp__trialExecute:test_RateLimitError_Success() (gas: 200330)
@@ -368,10 +368,10 @@ PingPong_plumbing:test_Pausing_Success() (gas: 17765)
 PingPong_startPingPong:test_StartPingPong_Success() (gas: 170821)
 Pool__decodePoolReturnDataV1:test__decodePoolReturnDataV1_InvalidTag_Revert() (gas: 5148)
 Pool__generatePoolReturnDataV1:test__generatePoolReturnDataV1_Success() (gas: 8069)
-Pool__generatePoolReturnDataV1:test_fuzz__generatePoolReturnDataV1_Success(bytes,bytes) (runs: 256, μ: 9309, ~: 9164)
+Pool__generatePoolReturnDataV1:test_fuzz__generatePoolReturnDataV1_Success(bytes,bytes) (runs: 257, μ: 9307, ~: 9164)
 Pool__removeFirstFourBytes:test__removeFirstFourBytes_EmptyData_Success() (gas: 4696)
 Pool__removeFirstFourBytes:test__removeFirstFourBytes_MalformedPoolReturnData_Revert() (gas: 4387)
-Pool__removeFirstFourBytes:test_fuzz__removeFirstFourBytes_Success(bytes) (runs: 256, μ: 4894, ~: 4752)
+Pool__removeFirstFourBytes:test_fuzz__removeFirstFourBytes_Success(bytes) (runs: 257, μ: 4894, ~: 4752)
 PriceRegistry_applyFeeTokensUpdates:test_ApplyFeeTokensUpdates_Success() (gas: 79341)
 PriceRegistry_applyFeeTokensUpdates:test_OnlyCallableByOwner_Revert() (gas: 12434)
 PriceRegistry_applyPriceUpdatersUpdates:test_ApplyPriceUpdaterUpdates_Success() (gas: 82600)

contracts/src/v0.8/ccip/offRamp/EVM2EVMMultiOffRamp.sol

@@ -133,8 +133,9 @@ contract EVM2EVMMultiOffRamp is IAny2EVMOffRamp, AggregateRateLimiter, ITypeAndV
   /// @dev Tokens that should be included in Aggregate Rate Limiting
   /// An (address => address) map is used for backwards compatability of offchain code
   EnumerableMapAddresses.AddressToAddressMap internal s_rateLimitedTokensDestToSource;
+  // TODO: evaluate whether this should be pulled in (since this can be inferred from SourceChainSelectorAdded events instead)
   /// @notice all source chains available in s_sourceChainConfigs
-  uint64[] internal s_sourceChainSelectors;
+  // uint64[] internal s_sourceChainSelectors;
   /// @notice SourceConfig per chain
   /// (forms lane configurations from sourceChainSelector => StaticConfig.chainSelector)
   mapping(uint64 sourceChainSelector => SourceChainConfig) internal s_sourceChainConfigs;
@@ -153,7 +154,7 @@ contract EVM2EVMMultiOffRamp is IAny2EVMOffRamp, AggregateRateLimiter, ITypeAndV
   constructor(
     StaticConfig memory staticConfig,
     SourceChainConfigUpdateArgs[] memory sourceChainConfigs,
-    // TODO: convert to array (per-chain)
+    // TODO: convert to array to support per-chain config once multi-ARL is ready
     RateLimiter.Config memory rateLimiterConfig
   ) OCR2BaseNoChecks() AggregateRateLimiter(rateLimiterConfig) {
     if (staticConfig.commitStore == address(0)) revert ZeroAddressNotAllowed();
@@ -307,7 +308,8 @@ contract EVM2EVMMultiOffRamp is IAny2EVMOffRamp, AggregateRateLimiter, ITypeAndV
       uint64 prevNonce = s_senderNonce[message.sender];
       address prevOffRamp = s_sourceChainConfigs[message.sourceChainSelector].prevOffRamp;
       if (prevNonce == 0 && prevOffRamp != address(0)) {
-        // NOTE: assuming prevOffRamp is always a lane-specific off ramp
+        // TODO: assuming prevOffRamp is always a lane-specific off ramp
+        //       Update to additionally support IAny2EVMMultiOffRamp backwards compatibility
         prevNonce = IAny2EVMOffRamp(prevOffRamp).getSenderNonce(message.sender);
         if (prevNonce + 1 != message.nonce) {
           // the starting v2 onramp nonce, i.e. the 1st message nonce v2 offramp is expected to receive,
@@ -495,9 +497,9 @@ contract EVM2EVMMultiOffRamp is IAny2EVMOffRamp, AggregateRateLimiter, ITypeAndV
 
   /// @notice Returns all configured source chain selectors
   /// @return sourceChainSelectors source chain selectors
-  function getSourceChainSelectors() external view returns (uint64[] memory) {
-    return s_sourceChainSelectors;
-  }
+  // function getSourceChainSelectors() external view returns (uint64[] memory) {
+  //   return s_sourceChainSelectors;
+  // }
 
   /// @notice Updates source configs
   /// @param sourceChainConfigUpdates Source chain configs
@@ -518,7 +520,7 @@ contract EVM2EVMMultiOffRamp is IAny2EVMOffRamp, AggregateRateLimiter, ITypeAndV
 
       // OnRamp can never be zero - if it is, then the source chain has been added for the first time
       if (s_sourceChainConfigs[sourceChainSelector].onRamp == address(0)) {
-        s_sourceChainSelectors.push(sourceChainSelector);
+        // s_sourceChainSelectors.push(sourceChainSelector);
         emit SourceChainSelectorAdded(sourceChainSelector);
       }
 
