git.delta.rocks / unique-network / refs/commits / c8ad2c279e20

--- a/pallets/fungible/src/lib.rs
+++ b/pallets/fungible/src/lib.rs
@@ -379,7 +379,7 @@
 		let balance_from = <Balance<T>>::get((collection.id, from))
 			.checked_sub(amount)
 			.ok_or(<CommonError<T>>::TokenValueTooLow)?;
-		let balance_to = if from != to {
+		let balance_to = if from != to && amount != 0 {
 			Some(
 				<Balance<T>>::get((collection.id, to))
 					.checked_add(amount)
@@ -391,16 +391,17 @@
 
 		// =========
 
-		<PalletStructure<T>>::nest_if_sent_to_token(
-			from.clone(),
-			to,
-			collection.id,
-			TokenId::default(),
-			nesting_budget,
-		)?;
-
 		if let Some(balance_to) = balance_to {
-			// from != to
+			// from != to && amount != 0
+
+			<PalletStructure<T>>::nest_if_sent_to_token(
+				from.clone(),
+				to,
+				collection.id,
+				TokenId::default(),
+				nesting_budget,
+			)?;
+
 			if balance_from == 0 {
 				<Balance<T>>::remove((collection.id, from));
 				<PalletStructure<T>>::unnest_if_nested(from, collection.id, TokenId::default());

--- a/pallets/nonfungible/src/common.rs
+++ b/pallets/nonfungible/src/common.rs
@@ -291,6 +291,7 @@
 				<CommonWeights<T>>::burn_item(),
 			)
 		} else {
+			<Pallet<T>>::check_token_immediate_ownership(self, token, &sender)?;
 			Ok(().into())
 		}
 	}
@@ -320,6 +321,7 @@
 				<CommonWeights<T>>::transfer(),
 			)
 		} else {
+			<Pallet<T>>::check_token_immediate_ownership(self, token, &from)?;
 			Ok(().into())
 		}
 	}
@@ -360,6 +362,8 @@
 				<CommonWeights<T>>::transfer_from(),
 			)
 		} else {
+			<Pallet<T>>::check_allowed(self, &sender, &from, token, nesting_budget)?;
+
 			Ok(().into())
 		}
 	}
@@ -380,6 +384,8 @@
 				<CommonWeights<T>>::burn_from(),
 			)
 		} else {
+			<Pallet<T>>::check_allowed(self, &sender, &from, token, nesting_budget)?;
+
 			Ok(().into())
 		}
 	}

--- a/pallets/nonfungible/src/lib.rs
+++ b/pallets/nonfungible/src/lib.rs
@@ -814,6 +814,20 @@
 		<PalletCommon<T>>::set_property_permission(collection, sender, permission)
 	}
 
+	pub fn check_token_immediate_ownership(
+		collection: &NonfungibleHandle<T>,
+		token: TokenId,
+		possible_owner: &T::CrossAccountId,
+	) -> DispatchResult {
+		let token_data =
+			<TokenData<T>>::get((collection.id, token)).ok_or(<CommonError<T>>::TokenNotFound)?;
+		ensure!(
+			&token_data.owner == possible_owner,
+			<CommonError<T>>::NoPermission
+		);
+		Ok(())
+	}
+
 	/// Transfer NFT token from one account to another.
 	///
 	/// `from` account stops being the owner and `to` account becomes the owner of the token.

--- a/pallets/refungible/src/erc.rs
+++ b/pallets/refungible/src/erc.rs
@@ -34,6 +34,7 @@
 	CollectionHandle, CollectionPropertyPermissions, CommonCollectionOperations,
 	erc::{CommonEvmHandler, CollectionCall, static_property::key},
 	eth::EthCrossAccount,
+	Error as CommonError,
 };
 use pallet_evm::{account::CrossAccountId, PrecompileHandle};
 use pallet_evm_coder_substrate::{call, dispatch_to_evm};
@@ -508,6 +509,13 @@
 ) -> Result<()> {
 	collection.consume_store_reads(1)?;
 	let total_supply = <TotalSupply<T>>::get((collection.id, token));
+
+	if owner_balance == 0 {
+		return Err(dispatch_to_evm::<T>(
+			<CommonError<T>>::MustBeTokenOwner.into(),
+		));
+	}
+
 	if total_supply != owner_balance {
 		return Err("token has multiple owners".into());
 	}

