Bridge standup script + Flow Port & Migrationnet prep

.gitignore

@@ -25,4 +25,7 @@ coverage.lcov
 *.pem
 
 # Local configs
-local.flow.json
+local.flow.json
+
+# Local
+.DS_Store

README.md

@@ -12,7 +12,7 @@ addresses:
 
 |Contracts|PreviewNet|Testnet|Mainnet|
 |---|---|---|---|
-|All Cadence Bridge contracts|`0x715c57f7a59bc39b`|TBD|TBD|
+|All Cadence Bridge contracts|`0x715c57f7a59bc39b`|`0xdfc20aee650fcbdf`|TBD|
 |[`FlowEVMBridgeFactory.sol`](./solidity/src/FlowBridgeFactory.sol)|`0xf23c8619603434f7f71659820193c8e491feb1d9`|TBD|TBD|
 |[`FlowEVMBridgeDeploymentRegistry.sol`](./solidity/src/FlowEVMBridgeDeploymentRegistry.sol)|`0x544ef4ed9209ebe6989bed9e543632512afb25de`|TBD|TBD|
 |[`FlowEVMBridgedERC20Deployer.sol`](./solidity/src/FlowEVMBridgedERC20Deployer.sol)|`0xc5577d2935ef0556b37358d8b92aa578f1e7564e`|TBD|TBD|
@@ -87,8 +87,8 @@ that moving $FLOW to EVM is built into the `EVMAddress` object so any requests b
 leverage this interface; however, moving $FLOW from EVM to Cadence must be done through the COA resource.
 
 Below are transactions relevant to bridging fungible tokens:
-- [`bridge_tokens_to_evm.cdc`](./cadence/transactions/bridge/ft/bridge_tokens_to_evm.cdc)
-- [`bridge_tokens_from_evm.cdc`](./cadence/transactions/bridge/ft/bridge_tokens_from_evm.cdc)
+- [`bridge_tokens_to_evm.cdc`](./cadence/transactions/bridge/tokens/bridge_tokens_to_evm.cdc)
+- [`bridge_tokens_from_evm.cdc`](./cadence/transactions/bridge/tokens/bridge_tokens_from_evm.cdc)
 
 
 ## Prep Your Assets for Bridging

cadence/contracts/bridge/FlowEVMBridgeUtils.cdc

@@ -1284,6 +1284,6 @@ contract FlowEVMBridgeUtils {
             }
         }
         self.bridgeFactoryEVMAddress = EVMUtils.getEVMAddressFromHexString(address: bridgeFactoryAddressHex.toLower())
-            ?? panic("Invalid EVM address hex")
+            ?? panic("Invalid EVM address hex: ".concat(bridgeFactoryAddressHex))
     }
 }

cadence/contracts/bridge/interfaces/FlowEVMBridgeHandlerInterfaces.cdc

@@ -37,7 +37,7 @@ access(all) contract FlowEVMBridgeHandlerInterfaces {
     ///
     access(all) resource interface HandlerInfo {
         /// Returns whether the Handler is enabled
-        access(all)	view fun isEnabled(): Bool
+        access(all) view fun isEnabled(): Bool
         /// Returns the Cadence type handled by the Handler, nil if not set
         access(all) view fun getTargetType(): Type?
         /// Returns the EVM address handled by the Handler, nil if not set

cadence/contracts/utils/EVMUtils.cdc

@@ -12,17 +12,7 @@ access(all) contract EVMUtils {
     // TODO: Remove once EVMAddress.toString() is available
     access(all)
     view fun getEVMAddressAsHexString(address: EVM.EVMAddress): String {
-        let bytes = address.bytes
-        // Iterating & appending to an array is not allowed in a `view` method and this method must be `view` for
-        // certain use cases in the bridge contracts - namely for emitting values in pre- & post-conditions
-        let addressBytes: [UInt8] = [
-            bytes[0], bytes[1], bytes[2], bytes[3],
-            bytes[4], bytes[5], bytes[6], bytes[7],
-            bytes[8], bytes[9], bytes[10], bytes[11],
-            bytes[12], bytes[13], bytes[14], bytes[15],
-            bytes[16], bytes[17], bytes[18], bytes[19]
-        ]
-        return String.encodeHex(addressBytes)
+        return String.encodeHex(address.bytes.toVariableSized())
     }
 
