add balance transfer tests

Add tests to show the error types of different impossible balance transfers.

Since it's only tests describing the current behavior, I merge this without review. We can change the behavior in an other MR.

closes #135 (closed)

runtime/gdev/tests/balance_tests.rs

+// Copyright 2021 Axiom-Team
+//
+// This file is part of Duniter-v2S.
+//
+// Duniter-v2S is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, version 3 of the License.
+//
+// Duniter-v2S is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with Duniter-v2S. If not, see <https://www.gnu.org/licenses/>.
+
+// this file is for balance transfer tests (split from integration_tests)
+
+mod common;
+
+use common::*;
+use frame_support::{assert_noop, assert_ok};
+use gdev_runtime::*;
+use sp_keyring::AccountKeyring;
+
+/// test currency transfer
+/// (does not take fees into account because it's only calls, not extrinsics)
+#[test]
+fn test_transfer() {
+    ExtBuilder::new(1, 3, 4)
+        .with_initial_balances(vec![
+            (AccountKeyring::Alice.to_account_id(), 10_000),
+            (AccountKeyring::Eve.to_account_id(), 10_000),
+        ])
+        .build()
+        .execute_with(|| {
+            // Alice gives 500 to Eve
+            assert_ok!(Balances::transfer_allow_death(
+                frame_system::RawOrigin::Signed(AccountKeyring::Alice.to_account_id()).into(),
+                AccountKeyring::Eve.to_account_id().into(),
+                500
+            ));
+            // check amounts
+            assert_eq!(
+                Balances::free_balance(AccountKeyring::Alice.to_account_id()),
+                10_000 - 500
+            );
+            assert_eq!(
+                Balances::free_balance(AccountKeyring::Eve.to_account_id()),
+                10_000 + 500
+            );
+        })
+}
+
+/// test balance transfer
+#[test]
+fn test_transfer() {
+    ExtBuilder::new(1, 3, 4)
+        .with_initial_balances(vec![(AccountKeyring::Alice.to_account_id(), 600)])
+        .build()
+        .execute_with(|| {
+            run_to_block(1);
+            assert_ok!(Balances::transfer_allow_death(
+                frame_system::RawOrigin::Signed(AccountKeyring::Alice.to_account_id()).into(),
+                AccountKeyring::Dave.to_account_id().into(),
+                500
+            ));
+        })
+}
+
+/// test balance transfer without enough balance (would prefer TokenError::BelowMinimum or NotExpendable)
+#[test]
+fn test_transfer_not_enough() {
+    ExtBuilder::new(1, 3, 4)
+        .with_initial_balances(vec![(AccountKeyring::Alice.to_account_id(), 599)])
+        .build()
+        .execute_with(|| {
+            run_to_block(1);
+            assert_noop!(
+                Balances::transfer_allow_death(
+                    frame_system::RawOrigin::Signed(AccountKeyring::Alice.to_account_id()).into(),
+                    AccountKeyring::Dave.to_account_id().into(),
+                    500
+                ),
+                sp_runtime::TokenError::Frozen
+            );
+        })
+}
+
+/// test balance transfer without enough balance (would prefer TokenError::FundsUnavailable)
+#[test]
+fn test_transfer_underflow() {
+    ExtBuilder::new(1, 3, 4)
+        .with_initial_balances(vec![(AccountKeyring::Alice.to_account_id(), 499)])
+        .build()
+        .execute_with(|| {
+            run_to_block(1);
+            assert_noop!(
+                Balances::transfer_allow_death(
+                    frame_system::RawOrigin::Signed(AccountKeyring::Alice.to_account_id()).into(),
+                    AccountKeyring::Dave.to_account_id().into(),
+                    500
+                ),
+                sp_runtime::ArithmeticError::Underflow
+            );
+        })
+}
+
+/// test balance transfer without enough balance
+#[test]
+fn test_transfer_funds_unavailable() {
+    ExtBuilder::new(1, 3, 4)
+        .with_initial_balances(vec![
+            (AccountKeyring::Alice.to_account_id(), 499),
+            (AccountKeyring::Bob.to_account_id(), 200),
+        ])
+        .build()
+        .execute_with(|| {
+            run_to_block(1);
+            assert_noop!(
+                Balances::transfer_allow_death(
+                    frame_system::RawOrigin::Signed(AccountKeyring::Alice.to_account_id()).into(),
+                    AccountKeyring::Dave.to_account_id().into(),
+                    500
+                ),
+                sp_runtime::TokenError::FundsUnavailable
+            );
+        })
+}