--- a/pallets/refungible/src/lib.rs
+++ b/pallets/refungible/src/lib.rs
@@ -452,6 +452,10 @@
 		token: TokenId,
 		amount: u128,
 	) -> DispatchResult {
+		if <Balance<T>>::get((collection.id, token, owner)) == 0 {
+			return Err(<CommonError<T>>::TokenValueTooLow.into());
+		}
+
 		let total_supply = <TotalSupply<T>>::get((collection.id, token))
 			.checked_sub(amount)
 			.ok_or(<CommonError<T>>::TokenValueTooLow)?;
@@ -739,12 +743,17 @@
 		<PalletCommon<T>>::ensure_correct_receiver(to)?;
 
 		let initial_balance_from = <Balance<T>>::get((collection.id, token, from));
+
+		if initial_balance_from == 0 {
+			return Err(<CommonError<T>>::TokenValueTooLow.into());
+		}
+
 		let updated_balance_from = initial_balance_from
 			.checked_sub(amount)
 			.ok_or(<CommonError<T>>::TokenValueTooLow)?;
 		let mut create_target = false;
 		let from_to_differ = from != to;
-		let updated_balance_to = if from != to {
+		let updated_balance_to = if from != to && amount != 0 {
 			let old_balance = <Balance<T>>::get((collection.id, token, to));
 			if old_balance == 0 {
 				create_target = true;
@@ -786,16 +795,17 @@
 
 		// =========
 
-		<PalletStructure<T>>::nest_if_sent_to_token(
-			from.clone(),
-			to,
-			collection.id,
-			token,
-			nesting_budget,
-		)?;
+		if let Some(updated_balance_to) = updated_balance_to {
+			// from != to && amount != 0
+
+			<PalletStructure<T>>::nest_if_sent_to_token(
+				from.clone(),
+				to,
+				collection.id,
+				token,
+				nesting_budget,
+			)?;
 
-		if let Some(updated_balance_to) = updated_balance_to {
-			// from != to
 			if updated_balance_from == 0 {
 				<Balance<T>>::remove((collection.id, token, from));
 				<PalletStructure<T>>::unnest_if_nested(from, collection.id, token);

--- a/tests/src/burnItem.test.ts
+++ b/tests/src/burnItem.test.ts
@@ -140,6 +140,31 @@
     await expect(token.burn(bob)).to.be.rejectedWith('common.NoPermission');
   });
 
