38 test close a position partially

README.md

@@ -186,7 +186,7 @@ bytes memory loanDataBytes
 
 ```receiver``` is the user's address.
 
-```swapAmount``` defines how much of the position should be closed and is denominated in collateral tokens (e.g. rBTC on a iSUSD contract). If ```swapAmount >= collateral```, the complete position will be closed. Else ```(swapAmount/collateral) * principal``` will be swapped (partial closure).
+```swapAmount``` defines how much of the position should be closed and is denominated in collateral tokens (e.g. rBTC on a iSUSD contract). If ```swapAmount >= collateral```, the complete position will be closed. Else if `returnTokenIsCollateral == True` ```(swapAmount/collateral) * principal``` will be swapped (partial closure). Else the closure amount will be the principal's covered amount   
 
 ```returnTokenIsCollateral```  pass ```true``` if you want to withdraw remaining collateral + profit in collateral tokens (e.g. rBTC on a iSUSD contract), ```false``` if you want to withdraw it in loan tokens (e.g. sUSD on a iSUSD contract).
 

contracts/modules/LoanClosings.sol

@@ -115,7 +115,8 @@ contract LoanClosings is State, LoanClosingsEvents, VaultController, InterestUse
      * @param receiver the receiver of the remainder (unused collatral + profit)
      * @param swapAmount defines how much of the position should be closed and is denominated in collateral tokens. 
      *      If swapAmount >= collateral, the complete position will be closed. 
-     *      Else (swapAmount/collateral) * principal will be swapped (partial closure).
+     *      Else if returnTokenIsCollateral, (swapAmount/collateral) * principal will be swapped (partial closure).
+     *      Else coveredPrincipal
      * @param returnTokenIsCollateral defines if the remainder should be paid out in collateral tokens or underlying loan tokens
      * */
     function closeWithSwap(
@@ -487,7 +488,8 @@ contract LoanClosings is State, LoanClosingsEvents, VaultController, InterestUse
      * @param receiver the receiver of the remainder (unused collatral + profit)
      * @param swapAmount defines how much of the position should be closed and is denominated in collateral tokens. 
      *      If swapAmount >= collateral, the complete position will be closed. 
-     *      Else (swapAmount/collateral) * principal will be swapped (partial closure).
+     *      Else if returnTokenIsCollateral, (swapAmount/collateral) * principal will be swapped (partial closure).
+     *      Else coveredPrincipal
      * @param returnTokenIsCollateral defines if the remainder should be paid out in collateral tokens or underlying loan tokens
      * */
     function _closeWithSwap(