     /// Returns an EVMAddress as a hex string without a 0x prefix, truncating the string's last 20 bytes if exceeded
@@ -33,19 +23,12 @@ access(all) contract EVMUtils {
     ///
     access(all)
     fun getEVMAddressFromHexString(address: String): EVM.EVMAddress? {
-        if address.length != 40 {
-            return nil
+        pre {
+            address.length == 40 || address.length == 42: "Invalid hex string length"
         }
-        var addressBytes: [UInt8] = address.toLower().decodeHex()
-        if addressBytes.length != 20 {
-            return nil
-        }
-        return EVM.EVMAddress(bytes: [
-            addressBytes[0], addressBytes[1], addressBytes[2], addressBytes[3],
-            addressBytes[4], addressBytes[5], addressBytes[6], addressBytes[7],
-            addressBytes[8], addressBytes[9], addressBytes[10], addressBytes[11],
-            addressBytes[12], addressBytes[13], addressBytes[14], addressBytes[15],
-            addressBytes[16], addressBytes[17], addressBytes[18], addressBytes[19]
-        ])
+        // Strip the 0x prefix if it exists
+        var withoutPrefix = (address[1] == "x" ? address.slice(from: 2, upTo: address.length) : address).toLower()
+        let bytes = withoutPrefix.decodeHex().toConstantSized<[UInt8;20]>()!
+        return EVM.EVMAddress(bytes: bytes)
     }
 }

cadence/transactions/bridge/onboarding/batch_onboard_by_evm_address.cdc

@@ -9,7 +9,8 @@ import "EVMUtils"
 import "FlowEVMBridge"
 import "FlowEVMBridgeConfig"
 
-/// This transaction onboards the NFT type to the bridge, configuring the bridge to move NFTs between environments
+/// This transaction onboards ERC20/ERC721 assets to the bridge, configuring the bridge to move assets between
+/// environments
 /// NOTE: This must be done before bridging a Cadence-native NFT to EVM
 ///
 /// @param addressesAsHex: Array of EVM contract addresses (as hex string without 0x prefix) defining the 

cadence/transactions/bridge/onboarding/batch_onboard_by_type.cdc

@@ -8,7 +8,8 @@ import "EVM"
 import "FlowEVMBridge"
 import "FlowEVMBridgeConfig"
 
-/// This transaction onboards the asset type to the bridge, configuring the bridge to move assets between environments
+/// This transaction onboards ERC20/ERC721 assets to the bridge, configuring the bridge to move assets between
+/// environments
 /// NOTE: This must be done before bridging a Cadence-native asset to EVM
 ///
 /// @param types: The Cadence types of the bridgeable asset to onboard to the bridge

cadence/transactions/example-assets/evm-assets/safe_transfer_from_erc721.cdc

@@ -0,0 +1,53 @@
+import "EVM"
+
+import "EVMUtils"
+import "FlowEVMBridgeUtils"
+
+/// Executes an NFT transfer to the defined recipient address against the specified ERC721 contract.
+///
+transaction(evmContractAddressHex: String, recipientAddressHex: String, id: UInt256) {
+
+    let evmContractAddress: EVM.EVMAddress
+    let recipientAddress: EVM.EVMAddress
+    let coa: auth(EVM.Call) &EVM.CadenceOwnedAccount
+    var senderOwnerCheck: Bool
+    var recipientOwnerCheck: Bool
+
+    prepare(signer: auth(BorrowValue) &Account) {
+        self.evmContractAddress = EVMUtils.getEVMAddressFromHexString(address: evmContractAddressHex) ?? panic("Invalid contract address")
+        self.recipientAddress = EVMUtils.getEVMAddressFromHexString(address: recipientAddressHex) ?? panic("Invalid recipient address")
+
+        self.coa = signer.storage.borrow<auth(EVM.Call) &EVM.CadenceOwnedAccount>(from: /storage/evm)
+            ?? panic("Could not borrow CadenceOwnedAccount reference")
+
+        self.senderOwnerCheck = FlowEVMBridgeUtils.isOwnerOrApproved(
+                ofNFT: id,
+                owner: self.coa.address(),
+                evmContractAddress: self.evmContractAddress
+            )
+        self.recipientOwnerCheck = false
+    }
+
+    execute {
+        let calldata = EVM.encodeABIWithSignature(
+                "safeTransferFrom(address,address,uint256)",
+                [self.coa.address(), self.recipientAddress, id]
+            )
+        let callResult = self.coa.call(
+            to: self.evmContractAddress,
+            data: calldata,
+            gasLimit: 15_000_000,
+            value: EVM.Balance(attoflow: 0)
+        )
+        assert(callResult.status == EVM.Status.successful, message: "Call to ERC721 contract failed")
+        self.recipientOwnerCheck = FlowEVMBridgeUtils.isOwnerOrApproved(
+                ofNFT: id,
+                owner: self.recipientAddress,
+                evmContractAddress: self.evmContractAddress
+            )
+    }
+
+    post {
+        self.recipientOwnerCheck: "Recipient did not receive the token"
+    }
+}

