changed ownerOf to _tokenOwners in _burn (#78)

* changed ownerOf to _tokenOwners in _burn

* changed ownerOf to _tokenOwners in _mint

* added internal ownerOf

* added doc, fixed require statements

* bumped version, returned _ownerOf() into _burn()

Author: VolodymyrZolotukhin

contracts/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@solarity/solidity-lib",
-  "version": "2.6.7",
+  "version": "2.6.8",
   "license": "MIT",
   "author": "Distributed Lab",
   "readme": "README.md",

contracts/tokens/SBT.sol

@@ -61,7 +61,7 @@ abstract contract SBT is ISBT, ERC165Upgradeable {
      * @return true if `tokenId_` exists, false otherwise
      */
     function tokenExists(uint256 tokenId_) public view virtual override returns (bool) {
-        return ownerOf(tokenId_) != address(0);
+        return _ownerOf(tokenId_) != address(0);
     }
 
     /**
@@ -101,7 +101,7 @@ abstract contract SBT is ISBT, ERC165Upgradeable {
      * @return address of an owner or `address(0)` if token does not exist
      */
     function ownerOf(uint256 tokenId_) public view virtual override returns (address) {
-        return _tokenOwners[tokenId_];
+        return _ownerOf(tokenId_);
     }
 
     /**
@@ -172,7 +172,7 @@ abstract contract SBT is ISBT, ERC165Upgradeable {
      * @param tokenId_ the token to burn
      */
     function _burn(uint256 tokenId_) internal virtual {
-        address owner_ = ownerOf(tokenId_);
+        address owner_ = _ownerOf(tokenId_);
         require(owner_ != address(0), "SBT: token doesn't exist");
 
         _beforeTokenAction(address(0), tokenId_);
@@ -204,6 +204,15 @@ abstract contract SBT is ISBT, ERC165Upgradeable {
         _baseURI = baseURI_;
     }
 
+    /**
+     * @notice The function to get the owner of a token
+     * @param tokenId_ the token to get the owner of
+     * @return address of an owner or `address(0)` if token does not exist
+     */
+    function _ownerOf(uint256 tokenId_) internal view virtual returns (address) {
+        return _tokenOwners[tokenId_];
+    }
+
     /**
      * @notice The hook that is called before the `mint` and `burn` actions occur
      * @param to_ the receiver address if `mint` and `address(0)` if burn

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@solarity/solidity-lib",
-  "version": "2.6.7",
+  "version": "2.6.8",
   "license": "MIT",
   "author": "Distributed Lab",
   "description": "Solidity Library by Distributed Lab",