diff --git a/test/concrete/flowBasic/FlowPreviewTest.sol b/test/concrete/flowBasic/FlowPreviewTest.sol
index 1011102e..25fd5466 100644
--- a/test/concrete/flowBasic/FlowPreviewTest.sol
+++ b/test/concrete/flowBasic/FlowPreviewTest.sol
@@ -146,27 +146,20 @@ contract FlowPreviewTest is FlowBasicTest {
         uint256 erc20AmountIn,
         uint256 erc20AmountOut
     ) external {
-        vm.assume(sentinel != erc20AmountIn);
-        vm.assume(sentinel != erc20AmountOut);
-
         vm.label(alice, "alice");
 
         (IFlowV5 flow,) = deployFlow();
         assumeEtchable(alice, address(flow));
 
-        ERC20Transfer[] memory erc20Transfers = new ERC20Transfer[](2);
-        erc20Transfers[0] =
-            ERC20Transfer({token: address(iTokenA), from: address(flow), to: alice, amount: erc20AmountOut});
-        erc20Transfers[1] =
-            ERC20Transfer({token: address(iTokenA), from: alice, to: address(flow), amount: erc20AmountIn});
-
-        FlowTransferV1 memory flowTransfer =
-            FlowTransferV1(erc20Transfers, new ERC721Transfer[](0), new ERC1155Transfer[](0));
-        uint256[] memory stack = generateFlowStack(flowTransfer);
-
-        assertEq(
-            keccak256(abi.encode(flowTransfer)), keccak256(abi.encode(flow.stackToFlow(stack))), "wrong compare Structs"
+        (uint256[] memory stack, bytes32 transferHash) = mintAndBurnFlowStack(
+            alice,
+            20 ether,
+            10 ether,
+            5,
+            createTransfersERC20toERC20(alice, address(flow), erc20AmountIn, erc20AmountOut)
         );
+
+        assertEq(transferHash, keccak256(abi.encode(flow.stackToFlow(stack))), "wrong compare Structs");
     }
 
     /**
diff --git a/test/concrete/flowErc1155/FlowPreviewTest.sol b/test/concrete/flowErc1155/FlowPreviewTest.sol
index 5203b660..80325f54 100644
--- a/test/concrete/flowErc1155/FlowPreviewTest.sol
+++ b/test/concrete/flowErc1155/FlowPreviewTest.sol
@@ -129,6 +129,31 @@ contract FlowPreviewTest is FlowERC1155Test {
         assertEq(transferHash, keccak256(abi.encode(flow.stackToFlow(stack))), "wrong compare Structs");
     }
 
+    /**
+     * @dev Tests the preview of defined Flow IO for ERC20
+     *      using single-element arrays.
+     */
+    function testFlowERC1155PreviewDefinedFlowIOForERC20SingleElementArrays(
+        address alice,
+        uint256 erc20AmountIn,
+        uint256 erc20AmountOut
+    ) external {
+        vm.label(alice, "alice");
+
+        (IFlowERC1155V5 flow,) = deployIFlowERC1155V5("https://www.rainprotocol.xyz/nft/");
+        assumeEtchable(alice, address(flow));
+
+        (uint256[] memory stack, bytes32 transferHash) = mintAndBurnFlowStack(
+            alice,
+            20 ether,
+            10 ether,
+            5,
+            createTransfersERC20toERC20(alice, address(flow), erc20AmountIn, erc20AmountOut)
+        );
+
+        assertEq(transferHash, keccak256(abi.encode(flow.stackToFlow(stack))), "wrong compare Structs");
+    }
+
     /// Should preview empty flow io
     function testFlowERC1155PreviewEmptyFlowIO(string memory uri, address alice, uint256 amount) public {
         (IFlowERC1155V5 flow,) = deployIFlowERC1155V5({uri: uri});
diff --git a/test/concrete/flowErc20/FlowPreviewTest.sol b/test/concrete/flowErc20/FlowPreviewTest.sol
index 801babc5..d1197721 100644
--- a/test/concrete/flowErc20/FlowPreviewTest.sol
+++ b/test/concrete/flowErc20/FlowPreviewTest.sol
@@ -142,41 +142,24 @@ contract FlowPreviewTest is FlowERC20Test {
      */
     /// forge-config: default.fuzz.runs = 100
     function testFlowERC20PreviewDefinedFlowIOForERC20SingleElementArrays(
-        string memory name,
-        string memory symbol,
         address alice,
         uint256 erc20AmountIn,
         uint256 erc20AmountOut
     ) external {
-        vm.assume(sentinel != erc20AmountIn);
-        vm.assume(sentinel != erc20AmountOut);
-
         vm.label(alice, "alice");
 
