Problem Definition

Currently, EVMAddress is constructed from a 20 byte array ([UInt8; 20]) which is handled as a different type than a variable length array. This can present difficulty when working with the struct, especially when deserializing an address hex string to an EVMAddress.

Proposed Solution

Implement serialization & deserialization methods in the EVMAddress struct. Consider something like

access(all) struct EVMAddress {
  // ...
  /// Returns the EVM address as a hex string
  access(all) view fun toString(): String
  // ...
}

/// Returns an EVMAddress from the given string or nil if it is not a valid address
access(all) view fun getEVMAddress(from hex: String): EVMAddress?

These are importantly view methods as the values are helpful to include in events and pre- and post-conditions.

Definition of Done

A developer can deserialize an EVMAddress from a string & back

Context

This functionality has impacts for things like running transactions & scripts via CLI. For example, given the simple task of querying an EVM address's balance, a developer would have to create custom serialization (lots of boilerplate, efforts, and error-prone), pass an EVMAddress (not easy to do using CLI), or pass a byte array (not user friendly).