add receipt getter to erc20 vault

Author: thedavidmeister

src/concrete/vault/ERC20PriceOracleReceiptVault.sol

@@ -113,6 +113,14 @@ contract ERC20PriceOracleReceiptVault is ReceiptVault {
         return ICLONEABLE_V2_SUCCESS;
     }
 
+    /// Not strictly necessary as the receipt address is emitted during
+    /// initialization but this is a convenience getter for the receipt address.
+    /// It isn't in the `ReceiptVault` implementation because we need to keep the
+    /// base contract code size down.
+    function receipt() external view returns (address) {
+        return address(sReceipt);
+    }
+
     /// The ID is the current oracle price always, even if this ID has already
     /// been issued for some other receipt, it will simply result in multiple
     /// holders of receipts with amounts of the same ID.

test/src/concrete/vault/ERC20PriceOracleReceiptVault.construct.t.sol

@@ -35,6 +35,7 @@ contract ERC20PriceOracleReceiptVaultConstructionTest is ERC20PriceOracleReceipt
         address msgSender = address(0);
         IPriceOracleV2 priceOracle = IPriceOracleV2(payable(0));
         address assetAddress = address(0);
+        address receiptAddress = address(0);
         string memory name = "";
         string memory symbol = "";
         bool eventFound = false; // Flag to indicate whether the event log was found
@@ -53,6 +54,7 @@ contract ERC20PriceOracleReceiptVaultConstructionTest is ERC20PriceOracleReceipt
                 name = config.receiptVaultConfig.vaultConfig.name;
                 symbol = config.receiptVaultConfig.vaultConfig.symbol;
                 assetAddress = address(config.receiptVaultConfig.vaultConfig.asset);
+                receiptAddress = address(config.receiptVaultConfig.receipt);
                 eventFound = true; // Set the flag to true since event log was found
                 break;
             }
@@ -65,6 +67,7 @@ contract ERC20PriceOracleReceiptVaultConstructionTest is ERC20PriceOracleReceipt
         assert(address(vault) != address(0));
         assertEq(keccak256(bytes(vault.name())), keccak256(bytes(name)));
         assertEq(keccak256(bytes(vault.symbol())), keccak256(bytes(symbol)));
+        assertEq(receiptAddress, vault.receipt());
     }
 
     /// Test creating several different vaults