Require solidity version, add NFT contract versions

solidity/contracts/LiquidInfrastructureNFT.sol

@@ -1,5 +1,5 @@
-// SPDX-License-Identifier: MIT
-pragma solidity ^0.8.12;
+//SPDX-License-Identifier: Apache-2.0
+pragma solidity 0.8.12; // Force solidity compliance
 
 import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
 import "@openzeppelin/contracts/token/ERC721/ERC721.sol";
@@ -38,6 +38,12 @@ contract LiquidInfrastructureNFT is ERC721, OwnableApprovableERC721 {
     address[] private thresholdErc20s;
     uint256[] private thresholdAmounts;
 
+    /**
+     * @notice This is the current version of the contract. Every update to the contract will introduce a new
+     * version, regardless of anticipated compatibility.
+     */
+    uint256 public constant Version = 1;
+
     /**
      * @notice This NFT holds only 1 token in it, which is the Account token. Its Id is `1`.
      * This Id is used for access control via the onlyOwner/onlyOwnerOrApproved modifiers.

solidity/contracts/OwnableApprovableERC721.sol

@@ -1,4 +1,5 @@
-pragma solidity ^0.8.10;
+//SPDX-License-Identifier: Apache-2.0
+pragma solidity 0.8.12; // Force solidity compliance
 
 import "@openzeppelin/contracts/utils/Context.sol";
 import "@openzeppelin/contracts/token/ERC721/ERC721.sol";

solidity/contracts/TestERC20A.sol

@@ -1,5 +1,5 @@
 //SPDX-License-Identifier: Apache-2.0
-pragma solidity ^0.8.10;
+pragma solidity 0.8.12; // Force solidity compliance
 import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
 
 // One of three testing coins

solidity/contracts/TestERC20B.sol

@@ -1,5 +1,5 @@
 //SPDX-License-Identifier: Apache-2.0
-pragma solidity ^0.8.10;
+pragma solidity 0.8.12; // Force solidity compliance
 import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
 
 // One of three testing coins

solidity/contracts/TestERC20C.sol

@@ -1,5 +1,5 @@
 //SPDX-License-Identifier: Apache-2.0
-pragma solidity ^0.8.10;
+pragma solidity 0.8.12; // Force solidity compliance
 import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
 
 // One of three testing coins

solidity/contracts/TestERC721A.sol

@@ -1,5 +1,5 @@
 //SPDX-License-Identifier: Apache-2.0
-pragma solidity ^0.8.10;
+pragma solidity 0.8.12; // Force solidity compliance
 import "@openzeppelin/contracts/token/ERC721/ERC721.sol";
 
 // Generate NFTs with token ids 1-10 and 190-195

x/microtx/keeper/liquid_account.go

@@ -28,6 +28,8 @@ var DefaultGasLimit uint64 = 30000000
 // type will cause execution failure
 var AccountId *big.Int = big.NewInt(1)
 
+var CurrentNFTVersion *big.Int = big.NewInt(1)
+
 // DoLiquify will deploy a LiquidInfrastructureNFT smart contract for the given account.
 // The token will then be transferred to the given account and live under its control.
 // Transfer to another owner requires interacting with the EVM
@@ -58,6 +60,14 @@ func (k Keeper) deployLiquidInfrastructureNFTContract(ctx sdk.Context, account s
 		return common.Address{}, sdkerrors.Wrap(err, "liquid infrastructure account contract deployment failed")
 	}
 
+	version, err := k.queryLiquidInfrastructureContractVersion(ctx, contract)
+	if err != nil {
+		return common.Address{}, sdkerrors.Wrap(err, "could not query NFT version")
+	}
+	if version.Cmp(CurrentNFTVersion) != 0 {
+		return common.Address{}, sdkerrors.Wrapf(err, "expected contract with version %v, got %v", CurrentNFTVersion, version)
+	}
+
 	_, err = k.transferLiquidInfrastructureNFTFromModuleToAddress(ctx, contract, account)
 	if err != nil {
 		return common.Address{}, sdkerrors.Wrapf(err, "could not transfer nft from %v to %v", types.ModuleEVMAddress.Hex(), SDKToEVMAddress(account).Hex())
@@ -103,6 +113,17 @@ func (k Keeper) queryLiquidInfrastructureOwner(ctx sdk.Context, nftAddress commo
 	return &owner, nil
 }
 
+// queryLiquidInfrastructureContractVersion fetches the `Version()` of the LiquidInfrastructureNFT deployed at `nftAddress`
+func (k Keeper) queryLiquidInfrastructureContractVersion(ctx sdk.Context, nftAddress common.Address) (*big.Int, error) {
+	// ABI: uint256 public constant Version
+	res, err := k.QueryEVM(ctx, "Version", types.LiquidInfrastructureNFT, types.ModuleEVMAddress, &nftAddress)
+	if err != nil {
+		return nil, sdkerrors.Wrap(err, "unable to call Versionw with no args")
+	}
+	version := big.NewInt(0).SetBytes(res.Ret)
+	return version, nil
+}
+
 // queryLiquidInfrastructureThresholds is used by the module to control liquid infrastructure account balances, it calls the
 // LiquidInfrastructureNFT getThresholds() function and formats the output into a useable type
 func (k Keeper) queryLiquidInfrastructureThresholds(ctx sdk.Context, nftAddress common.Address) ([]types.LiquidAccountThreshold, error) {

x/microtx/types/errors.go

@@ -10,4 +10,5 @@ var (
 	ErrNoLiquidAccount    = sdkerrors.Register(ModuleName, 3, "account is not a liquid infrastructure account")
 	ErrInvalidThresholds  = sdkerrors.Register(ModuleName, 4, "invalid liquid infrastructure account thresholds")
 	ErrInvalidMicrotx     = sdkerrors.Register(ModuleName, 5, "invalid microtx")
+	ErrInvalidContract    = sdkerrors.Register(ModuleName, 6, "invalid contract")
 )