Accepted - The PR has been merged in #2108
- 2022-04-19: Initial Proposal
There is a lot of common methods in the ChainHandle and ChainEndpoint traits, sometimes with minute differences between one another. This document provides a way to remove the duplication of methods for increased maintainability of the codebase, along with a few suggestions to standardize the method signatures.
There are currently discrepancies between how methods take their arguments. Some take a request object, and others take fine-grained arguments that will be used to build a request object in the implementation of the method. For example, query_consensus_state() takes arguments that will be used to build a request object, whereas query_consensus_states() takes a request object directly.
fn query_consensus_state(
&self,
client_id: ClientId,
consensus_height: Height,
query_height: Height,
) -> ...;
fn query_consensus_states(
&self,
request: QueryConsensusStatesRequest,
) -> ...;All methods will be refactored to take a request object as argument.
Currently, the type for the request objects is the "raw type", coming from the compiled protobuf files. For each such type, we will create a corresponding domain type, following a similar pattern as elsewhere in the codebase.
This will allow us to modify the domain type as we wish, without requiring a change in the protobuf file (and thus, requiring a change in the communication protocol). A first such change of the domain type we foresee would alter the type to specify a height in queries; however this is out of scope for this particular ADR.
- The protobuf types are not exposed directly, which allows
hermesto work with future non-tendermint chains - Increased readability of the codebase; similar methods have a similar format
- Option type should be used with non-zero Height #1009
- The new domain types proposed here, as well as the reduced deduplication of methods, will make fixing this issue easier