change integration scenario to always allow redeeming from self

  This makes it a lot easier for clients to deal with rewards. One can always give 'self' and simply let the backend decides whether or not rewards should be redeemed. For external wallets however, it could be quite counter-intuitive to succeed in the case there are no rewards in the target wallet so we still error in that case.

lib/core-integration/src/Test/Integration/Scenario/API/Shelley/Transactions.hs

@@ -1323,7 +1323,7 @@ spec = do
                     (.> (wSelf ^. #balance . #getApiT . #available))
                 ]
 
-    it "SHELLEY_TX_REDEEM_03 - Can't redeem rewards if none left" $ \ctx -> do
+    it "SHELLEY_TX_REDEEM_03 - Can't redeem rewards from other if none left" $ \ctx -> do
         (wOther, mw) <- rewardWallet ctx
         wSelf  <- fixtureWallet ctx
         addr:_ <- fmap (view #id) <$> listAddresses @n ctx wSelf
@@ -1356,7 +1356,27 @@ spec = do
             , expectErrorMessage errMsg403WithdrawalNotWorth
             ]
 
-    it "SHELLEY_TX_REDEEM_04 - Can't redeem rewards from unknown key" $ \ctx -> do
+    it "SHELLEY_TX_REDEEM_04 - Can always ask for self redemption" $ \ctx -> do
+        wSelf <- fixtureWallet ctx
+        addr:_ <- fmap (view #id) <$> listAddresses @n ctx wSelf
+
+        let payload = Json [json|{
+                "withdrawal": "self",
+                "payments": [{
+                    "address": #{addr},
+                    "amount": { "quantity": 1, "unit": "lovelace" }
+                }],
+                "passphrase": #{fixturePassphrase}
+            }|]
+
+        rTx <- request @(ApiTransaction n) ctx
+            (Link.createTransaction @'Shelley wSelf) Default payload
+        verify rTx
+            [ expectResponseCode HTTP.status202
+            , expectField #withdrawals (`shouldSatisfy` null)
+            ]
+
+    it "SHELLEY_TX_REDEEM_05 - Can't redeem rewards from unknown key" $ \ctx -> do
         wSelf  <- fixtureWallet ctx
         addr:_ <- fmap (view #id) <$> listAddresses @n ctx wSelf
 
@@ -1377,7 +1397,7 @@ spec = do
             , expectErrorMessage errMsg403WithdrawalNotWorth
             ]
 
-    it "SHELLEY_TX_REDEEM_05 - Can't redeem rewards using byron wallet" $ \ctx -> do
+    it "SHELLEY_TX_REDEEM_06 - Can't redeem rewards using byron wallet" $ \ctx -> do
         (wSelf, addrs) <- fixtureIcarusWalletAddrs @n ctx
         let addr = encodeAddress @n (head addrs)