Add EIP-1193 support (#414)

* Put signing behind an optional feature

libsecp256k1 doesn't compile with the WASM target, and you don't need to sign
transactions or messages in the browser anyway, since your wallet usually
manages the keys.

* Add EIP-1193 support

* Add eth_requestAccounts method

* 'cargo check' EIP-1193 code in Travis

* Clean up the feature gates a little

* Style cleanup in eip_1193.rs

* remove meaningless #[wasm_bindgen] attribute

* Refactor translating events from JS

* Replace some Error::Internals with panics with useful messages

* rename get_default -> default

* Refactor error handling in request_wrapped

* clean up EIP-1193 listeners on Drop

* Add support for more EIP-1193 events

* Reduce the number of #[cfg(feature = "signing")] attributes a bit more

.travis.yml

@@ -33,6 +33,7 @@ before_script:
   - if [[ "${TRAVIS_RUST_VERSION}" == stable ]]; then
       rustup component add rustfmt && cargo install cargo-deny;
     fi
+  - rustup target add wasm32-unknown-unknown
 
 script:
   - if [[ "${TRAVIS_RUST_VERSION}" == "stable" ]]; then
@@ -42,6 +43,7 @@ script:
   - cargo build
   - cargo test
   - cargo check --no-default-features
+  - cargo check --target wasm32-unknown-unknown --no-default-features --features eip-1193
   - cargo check --no-default-features --features http
   - cargo check --no-default-features --features http-tls
   - cargo check --no-default-features --features ws-tokio

Cargo.toml

@@ -23,7 +23,7 @@ log = "0.4.6"
 parking_lot = "0.11.0"
 rlp = "0.4"
 rustc-hex = "2.1.0"
-secp256k1 = { version = "0.19", features = ["recovery"] }
+secp256k1 = { version = "0.19", features = ["recovery"], optional = true }
 serde = { version = "1.0.90", features = ["derive"] }
 serde_json = "1.0.39"
 tiny-keccak = { version = "2.0.1", features = ["keccak"] }
@@ -44,16 +44,24 @@ soketto = { version = "0.4.1", optional = true }
 ## Shared (WS, HTTP)
 native-tls = { version = "0.2", optional = true }
 url = { version = "2.1", optional = true }
+## EIP-1193
+js-sys = { version = "0.3.45", optional = true }
+### This is a transitive dependency, only here so we can turn on its wasm_bindgen feature
+rand = { version = "0.7.3", optional = true }
+wasm-bindgen = { version = "0.2.68", optional = true, features = ["serde-serialize"] }
+wasm-bindgen-futures = { version = "0.4.18", optional = true }
 
 [dev-dependencies]
 # For examples
 env_logger = "0.8"
 tokio = { version = "0.2", features = ["full"] }
 
 [features]
-default = ["http-tls", "ws-tls-tokio"]
+default = ["http-tls", "signing", "ws-tls-tokio"]
+eip-1193 = ["js-sys", "wasm-bindgen", "wasm-bindgen-futures", "futures-timer/wasm-bindgen", "rand/wasm-bindgen"]
 http = ["hyper", "hyper-proxy", "url", "base64", "typed-headers"]
 http-tls = ["hyper-tls", "native-tls", "http"]
+signing = ["secp256k1"]
 ws-tokio = ["soketto", "url", "tokio", "tokio-util"]
 ws-async-std = ["soketto", "url", "async-std"]
 ws-tls-tokio = ["async-native-tls", "native-tls", "async-native-tls/runtime-tokio", "ws-tokio"]