feat: support ethabi Contract methods

[andyrobert3]

Motivation

Fixes #101

Struggling to write tests for load method from ethabi
Thanks @prestwich for the help!

Solution

Reference from methods from ethabi

PR Checklist

• Added Tests
• Added Documentation
• Breaking changes

[andyrobert3]

@prestwich @DaniPopes

When writing tests for .load() i face this issue

value: Error("invalid type: string "address", expected a valid internal type", line: 1, column: 250)'

I used the same implementation as ethabi
https://docs.rs/ethabi/latest/src/ethabi/contract.rs.html#167-169

let file_path: String = format!("tests/{}", path);
let file: File = File::open(file_path).unwrap();
let buffer: BufReader<File> = BufReader::new(file);
let loaded_abi: JsonAbi = JsonAbi::load(buffer).unwrap();

Do you know how to solve this?
Why does include_str! work with string parsing but not run time File::open with BufReader

Tried adding Basic(String) into InternalType, to no avail

pub enum InternalType {
    // ... 
    Basic(String),
}

[prestwich]

value: Error("invalid type: string "address", expected a valid internal type", line: 1, column: 250)'

this seems odd. can you link to the ABI file that you're using for tests?

nevermind i am dumb it's in the folder already

[prestwich]

okay i have tracked this down.

• InternalType is deserialized by borrowing data from the deserializer with Visitor::visit_borrowed_str
• serde_json::from_reader configures the Deserializer to not call Visitor::visit_borrowed_str (why?)
• Instead it calls Visitor::visit_string which implicitly calls Visitor::visit_str.
• Neither of those are implemented for the ItVisitor.
• Because the deserializer calls an unimplement vist_ method, it returns the unexpected error, even tho the input is actually expected

[prestwich]

@andyrobert3 if you don't mind, I can push a fix to your branch. the fix will be loading the entire file into a string and then chaning to read_string, as well as making serde_json::from_reader always error with a clear message

[andyrobert3]

sure @prestwich feel free to push!

need to sleep since its a bit late here

[prestwich]

cool i pushed. this solves the immediate issue, and should make it clearer for future users :)

[DaniPopes]

Rest LGTM

[prestwich]

needs cargo fmt

[prestwich]

@DaniPopes mind re-reviewing with my additions? :)

[andyrobert3]

Was going to work on the requested changes today, but thanks to @prestwich @DaniPopes for reviewing and making the required changes

[prestwich]

yeah, hope you don't mind us getting it over the finish line. thank you for your contribution! 🎉