+  itSub.ifWithPallets('RFT: cannot burn non-owned token pieces', [Pallets.ReFungible], async ({helper}) => {
+    const collection = await helper.rft.mintCollection(alice);
+    const aliceToken = await collection.mintToken(alice, 10n, {Substrate: alice.address});
+    const bobToken = await collection.mintToken(alice, 10n, {Substrate: bob.address});
+
+    // 1. Cannot burn non-owned token:
+    await expect(bobToken.burn(alice, 0n)).to.be.rejectedWith('common.TokenValueTooLow');
+    await expect(bobToken.burn(alice, 5n)).to.be.rejectedWith('common.TokenValueTooLow');
+    // 2. Cannot burn non-existing token:
+    await expect(helper.rft.burnToken(alice, 99999, 10)).to.be.rejectedWith('common.CollectionNotFound');
+    await expect(helper.rft.burnToken(alice, collection.collectionId, 99999)).to.be.rejectedWith('common.TokenValueTooLow');
+    // 3. Can burn zero amount of owned tokens (EIP-20)
+    await aliceToken.burn(alice, 0n);
+
+    // 4. Storage is not corrupted:
+    expect(await aliceToken.getTop10Owners()).to.deep.eq([{Substrate: alice.address}]);
+    expect(await bobToken.getTop10Owners()).to.deep.eq([{Substrate: bob.address}]);
+
+    // 4.1 Tokens can be transfered:
+    await aliceToken.transfer(alice, {Substrate: bob.address}, 10n);
+    await bobToken.transfer(bob, {Substrate: alice.address}, 10n);
+    expect(await aliceToken.getTop10Owners()).to.deep.eq([{Substrate: bob.address}]);
+    expect(await bobToken.getTop10Owners()).to.deep.eq([{Substrate: alice.address}]);
+  });
+
   itSub('Transfer a burned token', async ({helper}) => {
     const collection = await helper.nft.mintCollection(alice);
     const token = await collection.mintToken(alice);
@@ -155,4 +180,48 @@
     await expect(collection.burnTokens(alice, 11n)).to.be.rejectedWith('common.TokenValueTooLow');
     expect(await collection.getBalance({Substrate: alice.address})).to.eq(10n);
   });
+
+  itSub('Zero burn NFT', async ({helper}) => {
+    const collection = await helper.nft.mintCollection(alice, {name: 'Coll', description: 'Desc', tokenPrefix: 'T'});
+    const tokenAlice = await collection.mintToken(alice, {Substrate: alice.address});
+    const tokenBob = await collection.mintToken(alice, {Substrate: bob.address});
+    
+    // 1. Zero burn of own tokens allowed:
+    await helper.executeExtrinsic(alice, 'api.tx.unique.burnItem', [collection.collectionId, tokenAlice.tokenId, 0]);
+    // 2. Zero burn of non-owned tokens not allowed:
+    await expect(helper.executeExtrinsic(alice, 'api.tx.unique.burnItem', [collection.collectionId, tokenBob.tokenId, 0])).to.be.rejectedWith('common.NoPermission');
+    // 3. Zero burn of non-existing tokens not allowed:
+    await expect(helper.executeExtrinsic(alice, 'api.tx.unique.burnItem', [collection.collectionId, 9999, 0])).to.be.rejectedWith('common.TokenNotFound');
+    expect(await tokenAlice.doesExist()).to.be.true;
+    expect(await tokenAlice.getOwner()).to.deep.eq({Substrate: alice.address});
+    expect(await tokenBob.getOwner()).to.deep.eq({Substrate: bob.address});
+    // 4. Storage is not corrupted:
+    await tokenAlice.transfer(alice, {Substrate: bob.address});
+    await tokenBob.transfer(bob, {Substrate: alice.address});
+    expect(await tokenAlice.getOwner()).to.deep.eq({Substrate: bob.address});
+    expect(await tokenBob.getOwner()).to.deep.eq({Substrate: alice.address});
+  });
+
+  itSub('zero burnFrom NFT', async ({helper}) => {
+    const collection = await helper.nft.mintCollection(alice, {name: 'Zero', description: 'Zero transfer', tokenPrefix: 'TF'});
+    const notApprovedNft = await collection.mintToken(alice, {Substrate: bob.address});
+    const approvedNft = await collection.mintToken(alice, {Substrate: bob.address});
+    await approvedNft.approve(bob, {Substrate: alice.address});
+
+    // 1. Zero burnFrom of non-existing tokens not allowed:
+    await expect(helper.executeExtrinsic(alice, 'api.tx.unique.burnFrom', [collection.collectionId, {Substrate: bob.address}, 9999, 0])).to.be.rejectedWith('common.ApprovedValueTooLow');
+    // 2. Zero burnFrom of not approved tokens not allowed:
+    await expect(helper.executeExtrinsic(alice, 'api.tx.unique.burnFrom', [collection.collectionId, {Substrate: bob.address}, notApprovedNft.tokenId, 0])).to.be.rejectedWith('common.ApprovedValueTooLow');
+    // 3. Zero burnFrom of approved tokens allowed:
+    await helper.executeExtrinsic(alice, 'api.tx.unique.burnFrom', [collection.collectionId, {Substrate: bob.address}, approvedNft.tokenId, 0]);
+
+    // 4.1 approvedNft still approved:
+    expect(await approvedNft.isApproved({Substrate: alice.address})).to.be.true;
+    // 4.2 bob is still the owner:
+    expect(await approvedNft.getOwner()).to.deep.eq({Substrate: bob.address});
+    expect(await notApprovedNft.getOwner()).to.deep.eq({Substrate: bob.address});
+    // 4.3 Alice can burn approved nft:
+    await approvedNft.burnFrom(alice, {Substrate: bob.address});
+    expect(await approvedNft.doesExist()).to.be.false;
+  });
 });

