Merge pull request boscore#7 from EOSIO/retire-tokens

retire tokens boscore#6
vlbos · Jul 10, 2018 · e96f801 · e96f801
2 parents 90f8e38 + a8ac830
commit e96f801
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diff --git a/eosio.token/abi/eosio.token.abi b/eosio.token/abi/eosio.token.abi
@@ -28,6 +28,13 @@
         {"name":"quantity", "type":"asset"},
         {"name":"memo", "type":"string"}
      ]
+  },{
+     "name": "retire",
+     "base": "",
+     "fields": [
+        {"name":"quantity", "type":"asset"},
+        {"name":"memo", "type":"string"}
+     ]
   },{
      "name": "close",
      "base": "",
@@ -59,6 +66,10 @@
       "name": "issue",
       "type": "issue",
       "ricardian_contract": ""
+    },{
+      "name": "retire",
+      "type": "retire",
+      "ricardian_contract": ""
     }, {
       "name": "create",
       "type": "create",

diff --git a/eosio.token/include/eosio.token/eosio.token.hpp b/eosio.token/include/eosio.token/eosio.token.hpp
@@ -26,6 +26,8 @@ namespace eosio {
 
          void issue( account_name to, asset quantity, string memo );
 
+         void retire( asset quantity, string memo );
+
          void transfer( account_name from,
                         account_name to,
                         asset        quantity,

diff --git a/eosio.token/src/eosio.token.cpp b/eosio.token/src/eosio.token.cpp
@@ -59,6 +59,31 @@ void token::issue( account_name to, asset quantity, string memo )
     }
 }
 
+void token::retire( asset quantity, string memo )
+{
+    auto sym = quantity.symbol;
+    eosio_assert( sym.is_valid(), "invalid symbol name" );
+    eosio_assert( memo.size() <= 256, "memo has more than 256 bytes" );
+
+    auto sym_name = sym.name();
+    stats statstable( _self, sym_name );
+    auto existing = statstable.find( sym_name );
+    eosio_assert( existing != statstable.end(), "token with symbol does not exist" );
+    const auto& st = *existing;
+
+    require_auth( st.issuer );
+    eosio_assert( quantity.is_valid(), "invalid quantity" );
+    eosio_assert( quantity.amount > 0, "must retire positive quantity" );
+
+    eosio_assert( quantity.symbol == st.supply.symbol, "symbol precision mismatch" );
+
+    statstable.modify( st, 0, [&]( auto& s ) {
+       s.supply -= quantity;
+    });
+
+    sub_balance( st.issuer, quantity );
+}
+
 void token::transfer( account_name from,
                       account_name to,
                       asset        quantity,
@@ -121,4 +146,4 @@ void token::close( account_name owner, symbol_type symbol ) {
 
 } /// namespace eosio
 
-EOSIO_ABI( eosio::token, (create)(issue)(transfer)(close) )
+EOSIO_ABI( eosio::token, (create)(issue)(transfer)(close)(retire) )
diff --git a/tests/eosio.token_tests.cpp b/tests/eosio.token_tests.cpp
@@ -80,6 +80,14 @@ class eosio_token_tester : public tester {
       );
    }
 
+   action_result retire( account_name issuer, asset quantity, string memo ) {
+      return push_action( issuer, N(retire), mvo()
+           ( "quantity", quantity)
+           ( "memo", memo)
+      );
+
+   }
+
    action_result transfer( account_name from,
                   account_name to,
                   asset        quantity,
@@ -225,6 +233,63 @@ BOOST_FIXTURE_TEST_CASE( issue_tests, eosio_token_tester ) try {
 
 } FC_LOG_AND_RETHROW()
 
+BOOST_FIXTURE_TEST_CASE( retire_tests, eosio_token_tester ) try {
+
+   auto token = create( N(alice), asset::from_string("1000.000 TKN"));
+   produce_blocks(1);
+
+   BOOST_REQUIRE_EQUAL( success(), issue( N(alice), N(alice), asset::from_string("500.000 TKN"), "hola" ) );
+
+   auto stats = get_stats("3,TKN");
+   REQUIRE_MATCHING_OBJECT( stats, mvo()
+      ("supply", "500.000 TKN")
+      ("max_supply", "1000.000 TKN")
+      ("issuer", "alice")
+   );
+
+   auto alice_balance = get_account(N(alice), "3,TKN");
+   REQUIRE_MATCHING_OBJECT( alice_balance, mvo()
+      ("balance", "500.000 TKN")
+   );
+
+   BOOST_REQUIRE_EQUAL( success(), retire( N(alice), asset::from_string("200.000 TKN"), "hola" ) );
+   stats = get_stats("3,TKN");
+   REQUIRE_MATCHING_OBJECT( stats, mvo()
+      ("supply", "300.000 TKN")
+      ("max_supply", "1000.000 TKN")
+      ("issuer", "alice")
+   );
+   alice_balance = get_account(N(alice), "3,TKN");
+   REQUIRE_MATCHING_OBJECT( alice_balance, mvo()
+      ("balance", "300.000 TKN")
+   );
+
+   //should fail to retire more than current supply
+   BOOST_REQUIRE_EQUAL( wasm_assert_msg("overdrawn balance"), retire( N(alice), asset::from_string("500.000 TKN"), "hola" ) );
+
+   BOOST_REQUIRE_EQUAL( success(), transfer( N(alice), N(bob), asset::from_string("200.000 TKN"), "hola" ) );
+   //should fail to retire since tokens are not on the issuer's balance
+   BOOST_REQUIRE_EQUAL( wasm_assert_msg("overdrawn balance"), retire( N(alice), asset::from_string("300.000 TKN"), "hola" ) );
+   //transfer tokens back
+   BOOST_REQUIRE_EQUAL( success(), transfer( N(bob), N(alice), asset::from_string("200.000 TKN"), "hola" ) );
+
+   BOOST_REQUIRE_EQUAL( success(), retire( N(alice), asset::from_string("300.000 TKN"), "hola" ) );
+   stats = get_stats("3,TKN");
+   REQUIRE_MATCHING_OBJECT( stats, mvo()
+      ("supply", "0.000 TKN")
+      ("max_supply", "1000.000 TKN")
+      ("issuer", "alice")
+   );
+   alice_balance = get_account(N(alice), "3,TKN");
+   REQUIRE_MATCHING_OBJECT( alice_balance, mvo()
+      ("balance", "0.000 TKN")
+   );
+
+   //trying to retire tokens with zero supply
+   BOOST_REQUIRE_EQUAL( wasm_assert_msg("overdrawn balance"), retire( N(alice), asset::from_string("1.000 TKN"), "hola" ) );
+
+} FC_LOG_AND_RETHROW()
+
 BOOST_FIXTURE_TEST_CASE( transfer_tests, eosio_token_tester ) try {
 
    auto token = create( N(alice), asset::from_string("1000 CERO"));