check if bridge address has code before preparing tx payload

[tclemos]

closes https://github.com/0xPolygon/devtools/issues/184

[Copilot]

Pull Request Overview

The PR adds a check to ensure that the bridge address contains deployed code before preparing the transaction payload.

• Adds a new helper function "hasCode" to validate the bridge address.
• Integrates the "hasCode" check within "generateTransactionPayload" to return an error early if the bridge address is not valid.

Comments suppressed due to low confidence (1)

cmd/ulxly/ulxly.go:1118

• Consider using a passed-in context (e.g., from generateTransactionPayload) instead of context.Background() to ensure consistent cancellation and timeout handling.

code, err := client.CodeAt(context.Background(), common.HexToAddress(address), nil)

[Copilot]

Pull Request Overview

This PR adds a safeguard to ensure that the bridge address has deployed code before preparing a transaction payload, addressing issue #184.

• Introduced the hasCode function to check for contract code at a given address.
• Integrated the hasCode check into generateTransactionPayload to prevent constructing a transaction with an invalid bridge address.

[Copilot]

Pull Request Overview

This PR adds a check to determine whether the provided bridge address actually contains deployed contract code before preparing the transaction payload.

• Added the hasCode function which retrieves the bytecode at the provided address and returns an error if no code is detected.
• Updated generateTransactionPayload to wrap and return an error if the bridge address has no contract code.

[Copilot]

Pull Request Overview

This PR ensures that the bridge address has on-chain code before preparing the transaction payload, mitigating potential issues with invalid addresses.

• Added a helper function, hasCode, to check the existence of code at a given address.
• Updated generateTransactionPayload to invoke hasCode and return an error if the bridge address lacks code.

Comments suppressed due to low confidence (1)

cmd/ulxly/ulxly.go:1117

• [nitpick] Consider renaming 'hasCode' to something more descriptive like 'ensureCodePresent' to clarify that the function returns an error if no code is found.

func hasCode(ctx context.Context, client *ethclient.Client, address string) error {

[Copilot]

Pull Request Overview

This PR adds a pre-check to verify that the bridge address contains deployed code before preparing the transaction payload, addressing issue #184.

• Added a helper function, ensureCodePresent, to check for code at a given address.
• Integrated ensureCodePresent into generateTransactionPayload to prevent sending transactions to non-code addresses.

Comments suppressed due to low confidence (1)

cmd/ulxly/ulxly.go:1117

• [nitpick] Consider adding unit tests to cover the ensureCodePresent function to verify its behavior when the code is absent at a given address.

func ensureCodePresent(ctx context.Context, client *ethclient.Client, address string) error {

[leovct]

lgtm, left a small comment