3. Stake Tokens

src/contracts/TokenFarm.sol

@@ -8,8 +8,35 @@ contract TokenFarm {
     DappToken public dappToken;
     DaiToken public daiToken;
 
+    address[] public stakers;
+    mapping(address => uint) public stakingBalance;
+    mapping(address => bool) public hasStaked;
+    mapping(address => bool) public isStaking;
+
     constructor(DappToken _dappToken, DaiToken _daiToken) public {
         dappToken = _dappToken;
         daiToken = _daiToken;
     }
+
+    function stakeTokens(uint _amount) public {
+
+        // Trasnfer Mock Dai tokens to this contract for staking
+        daiToken.transferFrom(msg.sender, address(this), _amount);
+
+        // Update staking balance
+        stakingBalance[msg.sender] = stakingBalance[msg.sender] + _amount;
+
+        // Add user to stakers array *only* if they haven't staked already
+        if(!hasStaked[msg.sender]) {
+            stakers.push(msg.sender);
+        }
+
+        // Update staking status
+        isStaking[msg.sender] = true;
+        hasStaked[msg.sender] = true;
+    }
+
+    // 2. Unstaking Tokens (Withdraw)
+
+    // 3. Issuing Tokens
 }

test/TokenFarm.test.js

@@ -52,4 +52,42 @@ contract('TokenFarm', ([owner, investor]) => {
     })
   })
 
+  describe('Farming tokens', async () => {
+
+    it('rewards investors for staking mDai tokens', async () => {
+      let result
+
+      // Check investor balance before staking
+      result = await daiToken.balanceOf(investor)
+      assert.equal(result.toString(), tokens('100'), 'investor Mock DAI wallet balance correct before staking')
+
+      // Stake Mock DAI Tokens
+      await daiToken.approve(tokenFarm.address, tokens('100'), { from: investor })
+      await tokenFarm.stakeTokens(tokens('100'), { from: investor })
+
+      // Check staking result
+      result = await daiToken.balanceOf(investor)
+      assert.equal(result.toString(), tokens('0'), 'investor Mock DAI wallet balance correct after staking')
+
+      result = await daiToken.balanceOf(tokenFarm.address)
+      assert.equal(result.toString(), tokens('100'), 'Token Farm Mock DAI balance correct after staking')
+
+      result = await tokenFarm.stakingBalance(investor)
+      assert.equal(result.toString(), tokens('100'), 'investor staking balance correct after staking')
+
+      result = await tokenFarm.isStaking(investor)
+      assert.equal(result.toString(), 'true', 'investor staking status correct after staking')
+    })
+  })
+
+
+
+
+
+
+
+
+
+
+
 })