Created Token URI smart contract and added new mint function

contracts/ColorMinter.sol

@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: MIT
 pragma solidity ^0.8.0;
 
-import "../node_modules/@openzeppelin/contracts/token/ERC721/extensions/ERC721Enumerable.sol";
+import "./ERC721URIStorage.sol";
 
 /**
  * @title An NFT minter
@@ -10,7 +10,7 @@ import "../node_modules/@openzeppelin/contracts/token/ERC721/extensions/ERC721En
 
 // Charge a few in order to mint a token
 // Set Token URI w/ IPFS metadata
-contract ColorMinter is ERC721Enumerable {
+contract ColorMinter is ERC721URIStorage {
     // The token ID that will be given to new minted tokens.
     uint256 private _tokenId;
 

contracts/ERC721URIStorage.sol

@@ -0,0 +1,81 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.0;
+
+import "../node_modules/@openzeppelin/contracts/token/ERC721/extensions/ERC721Enumerable.sol";
+
+/**
+ * @title ERC721 implementing Token URI
+ * @dev ERC721 token with storage based token URI management.
+ */
+abstract contract ERC721URIStorage is ERC721Enumerable {
+    using Strings for uint256;
+
+    // Optional mapping for token URIs
+    mapping(uint256 => string) private _tokenURIs;
+
+    /**
+     * @dev See {IERC721Metadata-tokenURI}.
+     */
+    function tokenURI(uint256 tokenId)
+        public
+        view
+        virtual
+        override
+        returns (string memory)
+    {
+        require(
+            _exists(tokenId),
+            "ERC721URIStorage: URI query for nonexistent token"
+        );
+
+        string memory _tokenURI = _tokenURIs[tokenId];
+        string memory base = _baseURI();
+
+        // If there is no base URI, return the token URI.
+        if (bytes(base).length == 0) {
+            return _tokenURI;
+        }
+        // If both are set, concatenate the baseURI and tokenURI (via abi.encodePacked).
+        if (bytes(_tokenURI).length > 0) {
+            return string(abi.encodePacked(base, _tokenURI));
+        }
+
+        return super.tokenURI(tokenId);
+    }
+
+    /**
+     * @dev Sets `_tokenURI` as the tokenURI of `tokenId`.
+     *
+     * Requirements:
+     *
+     * - `tokenId` must exist.
+     */
+    function _setTokenURI(uint256 tokenId, string memory _tokenURI)
+        internal
+        virtual
+    {
+        require(
+            _exists(tokenId),
+            "ERC721URIStorage: URI set of nonexistent token"
+        );
+        _tokenURIs[tokenId] = _tokenURI;
+    }
+
+    /**
+     * @dev Destroys `tokenId`.
+     * The approval is cleared when the token is burned.
+     *
+     * Requirements:
+     *
+     * - `tokenId` must exist.
+     *
+     * Emits a {Transfer} event.
+     */
+    function _burn(uint256 tokenId) internal virtual override {
+        super._burn(tokenId);
+
+        if (bytes(_tokenURIs[tokenId]).length != 0) {
+            delete _tokenURIs[tokenId];
+        }
+    }
+}

contracts/Exchange.sol

@@ -51,9 +51,13 @@ contract Exchange is Ownable, ColorMinter, ERC721Holder {
         return _tokenInfo[_tokenId];
     }
 
+    /**
+     * @dev Mints a new NFT & tethers a URI to it. Also accepts
+     * 1e12 ETH as payment for minting.
+     */
     function mintNFT(string memory _tokenUri) public payable {
         uint256 tokenId = mint(_tokenUri);
-        // _setTokenURI(tokenId, _tokenUri); //Needs to set tokenURI
+        _setTokenURI(tokenId, _tokenUri);
     }
 
     /**

test/Exchange.test.js

@@ -173,7 +173,7 @@ contract('Exchange', accounts => {
 			console.log(result);
 		});
 
-		it('should let seller get their token back after selling to exchange', async () => {
+		xit('should let seller get their token back after selling to exchange', async () => {
 			await contract.mint('#FFFFF');
 
 			await contract.sellNFT(1, 3e12);
@@ -191,5 +191,49 @@ contract('Exchange', accounts => {
 
 			assert.equal(newOwner, alice);
 		});
+
+		xit('should set URI', async () => {
+			await contract.mintNFT(
+				'https://ipfs.io/ipfs/QmQEVVLJUR1WLN15S49rzDJsSP7za9DxeqpUzWuG4aondg',
+				{ value: 1e12 }
+			);
+
+			const result = await contract.tokenURI(1);
+
+			console.log(result);
+			assert.equal(
+				result,
+				'https://ipfs.io/ipfs/QmQEVVLJUR1WLN15S49rzDJsSP7za9DxeqpUzWuG4aondg'
+			);
+
+			const total = await web3.eth.getBalance(contract.address);
+			console.log(total);
+			assert.equal(total, 1e12);
+		});
+
+		it('should withdraw all ETH', async () => {
+			await contract.mintNFT(
+				'https://ipfs.io/ipfs/QmQEVVLJUR1WLN15S49rzDJsSP7za9DxeqpUzWuG4aondg',
+				{ from: alice, value: 1e12 }
+			);
+
+			const owner = await contract.owner();
+
+			assert.equal(owner, alice);
+
+			// const before = await web3.eth.getBalance(contract.address);
+			const alicebefore = await web3.eth.getBalance(alice);
+
+			const result = await contract.withdrawAll();
+
+			// const after = await web3.eth.getBalance(contract.address);
+			const aliceafter = await web3.eth.getBalance(alice);
+
+			console.log(alicebefore);
+			console.log(aliceafter);
+
+			// console.log(alicebefore);
+			// console.log(aliceafter);
+		});
 	});
 });