--- a/tests/src/eth/fungible.test.ts
+++ b/tests/src/eth/fungible.test.ts
@@ -277,7 +277,7 @@
     }
   });
 
-  itEth('Cannot transferCross() more than have', async ({helper}) => {
+  ['transfer', 'transferCross'].map(testCase => itEth(`Cannot ${testCase} incorrect amount`, async ({helper}) => {
     const sender = await helper.eth.createAccountWithBalance(donor);
     const receiverEth = await helper.eth.createAccountWithBalance(donor);
     const receiverCrossEth = helper.ethCrossAccount.fromAddress(receiverEth);
@@ -289,8 +289,13 @@
     const collectionAddress = helper.ethAddress.fromCollectionId(collection.collectionId);
     const collectionEvm = helper.ethNativeContract.collection(collectionAddress, 'ft', sender);
 
-    await expect(collectionEvm.methods.transferCross(receiverCrossEth, BALANCE_TO_TRANSFER).send({from: sender})).to.be.rejected;
-  });
+    // 1. Cannot transfer more than have
+    const receiver = testCase === 'transfer' ? receiverEth : receiverCrossEth;
+    await expect(collectionEvm.methods[testCase](receiver, BALANCE_TO_TRANSFER).send({from: sender})).to.be.rejected;
+    // 2. Zero transfer allowed (EIP-20):
+    await collectionEvm.methods[testCase](receiver, 0n).send({from: sender});
+  }));
+  
   
   itEth('Can perform transfer()', async ({helper}) => {
     const owner = await helper.eth.createAccountWithBalance(donor);

--- a/tests/src/eth/nonFungible.test.ts
+++ b/tests/src/eth/nonFungible.test.ts
@@ -517,6 +517,26 @@
       expect(receiverBalance).to.contain(tokenId);
     }
   });
+
+  ['transfer', 'transferCross'].map(testCase => itEth(`Cannot ${testCase} non-owned token`, async ({helper}) => {
+    const sender = await helper.eth.createAccountWithBalance(donor);
+    const tokenOwner = await helper.eth.createAccountWithBalance(donor);
+    const receiverSub = minter;
+    const receiverCrossSub = helper.ethCrossAccount.fromKeyringPair(minter);
+
+    const collection = await helper.nft.mintCollection(minter, {});
+    const collectionAddress = helper.ethAddress.fromCollectionId(collection.collectionId);
+    const collectionEvm = helper.ethNativeContract.collection(collectionAddress, 'nft', sender);
+
+    await collection.mintToken(minter, {Ethereum: sender});
+    const nonSendersToken = await collection.mintToken(minter, {Ethereum: tokenOwner});
+
+    // Cannot transferCross someone else's token:
+    const receiver = testCase === 'transfer' ? helper.address.substrateToEth(receiverSub.address) : receiverCrossSub;
+    await expect(collectionEvm.methods[testCase](receiver, nonSendersToken.tokenId).send({from: sender})).to.be.rejected;
+    // Cannot transfer token if it does not exist:
+    await expect(collectionEvm.methods[testCase](receiver, 999999).send({from: sender})).to.be.rejected;
+  }));
 });
 
 describe('NFT: Fees', () => {

--- a/tests/src/eth/reFungible.test.ts
+++ b/tests/src/eth/reFungible.test.ts
@@ -413,9 +413,10 @@
     }
   });
 
-  itEth.skip('Cannot transferCross with invalid params', async ({helper}) => {
+  ['transfer', 'transferCross'].map(testCase => itEth(`Cannot ${testCase} non-owned token`, async ({helper}) => {
     const sender = await helper.eth.createAccountWithBalance(donor);
     const tokenOwner = await helper.eth.createAccountWithBalance(donor);
+    const receiverSub = minter;
     const receiverCrossSub = helper.ethCrossAccount.fromKeyringPair(minter);
 
     const collection = await helper.rft.mintCollection(minter, {});
@@ -423,12 +424,14 @@
     const collectionEvm = helper.ethNativeContract.collection(collectionAddress, 'rft', sender);
 
