[FOLD] update unit test

src/test/app/AMM_test.cpp

@@ -4798,8 +4798,11 @@ struct AMM_test : public jtx::AMMTest
         auto test = [&](FeatureBitset features,
                         TER const& err1,
                         TER const& err2,
+                        TER const& err3,
+                        TER const& err4,
                         std::uint16_t tfee,
-                        bool closeLedger) {
+                        bool closeLedger,
+                        std::optional<std::uint16_t> extra = std::nullopt) {
             Env env(*this, features);
             fund(env, gw, {alice}, XRP(1'000), {USD(10)});
             AMM amm(
@@ -4808,32 +4811,86 @@ struct AMM_test : public jtx::AMMTest
                 XRP(10),
                 USD(10),
                 {.tfee = tfee, .close = closeLedger});
-            amm.deposit(alice, USD(5));
+            amm.deposit(alice, USD(10), XRP(10));
             amm.vote(
-                alice, 0, std::nullopt, std::nullopt, std::nullopt, ter(err1));
-            amm.withdraw(gw, USD(10), std::nullopt, std::nullopt, ter(err2));
+                alice,
+                tfee,
+                std::nullopt,
+                std::nullopt,
+                std::nullopt,
+                ter(err1));
+            amm.withdraw(gw, USD(1), std::nullopt, std::nullopt, ter(err2));
+            // with the amendment disabled and ledger not closed,
+            // second vote succeeds if the first vote sets the trading fee
+            // to non-zero; if the first vote sets the trading fee to >0 && <9
+            // then the second withdraw succeeds if the second vote sets
+            // the trading fee so that the discounted fee is non-zero
+            amm.vote(
+                alice, 20, std::nullopt, std::nullopt, std::nullopt, ter(err3));
+            amm.withdraw(gw, USD(2), std::nullopt, std::nullopt, ter(err4));
         };
 
         // ledger is closed after each transaction, vote/withdraw don't fail
-        // regardless if the amendment is enabled or not
-        test(all, tesSUCCESS, tesSUCCESS, 0, true);
-        test(all - fixInnerObjTemplDefault, tesSUCCESS, tesSUCCESS, 0, true);
+        // regardless whether the amendment is enabled or not
+        test(all, tesSUCCESS, tesSUCCESS, tesSUCCESS, tesSUCCESS, 0, true);
+        test(
+            all - fixInnerObjTemplDefault,
+            tesSUCCESS,
+            tesSUCCESS,
+            tesSUCCESS,
+            tesSUCCESS,
+            0,
+            true);
         // ledger is not closed after each transaction
         // vote/withdraw don't fail if the amendment is enabled
-        test(all, tesSUCCESS, tesSUCCESS, 0, false);
+        test(all, tesSUCCESS, tesSUCCESS, tesSUCCESS, tesSUCCESS, 0, false);
         // vote/withdraw fail if the amendment is not enabled
+        // second vote/withdraw still fail: second vote fails because
+        // the initial trading fee is 0, consequently second withdraw fails
+        // because the second vote fails
         test(
             all - fixInnerObjTemplDefault,
             tefEXCEPTION,
             tefEXCEPTION,
+            tefEXCEPTION,
+            tefEXCEPTION,
             0,
             false);
-        // if non-zero fee then vote/withdraw don't fail whether the ledger
-        // is closed or not and the amendment enabled or not
-        test(all, tesSUCCESS, tesSUCCESS, 100, true);
-        test(all - fixInnerObjTemplDefault, tesSUCCESS, tesSUCCESS, 100, true);
-        test(all, tesSUCCESS, tesSUCCESS, 100, false);
-        test(all - fixInnerObjTemplDefault, tesSUCCESS, tesSUCCESS, 100, false);
+        // if non-zero trading/discounted fee then vote/withdraw
+        // don't fail whether the ledger is closed or not and
+        // the amendment is enabled or not
+        test(all, tesSUCCESS, tesSUCCESS, tesSUCCESS, tesSUCCESS, 10, true);
+        test(
+            all - fixInnerObjTemplDefault,
+            tesSUCCESS,
+            tesSUCCESS,
+            tesSUCCESS,
+            tesSUCCESS,
+            10,
+            true);
+        test(all, tesSUCCESS, tesSUCCESS, tesSUCCESS, tesSUCCESS, 10, false);
+        test(
+            all - fixInnerObjTemplDefault,
+            tesSUCCESS,
+            tesSUCCESS,
+            tesSUCCESS,
+            tesSUCCESS,
+            10,
+            false);
+        // non-zero trading fee but discounted fee is 0, vote doesn't fail
+        // but withdraw fails
+        test(all, tesSUCCESS, tesSUCCESS, tesSUCCESS, tesSUCCESS, 9, false);
+        // second vote sets the trading fee to non-zero, consequently
+        // second withdraw doesn't fail even if the amendment is not
+        // enabled and the ledger is not closed
+        test(
+            all - fixInnerObjTemplDefault,
+            tesSUCCESS,
+            tefEXCEPTION,
+            tesSUCCESS,
+            tesSUCCESS,
+            9,
+            false);
     }
 
     void