feat: added TaskAssigned event to Linguo

Author: hbarcelos

contracts/standard/arbitration/Linguo.sol

@@ -80,6 +80,14 @@ contract Linguo is Arbitrable {
      */
     event TaskCreated(uint indexed _taskID, address indexed _requester, uint _timestamp);
 
+    /** @dev To be emitted when a translator assigns the task to himself.
+     *  @param _taskID The ID of the newly created task.
+     *  @param _translator The address that assigned to the task.
+     *  @param _price The task price at the moment it was assigned.
+     *  @param _timestamp When the task was assigned.
+     */
+    event TaskAssigned(uint indexed _taskID, address indexed _translator, uint _price, uint _timestamp);
+
     /** @dev To be emitted when a translation is submitted.
      *  @param _taskID The ID of the respective task.
      *  @param _translator The address that performed the translation.
@@ -250,6 +258,8 @@ contract Linguo is Arbitrable {
 
         remainder = msg.value - deposit;
         msg.sender.send(remainder);
+
+        emit TaskAssigned(_taskID, msg.sender, price, now);
     }
 
     /** @dev Submits translated text for a specific task.

test/linguo.js

@@ -223,6 +223,20 @@ contract('Linguo', function(accounts) {
     )
   })
 
+  it('Should emit TaskAssigned event after assigning to the task', async () => {
+    const requiredDeposit = (await linguo.getDepositValue(0)).toNumber()
+    const assignTx = await linguo.assignTask(0, {
+      from: translator,
+      value: requiredDeposit + 1e17
+    })
+
+    assert.equal(
+      assignTx.logs[0].event,
+      'TaskAssigned',
+      'The TaskAssigned event was not emitted'
+    )
+  })
+
   it('Should reimburse requester leftover price after assigning the task and set correct values', async () => {
     const oldBalance = await web3.eth.getBalance(requester)