payroll: add payday remainders as accrued salary

aragon · Jul 5, 2019 · da8fdd2 · da8fdd2
1 parent d28394c
commit da8fdd2
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Showing 2 changed files with 182 additions and 148 deletions.
diff --git a/future-apps/payroll/contracts/Payroll.sol b/future-apps/payroll/contracts/Payroll.sol
@@ -655,7 +655,41 @@ contract Payroll is EtherTokenConstant, IForwarder, IsContract, AragonApp {
             // No need to use SafeMath here as we already know _paymentAmount > accruedSalary
             currentSalaryPaid = _paymentAmount - accruedSalary;
         }
-        employee.lastPayroll = _getLastPayrollDate(_employeeId, currentSalaryPaid);
+        _updateEmployeeLastPayrollDate(_employeeId, currentSalaryPaid);
+    }
+
+    /**
+     * @dev Update the last payroll date for an employee based on the requested payment amount. If the requested amount
+     *      cannot be represented by a multiple of the employee's salary per second, it will be added as accrued salary.
+     * @param _employeeId Employee's identifier
+     * @param _paidAmount Requested amount to be paid to the employee
+     */
+    function _updateEmployeeLastPayrollDate(uint256 _employeeId, uint256 _paidAmount) internal {
+        Employee storage employee = employees[_employeeId];
+
+        uint256 timeDiff = _paidAmount.div(employee.denominationTokenSalary);
+
+        // We check if the division was perfect, and if not, take its ceiling to avoid giving away tiny amounts of
+        // salary and add the remainder to the accrued salary.
+        if (timeDiff.mul(employee.denominationTokenSalary) != _paidAmount) {
+            timeDiff = timeDiff.add(1);
+            // No need to use SafeMath here, we already now that _paidAmount is lower than its ceil
+            uint256 remainder = timeDiff.mul(employee.denominationTokenSalary) - _paidAmount;
+
+            uint256 currentAccruedSalary = employee.accruedSalary;
+            uint256 newAccruedSalary = currentAccruedSalary + remainder;
+            if (newAccruedSalary < currentAccruedSalary) {
+                newAccruedSalary = MAX_UINT256;
+            }
+            employee.accruedSalary = newAccruedSalary;
+        }
+
+        uint256 lastPayrollDate = uint256(employee.lastPayroll).add(timeDiff);
+        // Even though this function should never receive a _paidAmount value that would result in
+        // the lastPayrollDate being higher than the current time, let's double check to be safe
+        require(lastPayrollDate <= uint256(getTimestamp64()), ERROR_LAST_PAYROLL_DATE_TOO_BIG);
+        // Already know lastPayrollDate must fit in uint64 from above
+        employee.lastPayroll = uint64(lastPayrollDate);
     }
 
     /**
@@ -726,34 +760,6 @@ contract Payroll is EtherTokenConstant, IForwarder, IsContract, AragonApp {
         return uint256(xrt);
     }
 
-    /**
-     * @dev Calculate the new last payroll date for an employee based on the requested payment amount
-     * @param _employeeId Employee's identifier
-     * @param _paidAmount Requested amount to be paid to the employee
-     * @return The new last payroll timestamp in seconds based on the requested payment amount
-     */
-    function _getLastPayrollDate(uint256 _employeeId, uint256 _paidAmount) internal view returns (uint64) {
-        Employee storage employee = employees[_employeeId];
-
-        uint256 timeDiff = _paidAmount.div(employee.denominationTokenSalary);
-
-        // We check if the division was perfect, and if not, take its ceiling to avoid giving away
-        // tiny amounts of salary.
-        // Employees may lose up to a second's worth of payroll if they use the "request partial
-        // amount" feature or reach salary amounts that get capped by uint max.
-        if (timeDiff.mul(employee.denominationTokenSalary) != _paidAmount) {
-            timeDiff = timeDiff.add(1);
-        }
-
-        uint256 lastPayrollDate = uint256(employee.lastPayroll).add(timeDiff);
-
-        // Even though this function should never receive a _paidAmount value that would result in
-        // the lastPayrollDate being higher than the current time, let's double check to be safe
-        require(lastPayrollDate <= uint256(getTimestamp64()), ERROR_LAST_PAYROLL_DATE_TOO_BIG);
-        // Already know lastPayrollDate must fit in uint64 from above
-        return uint64(lastPayrollDate);
-    }
-
     /**
      * @dev Get owed salary since last payroll for an employee
      * @param _employeeId Employee's identifier