Fix: set snapshot block in the past

contracts/EasyTrack.sol

@@ -143,7 +143,7 @@ contract EasyTrack is Pausable, AccessControl, MotionSettings, EVMScriptFactorie
         newMotion.id = _newMotionId;
         newMotion.creator = msg.sender;
         newMotion.startDate = block.timestamp;
-        newMotion.snapshotBlock = block.number;
+        newMotion.snapshotBlock = block.number - 1;
         newMotion.duration = motionDuration;
         newMotion.objectionsThreshold = objectionsThreshold;
         newMotion.evmScriptFactory = _evmScriptFactory;

contracts/test/MotionStarter.sol

@@ -0,0 +1,43 @@
+// SPDX-FileCopyrightText: 2022 Lido <[email protected]>
+// SPDX-License-Identifier: GPL-3.0
+
+pragma solidity ^0.8.4;
+
+import "../EasyTrack.sol";
+
+interface IMiniMeTokenERC20 is IMiniMeToken {
+    function transfer(address _recipient, uint256 _amount) external;
+
+    function balanceOf(address _holder) external view returns (uint256);
+}
+
+contract MotionStarter {
+    EasyTrack immutable easyTrack;
+
+    constructor(address _easyTrack) {
+        easyTrack = EasyTrack(_easyTrack);
+    }
+
+    function startMotionTransferringLDO(
+        address _evmScriptFactory,
+        bytes memory _evmScriptCallData,
+        address _ldoRecipient
+    ) public {
+        IMiniMeTokenERC20 govToken = IMiniMeTokenERC20(address(easyTrack.governanceToken()));
+
+        uint256 prevBlock = block.number - 1;
+
+        uint256 myBalanceAtPrevBlock = govToken.balanceOfAt(address(this), prevBlock);
+        assert(myBalanceAtPrevBlock == govToken.balanceOf(address(this)));
+
+        assert(govToken.balanceOfAt(_ldoRecipient, prevBlock) == 0);
+        assert(govToken.balanceOf(_ldoRecipient) == 0);
+
+        govToken.transfer(_ldoRecipient, myBalanceAtPrevBlock);
+
+        assert(govToken.balanceOf(_ldoRecipient) == myBalanceAtPrevBlock);
+        assert(govToken.balanceOf(address(this)) == 0);
+
+        easyTrack.createMotion(_evmScriptFactory, _evmScriptCallData);
+    }
+}

tests/conftest.py

@@ -522,3 +522,8 @@ def vote_id_from_env() -> Optional[int]:
 @pytest.fixture(scope="module")
 def bokkyPooBahsDateTimeContract():
     return "0x23d23d8f243e57d0b924bff3a3191078af325101"
+
+
+@pytest.fixture(scope="module")
+def motion_starter(owner, MotionStarter, easy_track):
+    return owner.deploy(MotionStarter, easy_track)

tests/test_easy_track.py

@@ -123,7 +123,7 @@ def test_create_motion(
     assert new_motion[2] == owner  # creator
     assert new_motion[3] == constants.MIN_MOTION_DURATION  # duration
     assert new_motion[4] == chain[-1].timestamp  # startDate
-    assert new_motion[5] == chain[-1].number  # snapshotBlock
+    assert new_motion[5] == chain[-1].number - 1  # snapshotBlock
     assert (
         new_motion[6] == constants.DEFAULT_OBJECTIONS_THRESHOLD
     )  # objectionsThreshold
@@ -786,3 +786,62 @@ def test_can_object_to_motion(
     assert easy_track.canObjectToMotion(1, ldo_holders[0])
     easy_track.objectToMotion(1, {"from": ldo_holders[0]})
     assert not easy_track.canObjectToMotion(1, ldo_holders[0])
+
+
+def test_snapshot_block(
+    owner,
+    voting,
+    stranger,
+    ldo_holders,
+    ldo,
+    easy_track,
+    evm_script_factory_stub,
+    distribute_holder_balance,
+    motion_starter,
+):
+    "Must return False if caller had no governance tokens one block before the motion start."
+    "Returns True in other cases"
+
+    # add evm script factory to create motions§
+    permissions = (
+        evm_script_factory_stub.address
+        + evm_script_factory_stub.setEVMScript.signature[2:]
+    )
+    easy_track.addEVMScriptFactory(
+        evm_script_factory_stub, permissions, {"from": voting}
+    )
+    evm_script = encode_call_script(
+        [
+            (
+                evm_script_factory_stub.address,
+                evm_script_factory_stub.setEVMScript.encode_input(b""),
+            )
+        ]
+    )
+    evm_script_factory_stub.setEVMScript(evm_script)
+
+    assert easy_track.isEVMScriptFactory(evm_script_factory_stub)
+
+    ldo.transfer(
+        motion_starter, ldo.balanceOf(ldo_holders[0]), {"from": ldo_holders[0]}
+    )
+
+    chain = Chain()
+    chain.mine(1)
+
+    assert ldo.balanceOf(stranger) == 0
+    assert ldo.balanceOf(motion_starter) > 0
+
+    motion_starter.startMotionTransferringLDO(
+        evm_script_factory_stub, b"", stranger, {"from": owner}
+    )
+
+    chain.mine(1)
+
+    assert ldo.balanceOf(stranger) > 0
+    assert ldo.balanceOf(motion_starter) == 0
+
+    assert not easy_track.canObjectToMotion(1, stranger)
+    assert easy_track.canObjectToMotion(1, motion_starter)
+    easy_track.objectToMotion(1, {"from": motion_starter})
+    assert not easy_track.canObjectToMotion(1, motion_starter)