feat(x/authz): Add the GetAuthorization function. (#13047)

* [13027]: Create the GetAuthorization function (in the authz module).

* [13027]: Add unit tests for the new GetAuthorization function.

* [13027]: Add changelog entry.

CHANGELOG.md

@@ -42,6 +42,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 * (x/authz) [#12648](https://github.com/cosmos/cosmos-sdk/pull/12648) Add an allow list, an optional list of addresses allowed to receive bank assests via authz MsgSend grant.
 * (sdk.Coins) [#12627](https://github.com/cosmos/cosmos-sdk/pull/12627) Make a Denoms method on sdk.Coins.
 * (testutil) [#12973](https://github.com/cosmos/cosmos-sdk/pull/12973) Add generic `testutil.RandSliceElem` function which selects a random element from the list.
+* (x/authz) [#13047](https://github.com/cosmos/cosmos-sdk/pull/13047) Add a GetAuthorization function to the keeper.
 
 ### Improvements
 

x/authz/keeper/keeper.go

@@ -250,6 +250,25 @@ func (k Keeper) GetAuthorizations(ctx sdk.Context, grantee sdk.AccAddress, grant
 	return authorizations, nil
 }
 
+// GetAuthorization returns an Authorization and it's expiration time.
+// A nil Authorization is returned under the following circumstances:
+//	- No grant is found.
+//	- A grant is found, but it is expired.
+//	- There was an error getting the authorization from the grant.
+func (k Keeper) GetAuthorization(ctx sdk.Context, grantee sdk.AccAddress, granter sdk.AccAddress, msgType string) (authz.Authorization, *time.Time) {
+	grant, found := k.getGrant(ctx, grantStoreKey(grantee, granter, msgType))
+	if !found || (grant.Expiration != nil && grant.Expiration.Before(ctx.BlockHeader().Time)) {
+		return nil, nil
+	}
+
+	auth, err := grant.GetAuthorization()
+	if err != nil {
+		return nil, nil
+	}
+
+	return auth, grant.Expiration
+}
+
 // IterateGrants iterates over all authorization grants
 // This function should be used with caution because it can involve significant IO operations.
 // It should not be used in query or msg services without charging additional gas.

x/authz/keeper/keeper_test.go

@@ -59,7 +59,7 @@ func (s *TestSuite) SetupTest() {
 	s.baseApp.SetCMS(testCtx.CMS)
 	s.baseApp.SetInterfaceRegistry(s.encCfg.InterfaceRegistry)
 
-	s.addrs = simtestutil.CreateIncrementalAccounts(3)
+	s.addrs = simtestutil.CreateIncrementalAccounts(7)
 
 	// gomock initializations
 	ctrl := gomock.NewController(s.T())
@@ -392,6 +392,85 @@ func (s *TestSuite) TestDequeueAllGrantsQueue() {
 	require.Len(authzs, 1)
 }
 
+func (s *TestSuite) TestGetAuthorization() {
+	addr1 := s.addrs[3]
+	addr2 := s.addrs[4]
+	addr3 := s.addrs[5]
+	addr4 := s.addrs[6]
+
+	genAuthMulti := authz.NewGenericAuthorization(sdk.MsgTypeURL(&banktypes.MsgMultiSend{}))
+	genAuthSend := authz.NewGenericAuthorization(sdk.MsgTypeURL(&banktypes.MsgSend{}))
+	sendAuth := banktypes.NewSendAuthorization(coins10, nil)
+
+	start := s.ctx.BlockHeader().Time
+	expired := start.Add(time.Duration(1) * time.Second)
+	notExpired := start.Add(time.Duration(5) * time.Hour)
+
+	s.Require().NoError(s.authzKeeper.SaveGrant(s.ctx, addr1, addr2, genAuthMulti, nil), "creating grant 1->2")
+	s.Require().NoError(s.authzKeeper.SaveGrant(s.ctx, addr1, addr3, genAuthSend, &expired), "creating grant 1->3")
+	s.Require().NoError(s.authzKeeper.SaveGrant(s.ctx, addr1, addr4, sendAuth, &notExpired), "creating grant 1->4")
+	// Without access to private keeper methods, I don't know how to save a grant with an invalid authorization.
+	newCtx := s.ctx.WithBlockTime(start.Add(time.Duration(1) * time.Minute))
+
+	tests := []struct {
+		name    string
+		grantee sdk.AccAddress
+		granter sdk.AccAddress
+		msgType string
+		expAuth authz.Authorization
+		expExp  *time.Time
+	}{
+		{
+			name:    "grant has nil exp and is returned",
+			grantee: addr1,
+			granter: addr2,
+			msgType: genAuthMulti.MsgTypeURL(),
+			expAuth: genAuthMulti,
+			expExp:  nil,
+		},
+		{
+			name:    "grant is expired not returned",
+			grantee: addr1,
+			granter: addr3,
+			msgType: genAuthSend.MsgTypeURL(),
+			expAuth: nil,
+			expExp:  nil,
+		},
+		{
+			name:    "grant is not expired and is returned",
+			grantee: addr1,
+			granter: addr4,
+			msgType: sendAuth.MsgTypeURL(),
+			expAuth: sendAuth,
+			expExp:  &notExpired,
+		},
+		{
+			name:    "grant is not expired but wrong msg type returns nil",
+			grantee: addr1,
+			granter: addr4,
+			msgType: genAuthMulti.MsgTypeURL(),
+			expAuth: nil,
+			expExp:  nil,
+		},
+		{
+			name:    "no grant exists between the two",
+			grantee: addr2,
+			granter: addr3,
+			msgType: genAuthSend.MsgTypeURL(),
+			expAuth: nil,
+			expExp:  nil,
+		},
+	}
+
+	for _, tc := range tests {
+		s.Run(tc.name, func() {
+			actAuth, actExp := s.authzKeeper.GetAuthorization(newCtx, tc.grantee, tc.granter, tc.msgType)
+			s.Assert().Equal(tc.expAuth, actAuth, "authorization")
+			s.Assert().Equal(tc.expExp, actExp, "expiration")
+		})
+	}
+}
+
 func TestTestSuite(t *testing.T) {
 	suite.Run(t, new(TestSuite))
 }