Merge PR #2442: Support removal of accounts in account mapper

PENDING.md

@@ -111,6 +111,7 @@ FEATURES
   * [x/auth] \#2376 Remove FeePayer() from StdTx
   * [x/stake] [\#1672](https://github.com/cosmos/cosmos-sdk/issues/1672) Implement
   basis for the validator commission model.
+  * [x/auth] Support account removal in the account mapper.
 
 * Tendermint
 

x/auth/mapper.go

@@ -83,6 +83,13 @@ func (am AccountMapper) SetAccount(ctx sdk.Context, acc Account) {
 	store.Set(AddressStoreKey(addr), bz)
 }
 
+// RemoveAccount removes an account for the account mapper store.
+func (am AccountMapper) RemoveAccount(ctx sdk.Context, acc Account) {
+	addr := acc.GetAddress()
+	store := ctx.KVStore(am.key)
+	store.Delete(AddressStoreKey(addr))
+}
+
 // Implements sdk.AccountMapper.
 func (am AccountMapper) IterateAccounts(ctx sdk.Context, process func(Account) (stop bool)) {
 	store := ctx.KVStore(am.key)

x/auth/mapper_test.go

@@ -61,6 +61,44 @@ func TestAccountMapperGetSet(t *testing.T) {
 	require.Equal(t, newSequence, acc.GetSequence())
 }
 
+func TestAccountMapperRemoveAccount(t *testing.T) {
+	ms, capKey, _ := setupMultiStore()
+	cdc := codec.New()
+	RegisterBaseAccount(cdc)
+
+	// make context and mapper
+	ctx := sdk.NewContext(ms, abci.Header{}, false, log.NewNopLogger())
+	mapper := NewAccountMapper(cdc, capKey, ProtoBaseAccount)
+
+	addr1 := sdk.AccAddress([]byte("addr1"))
+	addr2 := sdk.AccAddress([]byte("addr2"))
+
+	// create accounts
+	acc1 := mapper.NewAccountWithAddress(ctx, addr1)
+	acc2 := mapper.NewAccountWithAddress(ctx, addr2)
+
+	accSeq1 := int64(20)
+	accSeq2 := int64(40)
+
+	acc1.SetSequence(accSeq1)
+	acc2.SetSequence(accSeq2)
+	mapper.SetAccount(ctx, acc1)
+	mapper.SetAccount(ctx, acc2)
+
+	acc1 = mapper.GetAccount(ctx, addr1)
+	require.NotNil(t, acc1)
+	require.Equal(t, accSeq1, acc1.GetSequence())
+
+	// remove one account
+	mapper.RemoveAccount(ctx, acc1)
+	acc1 = mapper.GetAccount(ctx, addr1)
+	require.Nil(t, acc1)
+
+	acc2 = mapper.GetAccount(ctx, addr2)
+	require.NotNil(t, acc2)
+	require.Equal(t, accSeq2, acc2.GetSequence())
+}
+
 func BenchmarkAccountMapperGetAccountFound(b *testing.B) {
 	ms, capKey, _ := setupMultiStore()
 	cdc := codec.New()