@@ -613,6 +615,7 @@ contract EVM2EVMMultiOffRamp is IAny2EVMOffRamp, AggregateRateLimiter, ITypeAndV
   /// we bubble it up. If we encounter a non-rate limiting error we wrap it in a TokenHandlingError.
   function _releaseOrMintTokens(
     Client.EVMTokenAmount[] memory sourceTokenAmounts,
+    // TODO: revisit stack-depth after pulling in pool interface changes
     Any2EVMMessageRoute memory messageRoute,
     bytes[] memory encodedSourceTokenData,
     bytes[] memory offchainTokenData

contracts/src/v0.8/ccip/test/offRamp/EVM2EVMMultiOffRamp.t.sol

@@ -120,10 +120,10 @@ contract EVM2EVMMultiOffRamp_constructor is EVM2EVMMultiOffRampSetup {
     // Source config
     s_offRamp.applySourceConfigUpdates(sourceChainConfigs);
 
-    uint64[] memory resultSourceChainSelectors = s_offRamp.getSourceChainSelectors();
-    assertEq(resultSourceChainSelectors.length, 2);
-    assertEq(resultSourceChainSelectors[0], SOURCE_CHAIN_SELECTOR);
-    assertEq(resultSourceChainSelectors[1], SOURCE_CHAIN_SELECTOR + 1);
+    // uint64[] memory resultSourceChainSelectors = s_offRamp.getSourceChainSelectors();
+    // assertEq(resultSourceChainSelectors.length, 2);
+    // assertEq(resultSourceChainSelectors[0], SOURCE_CHAIN_SELECTOR);
+    // assertEq(resultSourceChainSelectors[1], SOURCE_CHAIN_SELECTOR + 1);
     _assertSourceChainConfigEquality(s_offRamp.getSourceChainConfig(SOURCE_CHAIN_SELECTOR), expectedSourceChainConfig1);
     _assertSourceChainConfigEquality(
       s_offRamp.getSourceChainConfig(SOURCE_CHAIN_SELECTOR + 1), expectedSourceChainConfig2
@@ -532,7 +532,7 @@ contract EVM2EVMMultiOffRamp_applySoureConfigUpdates is EVM2EVMMultiOffRampSetup
     Vm.Log[] memory logEntries = vm.getRecordedLogs();
     assertEq(logEntries.length, 0);
 
-    assertEq(s_offRamp.getSourceChainSelectors().length, 0);
+    // assertEq(s_offRamp.getSourceChainSelectors().length, 0);
   }
 
   function test_AddNewChain_Success() public {
@@ -562,9 +562,9 @@ contract EVM2EVMMultiOffRamp_applySoureConfigUpdates is EVM2EVMMultiOffRampSetup
 
     _assertSourceChainConfigEquality(s_offRamp.getSourceChainConfig(SOURCE_CHAIN_SELECTOR_1), expectedSourceChainConfig);
 
-    uint64[] memory resultSourceChainSelectors = s_offRamp.getSourceChainSelectors();
-    assertEq(resultSourceChainSelectors.length, 1);
-    assertEq(resultSourceChainSelectors[0], SOURCE_CHAIN_SELECTOR_1);
+    // uint64[] memory resultSourceChainSelectors = s_offRamp.getSourceChainSelectors();
+    // assertEq(resultSourceChainSelectors.length, 1);
+    // assertEq(resultSourceChainSelectors[0], SOURCE_CHAIN_SELECTOR_1);
   }
 
   function test_ReplaceExistingChain_Success() public {
@@ -599,9 +599,9 @@ contract EVM2EVMMultiOffRamp_applySoureConfigUpdates is EVM2EVMMultiOffRampSetup
 
     _assertSourceChainConfigEquality(s_offRamp.getSourceChainConfig(SOURCE_CHAIN_SELECTOR_1), expectedSourceChainConfig);
 
-    uint64[] memory resultSourceChainSelectors = s_offRamp.getSourceChainSelectors();
-    assertEq(resultSourceChainSelectors.length, 1);
-    assertEq(resultSourceChainSelectors[0], SOURCE_CHAIN_SELECTOR_1);
+    // uint64[] memory resultSourceChainSelectors = s_offRamp.getSourceChainSelectors();
+    // assertEq(resultSourceChainSelectors.length, 1);
+    // assertEq(resultSourceChainSelectors[0], SOURCE_CHAIN_SELECTOR_1);
   }
 
   function test_AddMultipleChains_Success() public {
@@ -645,15 +645,15 @@ contract EVM2EVMMultiOffRamp_applySoureConfigUpdates is EVM2EVMMultiOffRampSetup
 
     s_offRamp.applySourceConfigUpdates(sourceChainConfigs);
 
-    uint64[] memory resultSourceChainSelectors = s_offRamp.getSourceChainSelectors();
-    assertEq(resultSourceChainSelectors.length, 3);
+    // uint64[] memory resultSourceChainSelectors = s_offRamp.getSourceChainSelectors();
+    // assertEq(resultSourceChainSelectors.length, 3);
 
     for (uint256 i = 0; i < 3; ++i) {
       _assertSourceChainConfigEquality(
         s_offRamp.getSourceChainConfig(sourceChainConfigs[i].sourceChainSelector), expectedSourceChainConfigs[i]
       );
 
-      assertEq(resultSourceChainSelectors[i], sourceChainConfigs[i].sourceChainSelector);
+      // assertEq(resultSourceChainSelectors[i], sourceChainConfigs[i].sourceChainSelector);
     }
   }