Merge pull request #794 from uuid-rs/feat/getrandom-wasm32

Support forcing `getrandom` on `wasm32-unknown-unknown` without JavaScript

.github/workflows/ci.yml

@@ -133,6 +133,18 @@ jobs:
       - name: Fast RNG
         run: wasm-pack test --node -- --features "js v4 fast-rng"
 
+      - name: rng-getrandom
+        env:
+          RUSTFLAGS: '--cfg getrandom_backend="wasm_js"'
+        working-directory: ./tests/wasm32-getrandom-test
+        run: wasm-pack test --node
+
+      - name: rng-rand
+        env:
+          RUSTFLAGS: '--cfg getrandom_backend="wasm_js"'
+        working-directory: ./tests/wasm32-getrandom-test
+        run: wasm-pack test --node -- --features "rand"
+
   wasi:
     name: Tests / WebAssembly (WASI)
     runs-on: ubuntu-latest

Cargo.toml

@@ -71,6 +71,9 @@ v8 = []
 js = ["dep:wasm-bindgen"]
 
 rng = ["dep:getrandom"]
+rng-getrandom = ["rng", "dep:getrandom", "uuid-rng-internal-lib", "uuid-rng-internal-lib/getrandom"]
+rng-rand = ["rng", "dep:rand", "uuid-rng-internal-lib", "uuid-rng-internal-lib/rand"]
+
 fast-rng = ["rng", "dep:rand"]
 
 sha1 = ["dep:sha1_smol"]
@@ -126,13 +129,20 @@ default-features = false
 # Private
 # (Formally public)
 [target.'cfg(not(all(target_arch = "wasm32", target_vendor = "unknown", target_os = "unknown")))'.dependencies.getrandom]
-optional = true
 version = "0.3"
+optional = true
+
+[target.'cfg(all(target_arch = "wasm32", target_vendor = "unknown", target_os = "unknown"))'.dependencies.uuid-rng-internal-lib]
+# Work-around lack of support for both `dep:x` and `x/` in MSRV
+package = "uuid-rng-internal"
+version = "1.12.1"
+path = "rng"
+optional = true
 
 # Private
 [target.'cfg(not(all(target_arch = "wasm32", target_vendor = "unknown", target_os = "unknown")))'.dependencies.rand]
-optional = true
 version = "0.9"
+optional = true
 
 # Private
 [dependencies.md-5]
@@ -175,7 +185,7 @@ version = "1.0"
 [dev-dependencies.serde_test]
 version = "1.0.56"
 
-[target.'cfg(target = "wasm32-unknown-unknown")'.dev-dependencies.wasm-bindgen]
+[target.'cfg(all(target_arch = "wasm32", target_vendor = "unknown", target_os = "unknown"))'.dev-dependencies.wasm-bindgen]
 version = "0.2"
 
 [target.'cfg(all(target_arch = "wasm32", target_vendor = "unknown", target_os = "unknown"))'.dev-dependencies.wasm-bindgen-test]
@@ -190,6 +200,8 @@ version = "1"
 [workspace]
 members = [
     "macros",
+    "rng",
     "examples",
     "tests/smoke-test",
+    "tests/wasm32-getrandom-test",
 ]

rng/Cargo.toml

@@ -0,0 +1,26 @@
+[package]
+name = "uuid-rng-internal"
+version = "1.12.1"
+edition = "2018"
+authors = [
+    "uuid-rs contributors"
+]
+categories = [
+    "data-structures",
+    "no-std",
+    "parser-implementations",
+    "wasm"
+]
+description = "Private implementation details of the uuid crate."
+documentation = "https://docs.rs/uuid"
+repository = "https://github.com/uuid-rs/uuid"
+license = "Apache-2.0 OR MIT"
+
+# Forces a dependency on `getrandom`
+[dependencies.getrandom]
+version = "0.3"
+optional = true
+
+[dependencies.rand]
+version = "0.9"
+optional = true

rng/src/lib.rs

@@ -0,0 +1,20 @@
+//! Implementation details for the `uuid` crate.
+//!
+//! This crate is not meant to be used directly. It
+//! allows `wasm32-unknown-unknown` users who aren't
+//! in a JS-enabled runtime to configure a source of
+//! randomness via `getrandom`:
+//!
+//! ```toml
+//! [dependencies.uuid]
+//! features = ["v4", "rng-getrandom"]
+//! ```
+
+#[doc(hidden)]
+pub mod __private {
+    #[cfg(feature = "getrandom")]
+    pub use getrandom;
+
+    #[cfg(feature = "rand")]
+    pub use rand;
+}

src/external/serde_support.rs

@@ -145,7 +145,9 @@ impl<'de> Deserialize<'de> for NonNilUuid {
     {
         let uuid = Uuid::deserialize(deserializer)?;
 
