Audit updates

src/ABT20.sol

@@ -6,7 +6,7 @@ import {ERC20Permit} from "@openzeppelin/contracts/token/ERC20/extensions/ERC20P
 import {Multicall} from "@openzeppelin/contracts/utils/Multicall.sol";
 
 abstract contract ABT20 is ERC20, ERC20Permit, Multicall {
-    uint8 private _decimals;
+    uint8 private immutable _decimals;
 
     constructor(string memory name, string memory symbol, uint8 decimals_) ERC20(name, symbol) ERC20Permit(name) {
         _decimals = decimals_;

src/ABT20Burn.sol

@@ -16,6 +16,8 @@ contract ABT20Burn is ABT20, AccessControlEnumerable {
         address defaultAdmin,
         address burner
     ) ABT20(name, symbol, decimals_) {
+        require(defaultAdmin != address(0), "DefaultAdmin address cannot be zero");
+        require(burner != address(0), "Burner address cannot be zero");
         _mint(initialHolder, initialSupply);
         _grantRole(DEFAULT_ADMIN_ROLE, defaultAdmin);
         _grantRole(BURNER_ROLE, burner);

src/ABT20BurnPause.sol

@@ -19,6 +19,9 @@ contract ABT20BurnPause is ABT20, AccessControlEnumerable, Pausable {
         address burner,
         address pauser
     ) ABT20(name, symbol, decimals_) {
+        require(defaultAdmin != address(0), "DefaultAdmin address cannot be zero");
+        require(burner != address(0), "Burner address cannot be zero");
+        require(pauser != address(0), "Pauser address cannot be zero");
         _mint(initialHolder, initialSupply);
         _grantRole(DEFAULT_ADMIN_ROLE, defaultAdmin);
         _grantRole(BURNER_ROLE, burner);

src/ABT20Mint.sol

@@ -16,6 +16,8 @@ contract ABT20Mint is ABT20, AccessControlEnumerable {
         address defaultAdmin,
         address minter
     ) ABT20(name, symbol, decimals_) {
+        require(defaultAdmin != address(0), "DefaultAdmin address cannot be zero");
+        require(minter != address(0), "Minter address cannot be zero");
         _mint(initialHolder, initialSupply);
         _grantRole(DEFAULT_ADMIN_ROLE, defaultAdmin);
         _grantRole(MINTER_ROLE, minter);

src/ABT20MintBurn.sol

@@ -18,6 +18,9 @@ contract ABT20MintBurn is ABT20, AccessControlEnumerable {
         address minter,
         address burner
     ) ABT20(name, symbol, decimals_) {
+        require(defaultAdmin != address(0), "DefaultAdmin address cannot be zero");
+        require(minter != address(0), "Minter address cannot be zero");
+        require(burner != address(0), "Burner address cannot be zero");
         _mint(initialHolder, initialSupply);
         _grantRole(DEFAULT_ADMIN_ROLE, defaultAdmin);
         _grantRole(MINTER_ROLE, minter);

src/ABT20MintBurnCap.sol

@@ -21,6 +21,9 @@ contract ABT20MintBurnCap is ABT20, ERC20Capped, AccessControlEnumerable {
         address burner,
         uint256 cap
     ) ABT20(name, symbol, decimals_) ERC20Capped(cap) {
+        require(defaultAdmin != address(0), "DefaultAdmin address cannot be zero");
+        require(minter != address(0), "Minter address cannot be zero");
+        require(burner != address(0), "Burner address cannot be zero");
         _mint(initialHolder, initialSupply);
         _grantRole(DEFAULT_ADMIN_ROLE, defaultAdmin);
         _grantRole(MINTER_ROLE, minter);

src/ABT20MintBurnCapPause.sol

@@ -24,6 +24,10 @@ contract ABT20MintBurnCapPause is ABT20, ERC20Capped, AccessControlEnumerable, P
         address pauser,
         uint256 cap
     ) ABT20(name, symbol, decimals_) ERC20Capped(cap) {
+        require(defaultAdmin != address(0), "DefaultAdmin address cannot be zero");
+        require(minter != address(0), "Minter address cannot be zero");
+        require(burner != address(0), "Burner address cannot be zero");
+        require(pauser != address(0), "Pauser address cannot be zero");
         _mint(initialHolder, initialSupply);
         _grantRole(DEFAULT_ADMIN_ROLE, defaultAdmin);
         _grantRole(MINTER_ROLE, minter);

src/ABT20MintBurnPause.sol

@@ -21,6 +21,10 @@ contract ABT20MintBurnPause is ABT20, AccessControlEnumerable, Pausable {
         address burner,
         address pauser
     ) ABT20(name, symbol, decimals_) {
+        require(defaultAdmin != address(0), "DefaultAdmin address cannot be zero");
+        require(minter != address(0), "Minter address cannot be zero");
+        require(burner != address(0), "Burner address cannot be zero");
+        require(pauser != address(0), "Pauser address cannot be zero");
         _mint(initialHolder, initialSupply);
         _grantRole(DEFAULT_ADMIN_ROLE, defaultAdmin);
         _grantRole(MINTER_ROLE, minter);

src/ABT20MintCap.sol

@@ -19,6 +19,8 @@ contract ABT20MintCap is ABT20, ERC20Capped, AccessControlEnumerable {
         address minter,
         uint256 cap
     ) ABT20(name, symbol, decimals_) ERC20Capped(cap) {
+        require(defaultAdmin != address(0), "DefaultAdmin address cannot be zero");
+        require(minter != address(0), "Minter address cannot be zero");
         _mint(initialHolder, initialSupply);
         _grantRole(DEFAULT_ADMIN_ROLE, defaultAdmin);
         _grantRole(MINTER_ROLE, minter);

src/ABT20MintCapPause.sol

@@ -22,6 +22,9 @@ contract ABT20MintCapPause is ABT20, ERC20Capped, AccessControlEnumerable, Pausa
         address pauser,
         uint256 cap
     ) ABT20(name, symbol, decimals_) ERC20Capped(cap) {
+        require(defaultAdmin != address(0), "DefaultAdmin address cannot be zero");
+        require(minter != address(0), "Minter address cannot be zero");
+        require(pauser != address(0), "Pauser address cannot be zero");
         _mint(initialHolder, initialSupply);
         _grantRole(DEFAULT_ADMIN_ROLE, defaultAdmin);
         _grantRole(MINTER_ROLE, minter);

src/ABT20MintPause.sol

@@ -19,6 +19,9 @@ contract ABT20MintPause is ABT20, AccessControlEnumerable, Pausable {
         address minter,
         address pauser
     ) ABT20(name, symbol, decimals_) {
+        require(defaultAdmin != address(0), "DefaultAdmin address cannot be zero");
+        require(minter != address(0), "Minter address cannot be zero");
+        require(pauser != address(0), "Pauser address cannot be zero");
         _mint(initialHolder, initialSupply);
         _grantRole(DEFAULT_ADMIN_ROLE, defaultAdmin);
         _grantRole(MINTER_ROLE, minter);

src/ABT20Pause.sol

@@ -17,6 +17,8 @@ contract ABT20Pause is ABT20, Pausable, AccessControlEnumerable {
         address defaultAdmin,
         address pauser
     ) ABT20(name, symbol, decimals_) {
+        require(defaultAdmin != address(0), "DefaultAdmin address cannot be zero");
+        require(pauser != address(0), "Pauser address cannot be zero");
         _mint(initialHolder, initialSupply);
         _grantRole(DEFAULT_ADMIN_ROLE, defaultAdmin);
         _grantRole(PAUSER_ROLE, pauser);