     await collection.mintToken(minter, 50n, {Ethereum: sender});
-    const notSendersToken = await collection.mintToken(minter, 50n, {Ethereum: tokenOwner});
+    const nonSendersToken = await collection.mintToken(minter, 50n, {Ethereum: tokenOwner});
+
     // Cannot transferCross someone else's token:
-    await expect(collectionEvm.methods.transferCross(receiverCrossSub, notSendersToken.tokenId).send({from: sender})).to.be.rejected;
-    // FIXME: (transaction successful): Cannot transfer token if it does not exist:
-    await expect(collectionEvm.methods.transferCross(receiverCrossSub, 999999).send({from: sender})).to.be.rejected;
-  });
+    const receiver = testCase === 'transfer' ? helper.address.substrateToEth(receiverSub.address) : receiverCrossSub;
+    await expect(collectionEvm.methods[testCase](receiver, nonSendersToken.tokenId).send({from: sender})).to.be.rejected;
+    // Cannot transfer token if it does not exist:
+    await expect(collectionEvm.methods[testCase](receiver, 999999).send({from: sender})).to.be.rejected;
+  }));
 
   itEth('transfer event on transfer from partial ownership to full ownership', async ({helper}) => {
     const caller = await helper.eth.createAccountWithBalance(donor);

--- a/tests/src/eth/reFungibleToken.test.ts
+++ b/tests/src/eth/reFungibleToken.test.ts
@@ -227,6 +227,46 @@
     }
   });
 
+  [
+    'transfer',
+    // 'transferCross', // TODO
+  ].map(testCase => 
+    itEth(`Cannot ${testCase}() non-owned token`, async ({helper}) => {
+      const owner = await helper.eth.createAccountWithBalance(donor);
+      const receiver = await helper.eth.createAccountWithBalance(donor);
+      const collection = await helper.rft.mintCollection(alice);
+      const rftOwner = await collection.mintToken(alice, 10n, {Ethereum: owner});
+      const rftReceiver = await collection.mintToken(alice, 10n, {Ethereum: receiver});
+      const tokenIdNonExist = 9999999;
+  
+      const tokenAddress1 = helper.ethAddress.fromTokenId(collection.collectionId, rftOwner.tokenId);
+      const tokenAddress2 = helper.ethAddress.fromTokenId(collection.collectionId, rftReceiver.tokenId);
+      const tokenAddressNonExist = helper.ethAddress.fromTokenId(collection.collectionId, tokenIdNonExist);
+      const tokenEvmOwner = helper.ethNativeContract.rftToken(tokenAddress1, owner);
+      const tokenEvmReceiver = helper.ethNativeContract.rftToken(tokenAddress2, owner);
+      const tokenEvmNonExist = helper.ethNativeContract.rftToken(tokenAddressNonExist, owner);
+      
+      // 1. Can transfer zero amount (EIP-20):
+      await tokenEvmOwner.methods[testCase](receiver, 0).send({from: owner});
+      // 2. Cannot transfer non-owned token:
+      await expect(tokenEvmReceiver.methods[testCase](owner, 0).send({from: owner})).to.be.rejected;
+      await expect(tokenEvmReceiver.methods[testCase](owner, 5).send({from: owner})).to.be.rejected;
+      // 3. Cannot transfer non-existing token:
+      await expect(tokenEvmNonExist.methods[testCase](owner, 0).send({from: owner})).to.be.rejected;
+      await expect(tokenEvmNonExist.methods[testCase](owner, 5).send({from: owner})).to.be.rejected;
+
+      // 4. Storage is not corrupted:
+      expect(await rftOwner.getTop10Owners()).to.deep.eq([{Ethereum: owner.toLowerCase()}]);
+      expect(await rftReceiver.getTop10Owners()).to.deep.eq([{Ethereum: receiver.toLowerCase()}]);
+      expect(await helper.rft.getTokenTop10Owners(collection.collectionId, tokenIdNonExist)).to.deep.eq([]); // TODO
+
+      // 4.1 Tokens can be transferred:
+      await tokenEvmOwner.methods[testCase](receiver, 10).send({from: owner});
+      await tokenEvmReceiver.methods[testCase](owner, 10).send({from: receiver});
+      expect(await rftOwner.getTop10Owners()).to.deep.eq([{Ethereum: receiver.toLowerCase()}]);
+      expect(await rftReceiver.getTop10Owners()).to.deep.eq([{Ethereum: owner.toLowerCase()}]);
+    }));
+
   itEth('Can perform repartition()', async ({helper}) => {
     const owner = await helper.eth.createAccountWithBalance(donor);
     const receiver = await helper.eth.createAccountWithBalance(donor);