-        NonNilUuid::try_from(uuid).map_err(|_| de::Error::invalid_value(de::Unexpected::Other("nil UUID"), &"a non-nil UUID"))
+        NonNilUuid::try_from(uuid).map_err(|_| {
+            de::Error::invalid_value(de::Unexpected::Other("nil UUID"), &"a non-nil UUID")
+        })
     }
 }
 

src/lib.rs

@@ -438,7 +438,13 @@ pub enum Variant {
 // NOTE: Also check `NonNilUuid` when ading new derives here
 #[cfg_attr(
     all(uuid_unstable, feature = "zerocopy"),
-    derive(zerocopy::IntoBytes, zerocopy::FromBytes, zerocopy::KnownLayout, zerocopy::Immutable, zerocopy::Unaligned)
+    derive(
+        zerocopy::IntoBytes,
+        zerocopy::FromBytes,
+        zerocopy::KnownLayout,
+        zerocopy::Immutable,
+        zerocopy::Unaligned
+    )
 )]
 #[cfg_attr(
     feature = "borsh",

src/rng.rs

@@ -1,9 +1,61 @@
-#[cfg(not(all(target_arch = "wasm32", target_vendor = "unknown", target_os = "unknown")))]
+#![allow(dead_code)] // Keeps our cfg's from becoming too convoluted in here
+
+trait Rng {
+    fn u128() -> u128;
+    fn u64() -> u64;
+    fn u16() -> u16;
+}
+
+pub(crate) fn u128() -> u128 {
+    imp::RngImp::u128()
+}
+
+pub(crate) fn u64() -> u64 {
+    imp::RngImp::u64()
+}
+
+pub(crate) fn u16() -> u16 {
+    imp::RngImp::u16()
+}
+
+#[cfg(not(all(
+    target_arch = "wasm32",
+    target_vendor = "unknown",
+    target_os = "unknown"
+)))]
 mod imp {
-    #[cfg(any(feature = "v4", feature = "v7"))]
-    pub(crate) fn u128() -> u128 {
-        #[cfg(not(feature = "fast-rng"))]
-        {
+    /*
+    Random support for non `wasm32-unknown-unknown` platforms.
+    */
+
+    use super::*;
+
+    // Using `rand`
+    #[cfg(any(feature = "rng-rand", feature = "fast-rng"))]
+    pub(super) struct RngImp;
+
+    #[cfg(any(feature = "rng-rand", feature = "fast-rng"))]
+    impl Rng for RngImp {
+        fn u128() -> u128 {
+            rand::random()
+        }
+
+        fn u64() -> u64 {
+            rand::random()
+        }
+
+        fn u16() -> u16 {
+            rand::random()
+        }
+    }
+
+    // Using `getrandom`
+    #[cfg(all(not(feature = "fast-rng"), not(feature = "rng-rand")))]
+    pub(super) struct RngImp;
+
+    #[cfg(all(not(feature = "fast-rng"), not(feature = "rng-rand")))]
+    impl Rng for RngImp {
+        fn u128() -> u128 {
             let mut bytes = [0u8; 16];
 
             getrandom::fill(&mut bytes).unwrap_or_else(|err| {
@@ -14,36 +66,7 @@ mod imp {
             u128::from_ne_bytes(bytes)
         }
 
-        #[cfg(feature = "fast-rng")]
-        {
-            rand::random()
-        }
-    }
-
-    #[cfg(any(feature = "v1", feature = "v6"))]
-    pub(crate) fn u16() -> u16 {
-        #[cfg(not(feature = "fast-rng"))]
-        {
-            let mut bytes = [0u8; 2];
-
-            getrandom::fill(&mut bytes).unwrap_or_else(|err| {
-                // NB: getrandom::Error has no source; this is adequate display
-                panic!("could not retrieve random bytes for uuid: {}", err)
-            });
-
-            u16::from_ne_bytes(bytes)
-        }
-
-        #[cfg(feature = "fast-rng")]
-        {
-            rand::random()
-        }
-    }
-
-    #[cfg(feature = "v7")]
-    pub(crate) fn u64() -> u64 {
-        #[cfg(not(feature = "fast-rng"))]
-        {
+        fn u64() -> u64 {
             let mut bytes = [0u8; 8];
 
             getrandom::fill(&mut bytes).unwrap_or_else(|err| {
@@ -54,56 +77,142 @@ mod imp {
             u64::from_ne_bytes(bytes)
         }
 
-        #[cfg(feature = "fast-rng")]
-        {
-            rand::random()
+        fn u16() -> u16 {
+            let mut bytes = [0u8; 2];
+
+            getrandom::fill(&mut bytes).unwrap_or_else(|err| {
+                // NB: getrandom::Error has no source; this is adequate display
+                panic!("could not retrieve random bytes for uuid: {}", err)
+            });
+
+            u16::from_ne_bytes(bytes)
         }
     }
 }
 
