custom: Add Custom RNG for wasm-bindgen

Author: josephlr

.travis.yml

@@ -75,7 +75,8 @@ matrix:
         - 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
+        - cd ../wasm-bindgen
+        - cargo test --target wasm32-unknown-unknown
         - GECKODRIVER=$HOME/geckodriver cargo test --target wasm32-unknown-unknown --features=test-in-browser
         - CHROMEDRIVER=$HOME/chromedriver cargo test --target wasm32-unknown-unknown --features=test-in-browser
 
@@ -97,6 +98,7 @@ matrix:
         # remove cached documentation, otherwise files from previous PRs can get included
         - rm -rf target/doc
         - cargo doc --no-deps --features=std,custom
+        - cargo doc --no-deps --manifest-path=custom/wasm-bindgen/Cargo.toml --target=wasm32-unknown-unknown
         - cargo deadlinks --dir target/doc
         # also test minimum dependency versions are usable
         - cargo generate-lockfile -Z minimal-versions

Cargo.toml

@@ -17,6 +17,7 @@ appveyor = { repository = "rust-random/getrandom" }
 [workspace]
 members = [
     "custom/stdweb",
+    "custom/wasm-bindgen",
 ]
 
 [dependencies]

custom/wasm-bindgen/Cargo.toml

@@ -0,0 +1,30 @@
+[package]
+name = "wasm-bindgen-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 wasm-bindgen"
+documentation = "https://docs.rs/wasm-bindgen-getrandom"
+repository = "https://github.com/rust-random/getrandom"
+categories = ["wasm"]
+
+[dependencies]
+getrandom = { path = "../..", version = "0.2", features = ["custom"] }
+wasm-bindgen = "0.2.29"
+
+[dev-dependencies]
+wasm-bindgen-test = "0.2"
+
+# Test-only features allowing us to reuse most of the code in common.rs
+[features]
+default = ["test-bindgen"]
+test-bindgen = []
+test-in-browser = ["test-bindgen"]
+
+[[test]]
+name = "common"
+path = "../../tests/common.rs"
+
+[package.metadata.docs.rs]
+default-target = "wasm32-unknown-unknown"

src/wasm32_bindgen.rs custom/wasm-bindgen/src/lib.rs

@@ -6,16 +6,16 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-//! Implementation for WASM via wasm-bindgen
-extern crate std;
+#[cfg(not(all(target_arch = "wasm32", target_os = "unknown")))]
+compile_error!("This crate is only for the `wasm32-unknown-unknown` target");
 
 use core::cell::RefCell;
 use core::mem;
 use std::thread_local;
 
 use wasm_bindgen::prelude::*;
 
-use crate::Error;
+use getrandom::{register_custom_getrandom, Error};
 
 #[derive(Clone, Debug)]
 enum RngSource {
@@ -29,7 +29,9 @@ thread_local!(
     static RNG_SOURCE: RefCell<Option<RngSource>> = RefCell::new(None);
 );
 
-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);
 
     RNG_SOURCE.with(|f| {

tests/common.rs

@@ -1,23 +1,25 @@
 // Explicitly use the Custom RNG crates to link them in.
 #[cfg(feature = "test-stdweb")]
 use stdweb_getrandom as _;
+#[cfg(feature = "test-bindgen")]
+use wasm_bindgen_getrandom as _;
 
-#[cfg(feature = "wasm-bindgen")]
+#[cfg(feature = "test-bindgen")]
 use wasm_bindgen_test::*;
 
 use getrandom::getrandom;
 
 #[cfg(feature = "test-in-browser")]
 wasm_bindgen_test_configure!(run_in_browser);
 
-#[cfg_attr(feature = "wasm-bindgen", wasm_bindgen_test)]
+#[cfg_attr(feature = "test-bindgen", wasm_bindgen_test)]
 #[test]
 fn test_zero() {
     // Test that APIs are happy with zero-length requests
     getrandom(&mut [0u8; 0]).unwrap();
 }
 
-#[cfg_attr(feature = "wasm-bindgen", wasm_bindgen_test)]
+#[cfg_attr(feature = "test-bindgen", wasm_bindgen_test)]
 #[test]
 fn test_diff() {
     let mut v1 = [0u8; 1000];
@@ -35,7 +37,7 @@ fn test_diff() {
     assert!(n_diff_bits >= v1.len() as u32);
 }
 
-#[cfg_attr(feature = "wasm-bindgen", wasm_bindgen_test)]
+#[cfg_attr(feature = "test-bindgen", wasm_bindgen_test)]
 #[test]
 fn test_huge() {
     let mut huge = [0u8; 100_000];