-        (IFlowERC20V5 flow,) = deployFlowERC20(name, symbol);
+        (IFlowERC20V5 flow,) = deployFlowERC20("Flow ERC20", "F20");
         assumeEtchable(alice, address(flow));
 
-        ERC20Transfer[] memory erc20Transfers = new ERC20Transfer[](2);
-        erc20Transfers[0] =
-            ERC20Transfer({token: address(iTokenA), from: address(flow), to: alice, amount: erc20AmountOut});
-        erc20Transfers[1] =
-            ERC20Transfer({token: address(iTokenA), from: alice, to: address(flow), amount: erc20AmountIn});
-
-        ERC20SupplyChange[] memory mints = new ERC20SupplyChange[](1);
-        mints[0] = ERC20SupplyChange({account: alice, amount: 20 ether});
-
-        ERC20SupplyChange[] memory burns = new ERC20SupplyChange[](1);
-        burns[0] = ERC20SupplyChange({account: alice, amount: 10 ether});
-
-        FlowERC20IOV1 memory flowERC20IO = FlowERC20IOV1(
-            mints, burns, FlowTransferV1(erc20Transfers, new ERC721Transfer[](0), new ERC1155Transfer[](0))
+        (uint256[] memory stack, bytes32 transferHash) = mintAndBurnFlowStack(
+            alice,
+            20 ether,
+            10 ether,
+            5,
+            createTransfersERC20toERC20(alice, address(flow), erc20AmountIn, erc20AmountOut)
         );
 
-        uint256[] memory stack = generateFlowStack(flowERC20IO);
-
-        assertEq(
-            keccak256(abi.encode(flowERC20IO)), keccak256(abi.encode(flow.stackToFlow(stack))), "wrong compare Structs"
-        );
+        assertEq(transferHash, keccak256(abi.encode(flow.stackToFlow(stack))), "wrong compare Structs");
     }
 
     /**
diff --git a/test/concrete/flowErc721/FlowPreviewTest.sol b/test/concrete/flowErc721/FlowPreviewTest.sol
index 7034c65a..7e3b831f 100644
--- a/test/concrete/flowErc721/FlowPreviewTest.sol
+++ b/test/concrete/flowErc721/FlowPreviewTest.sol
@@ -142,42 +142,25 @@ contract FlowPreviewTest is FlowERC721Test {
      */
     /// forge-config: default.fuzz.runs = 100
     function testFlowERC721PreviewDefinedFlowIOForERC20SingleElementArrays(
-        string memory symbol,
-        string memory baseURI,
         address alice,
         uint256 erc20AmountIn,
         uint256 erc20AmountOut
     ) external {
-        vm.assume(sentinel != erc20AmountIn);
-        vm.assume(sentinel != erc20AmountOut);
-
         vm.label(alice, "alice");
 
-        (IFlowERC721V5 flow,) = deployFlowERC721({name: symbol, symbol: symbol, baseURI: baseURI});
+        (IFlowERC721V5 flow,) =
+            deployFlowERC721({name: "FlowErc721", symbol: "FErc721", baseURI: "https://www.rainprotocol.xyz/nft/"});
         assumeEtchable(alice, address(flow));
 
-        ERC20Transfer[] memory erc20Transfers = new ERC20Transfer[](2);
-        erc20Transfers[0] =
-            ERC20Transfer({token: address(iTokenA), from: address(flow), to: alice, amount: erc20AmountOut});
-        erc20Transfers[1] =
-            ERC20Transfer({token: address(iTokenA), from: alice, to: address(flow), amount: erc20AmountIn});
-
-        ERC721SupplyChange[] memory mints = new ERC721SupplyChange[](2);
-        mints[0] = ERC721SupplyChange({account: alice, id: 1});
-        mints[1] = ERC721SupplyChange({account: alice, id: 2});
-
-        ERC721SupplyChange[] memory burns = new ERC721SupplyChange[](1);
-        burns[0] = ERC721SupplyChange({account: alice, id: 2});
-
-        FlowERC721IOV1 memory flowERC721IO = FlowERC721IOV1(
-            mints, burns, FlowTransferV1(erc20Transfers, new ERC721Transfer[](0), new ERC1155Transfer[](0))
+        (uint256[] memory stack, bytes32 transferHash) = mintAndBurnFlowStack(
+            alice,
+            20 ether,
+            10 ether,
+            5,
+            createTransfersERC20toERC20(alice, address(flow), erc20AmountIn, erc20AmountOut)
         );
 
-        uint256[] memory stack = generateFlowStack(flowERC721IO);
-
-        assertEq(
-            keccak256(abi.encode(flowERC721IO)), keccak256(abi.encode(flow.stackToFlow(stack))), "wrong compare Structs"
-        );
+        assertEq(transferHash, keccak256(abi.encode(flow.stackToFlow(stack))), "wrong compare Structs");
     }
 
     /**