--- a/tests/src/fungible.test.ts
+++ b/tests/src/fungible.test.ts
@@ -15,7 +15,7 @@
 // along with Unique Network. If not, see <http://www.gnu.org/licenses/>.
 
 import {IKeyringPair} from '@polkadot/types/types';
-import {itSub, usingPlaygrounds, expect} from './util';
+import {itSub, usingPlaygrounds, expect, requirePalletsOrSkip, Pallets} from './util';
 
 const U128_MAX = (1n << 128n) - 1n;
 
@@ -145,3 +145,42 @@
     expect(await collection.getBalance(ethAcc)).to.be.equal(10n);
   });
 });
+
+describe('Fungible negative tests', () => {
+  let donor: IKeyringPair;
+  let alice: IKeyringPair;
+  let bob: IKeyringPair;
+  let charlie: IKeyringPair;
+
+  before(async function() {
+    await usingPlaygrounds(async (helper, privateKey) => {
+      requirePalletsOrSkip(this, helper, [Pallets.Fungible]);
+
+      donor = await privateKey({filename: __filename});
+      [alice, bob, charlie] = await helper.arrange.createAccounts([100n, 100n, 100n], donor);
+    });
+  });
+
+  itSub('Cannot transfer incorrect amount of tokens', async ({helper}) => {
+    const collection = await helper.ft.mintCollection(alice, {name: 'test', description: 'test', tokenPrefix: 'test'});
+    const nonExistingCollection = helper.ft.getCollectionObject(99999);
+    await collection.mint(alice, 10n, {Substrate: bob.address});
+
+    // 1. Alice cannot transfer more than 0 tokens if balance low:
+    await expect(collection.transfer(alice, {Substrate: charlie.address}, 1n)).to.be.rejectedWith('common.TokenValueTooLow');
+    await expect(collection.transfer(alice, {Substrate: charlie.address}, 100n)).to.be.rejectedWith('common.TokenValueTooLow');
+    
+    // 2. Alice cannot transfer non-existing token:
+    await expect(nonExistingCollection.transfer(alice, {Substrate: charlie.address}, 0n)).to.be.rejectedWith('common.CollectionNotFound');
+    await expect(nonExistingCollection.transfer(alice, {Substrate: charlie.address}, 1n)).to.be.rejectedWith('common.CollectionNotFound');
+    
+    // 3. Zero transfer allowed (EIP-20):
+    await collection.transfer(bob, {Substrate: charlie.address}, 0n);
+    // 3.1 even if the balance = 0
+    await collection.transfer(alice, {Substrate: charlie.address}, 0n);
+
+    expect(await collection.getBalance({Substrate: alice.address})).to.eq(0n);
+    expect(await collection.getBalance({Substrate: bob.address})).to.eq(10n);
+    expect(await collection.getBalance({Substrate: charlie.address})).to.eq(0n);
+  });
+});

--- a/tests/src/transfer.test.ts
+++ b/tests/src/transfer.test.ts
@@ -122,6 +122,7 @@
     });
   });
 
+
   itSub('[nft] Transfer with not existed collection_id', async ({helper}) => {
     const collectionId = (1 << 32) - 1;
     await expect(helper.nft.transferToken(alice, collectionId, 1, {Substrate: bob.address}))
@@ -191,6 +192,25 @@
       .to.be.rejectedWith(/common\.TokenValueTooLow/);
   });
 