cadence/transactions/example-assets/evm-assets/transfer_erc20.cdc

@@ -0,0 +1,42 @@
+import "EVM"
+
+import "EVMUtils"
+import "FlowEVMBridgeUtils"
+
+/// Executes a token transfer to the defined recipient address against the specified ERC20 contract.
+///
+transaction(evmContractAddressHex: String, recipientAddressHex: String, amount: UInt256) {
+
+    let evmContractAddress: EVM.EVMAddress
+    let recipientAddress: EVM.EVMAddress
+    let coa: auth(EVM.Call) &EVM.CadenceOwnedAccount
+    let preBalance: UInt256
+    var postBalance: UInt256
+
+    prepare(signer: auth(BorrowValue) &Account) {
+        self.evmContractAddress = EVMUtils.getEVMAddressFromHexString(address: evmContractAddressHex) ?? panic("Invalid contract address")
+        self.recipientAddress = EVMUtils.getEVMAddressFromHexString(address: recipientAddressHex) ?? panic("Invalid recipient address")
+
+        self.coa = signer.storage.borrow<auth(EVM.Call) &EVM.CadenceOwnedAccount>(from: /storage/evm)
+            ?? panic("Could not borrow CadenceOwnedAccount reference")
+
+        self.preBalance = FlowEVMBridgeUtils.balanceOf(owner: self.coa.address(), evmContractAddress: self.evmContractAddress)
+        self.postBalance = 0
+    }
+
+    execute {
+        let calldata = EVM.encodeABIWithSignature("transfer(address,uint256)", [self.recipientAddress, amount])
+        let callResult = self.coa.call(
+            to: self.evmContractAddress,
+            data: calldata,
+            gasLimit: 15_000_000,
+            value: EVM.Balance(attoflow: 0)
+        )
+        assert(callResult.status == EVM.Status.successful, message: "Call to ERC20 contract failed")
+        self.postBalance = FlowEVMBridgeUtils.balanceOf(owner: self.coa.address(), evmContractAddress: self.evmContractAddress)
+    }
+
+    post {
+        self.postBalance == self.preBalance - amount: "Transfer failed"
+    }
+}

