Add Celo support (#8)

* feat(types): add optional Celo support

* feat: add Celo feature flags to all crates

* test(provider): add get_transaction celo test

* test(signer): add send_transaction celo test

* test(contract): add deploy and call contract function celo test

Author: gakonst

Diff for: .github/workflows/ci.yml

@@ -42,6 +42,11 @@ jobs:
             export PATH=$HOME/bin:$PATH
             cargo test
 
+      - name: cargo test (Celo)
+        run: |
+            export PATH=$HOME/bin:$PATH
+            cargo test --all-features
+
       - name: cargo fmt
         run: cargo fmt --all -- --check
 

Diff for: Cargo.lock

@@ -1,6 +1,6 @@
 # <h1 align="center"> ethers.rs </h1>
 
-**Complete Ethereum wallet implementation and utilities in Rust**
+**Complete Ethereum and Celo wallet implementation and utilities in Rust**
 
 [![CircleCI](https://circleci.com/gh/circleci/circleci-docs.svg?style=svg)](https://circleci.com/gh/circleci/circleci-docs)
 
@@ -20,6 +20,24 @@ ethers = { git = "github.com/gakonst/ethers-rs" }
 
 </details>
 
+### Celo Support
+
+[Celo](http://celo.org/) support is turned on via the feature-flag `celo`:
+
+```toml
+[dependencies]
+
+ethers = { git = "github.com/gakonst/ethers-rs", features = ["celo"] }
+```
+
+Celo's transactions differ from Ethereum transactions by including 3 new fields:
+- `fee_currency`: The currency fees are paid in (None for CELO, otherwise it's an Address)
+- `gateway_fee_recipient`: The address of the fee recipient (None for no gateway fee paid)
+- `gateway_fee`: Gateway fee amount (None for no gateway fee paid)
+
+The feature flag enables these additional fields in the transaction request builders and
+in the transactions which are fetched over JSON-RPC.
+
 ## Features
 
 - [x] Ethereum JSON-RPC Client
@@ -28,6 +46,7 @@ ethers = { git = "github.com/gakonst/ethers-rs" }
 - [x] Querying past events
 - [x] Event monitoring as `Stream`s
 - [x] ENS as a first class citizen
+- [x] Celo support
 - [ ] Websockets / `eth_subscribe`
 - [ ] Hardware Wallet Support
 - [ ] WASM Bindings

Diff for: README.md

@@ -19,8 +19,11 @@ once_cell = { version = "1.3.1", default-features = false }
 futures = "0.3.5"
 
 [dev-dependencies]
+ethers = { version = "0.1.0", path = "../ethers" }
 tokio = { version = "0.2.21", default-features = false, features = ["macros"] }
 serde_json = "1.0.55"
+serial_test = "0.4.0"
 
 [features]
 abigen = ["ethers-contract-abigen", "ethers-contract-derive"]
+celo = ["ethers-core/celo", "ethers-core/celo", "ethers-providers/celo", "ethers-signers/celo"]

Diff for: ethers-contract/Cargo.toml

@@ -10,9 +10,10 @@ use ethers_signers::{Client, Signer};
 #[derive(Debug, Clone)]
 /// Helper which manages the deployment transaction of a smart contract
 pub struct Deployer<'a, P, S> {
+    /// The deployer's transaction, exposed for overriding the defaults
+    pub tx: TransactionRequest,
     abi: Abi,
     client: &'a Client<P, S>,
-    tx: TransactionRequest,
     confs: usize,
 }