+  itSub('Zero transfer NFT', async ({helper}) => {
+    const collection = await helper.nft.mintCollection(alice, {name: 'Transfer-Neg-3-NFT', description: '', tokenPrefix: 'T'});
+    const tokenAlice = await collection.mintToken(alice, {Substrate: alice.address});
+    const tokenBob = await collection.mintToken(alice, {Substrate: bob.address});
+    // 1. Zero transfer of own tokens allowed:
+    await helper.executeExtrinsic(alice, 'api.tx.unique.transfer', [{Substrate: bob.address}, collection.collectionId, tokenAlice.tokenId, 0]);
+    // 2. Zero transfer of non-owned tokens not allowed:
+    await expect(helper.executeExtrinsic(alice, 'api.tx.unique.transfer', [{Substrate: alice.address}, collection.collectionId, tokenBob.tokenId, 0])).to.be.rejectedWith('common.NoPermission');
+    // 3. Zero transfer of non-existing tokens not allowed:
+    await expect(helper.executeExtrinsic(alice, 'api.tx.unique.transfer', [{Substrate: alice.address}, collection.collectionId, 10, 0])).to.be.rejectedWith('common.TokenNotFound');
+    expect(await tokenAlice.getOwner()).to.deep.eq({Substrate: alice.address});
+    expect(await tokenBob.getOwner()).to.deep.eq({Substrate: bob.address});
+    // 4. Storage is not corrupted:
+    await tokenAlice.transfer(alice, {Substrate: bob.address});
+    await tokenBob.transfer(bob, {Substrate: alice.address});
+    expect(await tokenAlice.getOwner()).to.deep.eq({Substrate: bob.address});
+    expect(await tokenBob.getOwner()).to.deep.eq({Substrate: alice.address});
+  });
+
   itSub('[nft] Transfer with deleted item_id', async ({helper}) => {
     const collection = await helper.nft.mintCollection(alice, {name: 'Transfer-Neg-3-NFT', description: '', tokenPrefix: 'T'});
     const nft = await collection.mintToken(alice);

--- a/tests/src/transferFrom.test.ts
+++ b/tests/src/transferFrom.test.ts
@@ -349,4 +349,27 @@
       {Substrate: charlie.address},
     )).to.be.rejectedWith(/common\.ApprovedValueTooLow/);
   });
+
+  itSub('zero transfer NFT', async ({helper}) => {
+    const collection = await helper.nft.mintCollection(alice, {name: 'Zero', description: 'Zero transfer', tokenPrefix: 'TF'});
+    const notApprovedNft = await collection.mintToken(alice, {Substrate: bob.address});
+    const approvedNft = await collection.mintToken(alice, {Substrate: bob.address});
+    await approvedNft.approve(bob, {Substrate: alice.address});
+
+    // 1. Cannot zero transferFrom (non-existing token)
+    await expect(helper.executeExtrinsic(alice, 'api.tx.unique.transferFrom', [{Substrate: bob.address}, {Substrate: alice.address}, collection.collectionId, 9999, 0])).to.be.rejectedWith('common.ApprovedValueTooLow');
+    // 2. Cannot zero transferFrom (not approved token)
+    await expect(helper.executeExtrinsic(alice, 'api.tx.unique.transferFrom', [{Substrate: bob.address}, {Substrate: alice.address}, collection.collectionId, notApprovedNft.tokenId, 0])).to.be.rejectedWith('common.ApprovedValueTooLow');
+    // 3. Can zero transferFrom (approved token):
+    await helper.executeExtrinsic(alice, 'api.tx.unique.transferFrom', [{Substrate: bob.address}, {Substrate: alice.address}, collection.collectionId, approvedNft.tokenId, 0]);
+
+    // 4.1 approvedNft still approved:
+    expect(await approvedNft.isApproved({Substrate: alice.address})).to.be.true;
+    // 4.2 bob is still the owner:
+    expect(await approvedNft.getOwner()).to.deep.eq({Substrate: bob.address});
+    expect(await notApprovedNft.getOwner()).to.deep.eq({Substrate: bob.address});
+    // 4.3 Alice can transfer approved nft:
+    await approvedNft.transferFrom(alice, {Substrate: bob.address}, {Substrate: alice.address});
+    expect(await approvedNft.getOwner()).to.deep.eq({Substrate: alice.address});
+  });
 });