cadence/transactions/flow-token/dynamic_vm_transfer.cdc

@@ -0,0 +1,106 @@
+import "FungibleToken"
+import "FlowToken"
+
+import "EVM"
+
+import "EVMUtils"
+
+// Transfers $FLOW from the signer's account to the recipient's address, determining the target VM based on the format
+// of the recipient's hex address. Note that the sender's funds are sourced by default from the target VM, pulling any
+// difference from the alternate VM if available. e.g. Transfers to Flow addresses will first attempt to withdraw from
+// the signer's Flow vault, pulling any remaining funds from the signer's EVM account if available. Transfers to EVM
+// addresses will first attempt to withdraw from the signer's EVM account, pulling any remaining funds from the signer's
+// Flow vault if available. If the signer's balance across both VMs is insufficient, the transaction will revert.
+///
+/// @param addressString: The recipient's address in hex format - this should be either an EVM address or a Flow address
+/// @param amount: The amount of $FLOW to transfer as a UFix64 value
+///
+transaction(addressString: String, amount: UFix64) {
+
+    let sentVault: @FlowToken.Vault
+    let evmRecipient: EVM.EVMAddress?
+    var receiver: &{FungibleToken.Receiver}?
+
+    prepare(signer: auth(BorrowValue, SaveValue) &Account) {
+        // Reference signer's COA if one exists
+        let coa = signer.storage.borrow<auth(EVM.Withdraw) &EVM.CadenceOwnedAccount>(from: /storage/evm)
+
+        // Reference signer's FlowToken Vault
+        let sourceVault = signer.storage.borrow<auth(FungibleToken.Withdraw) &FlowToken.Vault>(from: /storage/flowTokenVault)
+            ?? panic("Could not borrow signer's FlowToken.Vault")
+        let cadenceBalance = sourceVault.balance
+
+        // Define optional recipients for both VMs
+        self.receiver = nil
+        let cadenceRecipient = Address.fromString(addressString)
+        self.evmRecipient = cadenceRecipient == nil ? EVMUtils.getEVMAddressFromHexString(address: addressString) : nil
+        // Validate exactly one target address is assigned
+        if cadenceRecipient != nil && self.evmRecipient != nil {
+            panic("Malformed recipient address - assignable as both Cadence and EVM addresses")
+        } else if cadenceRecipient == nil && self.evmRecipient == nil {
+            panic("Malformed recipient address - not assignable as either Cadence or EVM address")
+        }
+
+        // Create empty FLOW vault to capture funds
+        self.sentVault <- FlowToken.createEmptyVault(vaultType: Type<@FlowToken.Vault>())
+        /// If the target VM is Flow, does the Vault have sufficient balance to cover?
+        if cadenceRecipient != nil {
+            // Assign the Receiver of the $FLOW transfer
+            self.receiver = getAccount(cadenceRecipient!).capabilities.borrow<&{FungibleToken.Receiver}>(
+                    /public/flowTokenReceiver
+                ) ?? panic("Could not borrow reference to recipient's FungibleToken.Receiver")
+
+            // Withdraw from the signer's Cadence Vault and deposit to sentVault
+            var withdrawAmount = amount < cadenceBalance ? amount : cadenceBalance
+            self.sentVault.deposit(from: <-sourceVault.withdraw(amount: withdrawAmount))
+
+            // If the cadence balance didn't cover the amount, check the signer's EVM balance
+            if amount > self.sentVault.balance {
+                let difference = amount - cadenceBalance
+                // Revert if the signer doesn't have an EVM account or EVM balance is insufficient
+                if coa == nil || difference < coa!.balance().inFLOW() {
+                    panic("Insufficient balance across Flow and EVM accounts")
+                }
+
+                // Withdraw from the signer's EVM account and deposit to sentVault
+                let withdrawFromEVM = EVM.Balance(attoflow: 0)
+                withdrawFromEVM.setFLOW(flow: difference)
+                self.sentVault.deposit(from: <-coa!.withdraw(balance: withdrawFromEVM))
+            }
+        } else if self.evmRecipient != nil {
+            // Check signer's balance can cover the amount
+            if coa != nil {
+                // Determine the amount to withdraw from the signer's EVM account
+                let balance = coa!.balance()
+                let withdrawAmount = amount < balance.inFLOW() ? amount : balance.inFLOW()
+                balance.setFLOW(flow: withdrawAmount)
+
+                // Withdraw funds from EVM to the sentVault
+                self.sentVault.deposit(from: <-coa!.withdraw(balance: balance))
+            }
+            if amount > self.sentVault.balance {
+                // Insufficient amount withdrawn from EVM, check signer's Flow balance
+                let difference = amount - self.sentVault.balance
+                if difference > cadenceBalance {
+                    panic("Insufficient balance across Flow and EVM accounts")
+                }
+                // Withdraw from the signer's Cadence Vault and deposit to sentVault
+                self.sentVault.deposit(from: <-sourceVault.withdraw(amount: difference))
+            }
+        }
+    }
+
+    pre {
+        self.sentVault.balance == amount: "Attempting to send an incorrect amount of $FLOW"
+    }
+
+    execute {
+        // Complete Cadence transfer if the FungibleToken Receiver is assigned
+        if self.receiver != nil {
+            self.receiver!.deposit(from: <-self.sentVault)
+        } else {
+            // Otherwise, complete EVM transfer
+            self.evmRecipient!.deposit(from: <-self.sentVault)
+        }
+    }
+}