implement decimals setting

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@dgma/reverse-dutch-auction",
-  "version": "0.0.2",
+  "version": "0.0.3",
   "description": "Contracts for dutch reverse auction implementation",
   "files": [
     "src/*"

src/OpenRDA.sol

@@ -25,10 +25,6 @@ contract OpenRDA is RDA, RDAEvents {
 
     constructor() RDA() {}
 
-    function decimals() public pure override returns (uint8) {
-        return 8;
-    }
-
     function begin(
         bytes32 id,
         uint256 amountToCollect,

src/RDA.sol

@@ -21,10 +21,14 @@ abstract contract RDA is IRDA, OwnableUpgradeable, RDABase {
         _disableInitializers();
     }
 
-    function initialize(address owner, uint256 lotSize_, uint256 stepRate_, uint8 stepLength_)
-        external
-        initializer
-    {
+    function initialize(
+        address owner,
+        uint256 lotSize_,
+        uint256 stepRate_,
+        uint8 stepLength_,
+        uint8 decimals_
+    ) external initializer {
+        decimals = decimals_;
         __Ownable_init(owner);
         _setHouseParams(lotSize_, stepRate_, stepLength_);
     }

src/RDA.types.sol

@@ -33,13 +33,14 @@ struct Bid {
     uint256 toRedeem;
 }
 
-interface IRDAMeta {
-    function decimals() external pure returns (uint8);
-}
-
 interface IRDA {
-    function initialize(address owner, uint256 lotSize_, uint256 stepRate_, uint8 stepLength_)
-        external;
+    function initialize(
+        address owner,
+        uint256 lotSize_,
+        uint256 stepRate_,
+        uint8 stepLength_,
+        uint8 decimals_
+    ) external;
 
     function setHouseParams(uint256 lotSize_, uint256 stepRate_, uint8 stepLength_) external;
 

src/RDABase.sol

@@ -7,7 +7,6 @@ import {EnumerableSet} from "node_modules/@openzeppelin/contracts/utils/structs/
 import {RDAMathLib} from "./RDAMathLib.sol";
 
 import {
-    IRDAMeta,
     Auction,
     AuctionStats,
     Bid,
@@ -16,14 +15,15 @@ import {
     AuctionNotActive
 } from "./RDA.types.sol";
 
-abstract contract RDABase is IRDAMeta {
+abstract contract RDABase {
     using Math for uint256;
     using RDAMathLib for uint256;
     using EnumerableSet for EnumerableSet.Bytes32Set;
 
     uint256 public stepRate;
     uint256 public stepLength;
     uint256 public lotSize;
+    uint256 public decimals;
 
     mapping(bytes32 => Auction) internal auctions;
     EnumerableSet.Bytes32Set internal auctionsSet;
@@ -51,10 +51,6 @@ abstract contract RDABase is IRDAMeta {
         _;
     }
 
-    // pure getters
-
-    function decimals() public pure virtual returns (uint8);
-
     // internal API setters
 
     function _setHouseParams(uint256 lotSize_, uint256 stepRate_, uint8 stepLength_) internal {
@@ -95,8 +91,8 @@ abstract contract RDABase is IRDAMeta {
 
     // internal API Getters
 
-    function _denominator() internal pure returns (uint256) {
-        return 10 ** decimals();
+    function _denominator() internal view returns (uint256) {
+        return 10 ** decimals;
     }
 
     function _isAutcionActive(bytes32 id) internal view returns (bool) {

test/OpenRDA.t.sol

@@ -35,6 +35,8 @@ contract DutchAuctionHouseTest is RDAEvents, Test {
     uint256 private amountToCollect;
     uint256 private amountToDistribute;
 
+    uint8 private constant decimals = 8;
+
     bytes32 private id = keccak256(abi.encode(address(this)));
 
     address private notOwner = makeAddr("alice");
@@ -55,11 +57,11 @@ contract DutchAuctionHouseTest is RDAEvents, Test {
         redeemToken.mint(address(this), amountToDistribute);
 
         auctionHouse = OpenRDA(Clones.clone(address(new OpenRDA())));
-        auctionHouse.initialize(address(this), lotSize, stepRate, stepLength);
+        auctionHouse.initialize(address(this), lotSize, stepRate, stepLength, decimals);
     }
 
     function _maxFizzAuctionBlocks() private view returns (uint256) {
-        return Math.mulDiv(stepLength, 10 ** 8, stepRate);
+        return Math.mulDiv(stepLength, 10 ** decimals, stepRate);
     }
 
     function _prepareNotOwnerToBid(uint256 bidAmount) internal {