Bug: json.Unmarshal cannot directly parse Transaction interface in SimulateTransactionInput

[haisenCx]

Description

I encountered a bug while running unit tests using starknetGo. The issue occurs when the code
"err = simulateTxIn.UnmarshalJSON(simulateTxnRaw)" attempts to parse the ./tests/trace/simulateInvokeTx.json file.
The error message is the img below:

I think the error message indicates that json.Unmarshal cannot directly parse the Transaction interface in the SimulateTransactionInput struct

Steps to Reproduce

Run the test TestSimulateTransaction

Suggested Fix

To fix this issue, I suggest implementing a custom UnmarshalJSON method for the SimulateTransactionInput struct. This method will handle the parsing of the Transaction interface by determining the specific struct type.

[thiagodeev]

Hi @haisenCx, sorry for the delay. I ran the test here and everything went well. Could you try again?
I see that the error occurs in line 122, but this line doesn't contain any "relevant" code logic. Have you edited the code?

[haisenCx]

Hi @haisenCx, sorry for the delay. I ran the test here and everything went well. Could you try again? I see that the error occurs in line 122, but this line doesn't contain any "relevant" code logic. Have you edited the code?

Hello, @thiagodeev .Yes, I had modified some code before, so the line numbers in my previous screenshot do not match. Please take a look at this new screenshot I provided above. This is the code from the starknetgo project that I re-cloned, and it is still throwing errors.

[haisenCx]

The issue occurs when running tests in the mainnet env.

[thiagodeev]

Sorry @haisenCx, I forgot this test was supposed to run on mainnet 😅.
Since you made a valid suggestion, could you try to adjust it?

[haisenCx]

Sorry @haisenCx, I forgot this test was supposed to run on mainnet 😅. Since you made a valid suggestion, could you try to adjust it?

Yes,My pleasure🤓

[thiagodeev]

Thanks! 😁
A suggestion I can give is to focus on the Transaction type itself, not the entire SimulateTransactionInput.
I took a look and noticed that the spec says the input value should be a BroadcastTx, and this is not happening. I believe we could make something like that to have a generic BroadcastTx type and then make a custom Unmarshal function to it. This could solve this bug.

Feel free to think of other ideas, bonus for simplicity

[haisenCx]

Thanks! 😁 A suggestion I can give is to focus on the Transaction type itself, not the entire SimulateTransactionInput. I took a look and noticed that the spec says the input value should be a BroadcastTx, and this is not happening. I believe we could make something like that to have a generic BroadcastTx type and then make a custom Unmarshal function to it. This could solve this bug.

Feel free to think of other ideas, bonus for simplicity

Okay, I think your suggestion is the right way, we should follow the spec. I'll take another look, and then I'll post my solution here later.

[onlydustapp]

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[haisenCx]

Hello @thiagodeev, do you mean to change the Transaction in SimulateTransactionInput struct to the BroadcastTxn structure? I see that a BroadcastTxn struct has already been defined in the project. Can it be used directly?

[haisenCx]

I tried using the BroadcastTxn that has already been defined in the project directly, and it solved the UnmarshalJSON issue. However, a new problem has arisen: the expected result and the actual result are not equal.