custom: Add custom RNG for stdweb

Author: josephlr

.travis.yml

@@ -71,8 +71,9 @@ matrix:
         # wasi tests
         - cargo test --target wasm32-wasi
         # stdweb tests (Node, Chrome)
-        - cargo web test --nodejs --target=wasm32-unknown-unknown --features=stdweb
-        - cargo web test --target=wasm32-unknown-unknown --features=stdweb
+        - cd custom/stdweb
+        - cargo web test --nodejs --target=wasm32-unknown-unknown
+        - cargo web test --target=wasm32-unknown-unknown
         # wasm-bindgen tests (Node, Firefox, Chrome)
         - cargo test --target wasm32-unknown-unknown --features=wasm-bindgen
         - GECKODRIVER=$HOME/geckodriver cargo test --target wasm32-unknown-unknown --features=test-in-browser

Cargo.toml

@@ -14,6 +14,11 @@ exclude = ["utils/*", ".*", "appveyor.yml"]
 travis-ci = { repository = "rust-random/getrandom" }
 appveyor = { repository = "rust-random/getrandom" }
 
+[workspace]
+members = [
+    "custom/stdweb",
+]
+
 [dependencies]
 log = { version = "0.4", optional = true }
 cfg-if = "0.1.2"

custom/stdweb/Cargo.toml

@@ -0,0 +1,26 @@
+[package]
+name = "stdweb-getrandom"
+version = "0.1.0"
+edition = "2018"
+authors = ["The Rand Project Developers"]
+license = "MIT OR Apache-2.0"
+description = "Custom shim for using getrandom with stdweb"
+documentation = "https://docs.rs/stdweb-getrandom"
+repository = "https://github.com/rust-random/getrandom"
+categories = ["wasm"]
+
+[dependencies]
+getrandom = { path = "../..", version = "0.2", features = ["custom"] }
+stdweb = "0.4.18"
+
+# Test-only features allowing us to reuse most of the code in common.rs
+[features]
+default = ["test-stdweb"]
+test-stdweb = []
+
+[[test]]
+name = "common"
+path = "../../tests/common.rs"
+
+[package.metadata.docs.rs]
+default-target = "wasm32-unknown-unknown"

src/wasm32_stdweb.rs renamed to custom/stdweb/src/lib.rs

@@ -6,8 +6,9 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-//! Implementation for WASM via stdweb
-extern crate std;
+#![recursion_limit = "128"]
+#[cfg(not(all(target_arch = "wasm32", target_os = "unknown")))]
+compile_error!("This crate is only for the `wasm32-unknown-unknown` target");
 
 use core::mem;
 use std::sync::Once;
@@ -16,15 +17,17 @@ use stdweb::js;
 use stdweb::unstable::TryInto;
 use stdweb::web::error::Error as WebError;
 
-use crate::Error;
+use getrandom::{register_custom_getrandom, Error};
 
 #[derive(Clone, Copy, Debug)]
 enum RngSource {
     Browser,
     Node,
 }
 
-pub fn getrandom_inner(dest: &mut [u8]) -> Result<(), Error> {
+register_custom_getrandom!(getrandom_inner);
+
+fn getrandom_inner(dest: &mut [u8]) -> Result<(), Error> {
     assert_eq!(mem::size_of::<usize>(), 4);
     static ONCE: Once = Once::new();
     static mut RNG_SOURCE: Result<RngSource, Error> = Ok(RngSource::Node);
@@ -68,8 +71,6 @@ fn getrandom_init() -> Result<RngSource, Error> {
             unreachable!()
         }
     } else {
-        let _err: WebError = js! { return @{ result }.error }.try_into().unwrap();
-        error!("getrandom unavailable: {}", _err);
         Err(Error::STDWEB_NO_RNG)
     }
 }
@@ -104,8 +105,6 @@ fn getrandom_fill(source: RngSource, dest: &mut [u8]) -> Result<(), Error> {
         };
 
         if js! { return @{ result.as_ref() }.success } != true {
-            let _err: WebError = js! { return @{ result }.error }.try_into().unwrap();
-            error!("getrandom failed: {}", _err);
             return Err(Error::STDWEB_RNG_FAILED);
         }
     }

tests/common.rs

@@ -1,3 +1,7 @@
+// Explicitly use the Custom RNG crates to link them in.
+#[cfg(feature = "test-stdweb")]
+use stdweb_getrandom as _;
+
 #[cfg(feature = "wasm-bindgen")]
 use wasm_bindgen_test::*;