-#[cfg(all(feature = "js", target_arch = "wasm32", target_vendor = "unknown", target_os = "unknown"))]
+#[cfg(all(
+    target_arch = "wasm32",
+    target_vendor = "unknown",
+    target_os = "unknown"
+))]
 mod imp {
     /*
-    This module preserves the stabilized behavior of `uuid` that requires the
-    `js` feature to enable rng on `wasm32-unknown-unknown`, which it inherited
-    from `getrandom` `0.2`
+    Random support for `wasm32-unknown-unknown`.
     */
 
-    #[cfg(any(feature = "v4", feature = "v7"))]
-    pub(crate) fn u128() -> u128 {
-        let mut bytes = [0u8; 16];
+    use super::*;
 
-        if !getrandom::fill(&mut bytes) {
-            panic!("could not retrieve random bytes for uuid")
+    // Using `rand`
+    #[cfg(feature = "rng-rand")]
+    pub(super) struct RngImp;
+
+    #[cfg(feature = "rng-rand")]
+    impl Rng for RngImp {
+        fn u128() -> u128 {
+            uuid_rng_internal_lib::__private::rand::random()
         }
 
-        u128::from_ne_bytes(bytes)
-    }
-
-    #[cfg(any(feature = "v1", feature = "v6"))]
-    pub(crate) fn u16() -> u16 {
-        let mut bytes = [0u8; 2];
-
-        if !getrandom::fill(&mut bytes) {
-            panic!("could not retrieve random bytes for uuid")
+        fn u64() -> u64 {
+            uuid_rng_internal_lib::__private::rand::random()
         }
 
-        u16::from_ne_bytes(bytes)
+        fn u16() -> u16 {
+            uuid_rng_internal_lib::__private::rand::random()
+        }
     }
 
-    #[cfg(feature = "v7")]
-    pub(crate) fn u64() -> u64 {
-        let mut bytes = [0u8; 8];
+    // Using `getrandom`
+    #[cfg(all(feature = "rng-getrandom", not(feature = "rng-rand")))]
+    pub(super) struct RngImp;
 
-        if !getrandom::fill(&mut bytes) {
-            panic!("could not retrieve random bytes for uuid")
+    #[cfg(all(feature = "rng-getrandom", not(feature = "rng-rand")))]
+    impl Rng for RngImp {
+        fn u128() -> u128 {
+            let mut bytes = [0u8; 16];
+
+            uuid_rng_internal_lib::__private::getrandom::fill(&mut bytes).unwrap_or_else(|err| {
+                // NB: getrandom::Error has no source; this is adequate display
+                panic!("could not retrieve random bytes for uuid: {}", err)
+            });
+
+            u128::from_ne_bytes(bytes)
         }
 
-        u64::from_ne_bytes(bytes)
+        fn u64() -> u64 {
+            let mut bytes = [0u8; 8];
+
+            uuid_rng_internal_lib::__private::getrandom::fill(&mut bytes).unwrap_or_else(|err| {
+                // NB: getrandom::Error has no source; this is adequate display
+                panic!("could not retrieve random bytes for uuid: {}", err)
+            });
+
+            u64::from_ne_bytes(bytes)
+        }
+
+        fn u16() -> u16 {
+            let mut bytes = [0u8; 2];
+
+            uuid_rng_internal_lib::__private::getrandom::fill(&mut bytes).unwrap_or_else(|err| {
+                // NB: getrandom::Error has no source; this is adequate display
+                panic!("could not retrieve random bytes for uuid: {}", err)
+            });
+
+            u16::from_ne_bytes(bytes)
+        }
     }
 
-    mod getrandom {
+    // Using WebCrypto via `wasm-bindgen`
+    #[cfg(all(
+        feature = "js",
+        not(feature = "rng-rand"),
+        not(feature = "rng-getrandom")
+    ))]
+    pub(super) struct RngImp;
+
+    #[cfg(all(
+        feature = "js",
+        not(feature = "rng-rand"),
+        not(feature = "rng-getrandom")
+    ))]
+    impl Rng for RngImp {
+        fn u128() -> u128 {
+            let mut bytes = [0u8; 16];
+
+            if !webcrypto::fill(&mut bytes) {
+                panic!("could not retrieve random bytes for uuid")
+            }
+
+            u128::from_ne_bytes(bytes)
+        }
+
+        fn u64() -> u64 {
+            let mut bytes = [0u8; 8];
+
+            if !webcrypto::fill(&mut bytes) {
+                panic!("could not retrieve random bytes for uuid")
+            }
+
+            u64::from_ne_bytes(bytes)
+        }
+
+        fn u16() -> u16 {
+            let mut bytes = [0u8; 2];
+
+            if !webcrypto::fill(&mut bytes) {
+                panic!("could not retrieve random bytes for uuid")
+            }
+
+            u16::from_ne_bytes(bytes)
+        }
+    }
+
+    #[cfg(feature = "js")]
+    mod webcrypto {
         /*
+        This module preserves the stabilized behavior of `uuid` that requires the
+        `js` feature to enable rng on `wasm32-unknown-unknown`, which it inherited
+        from `getrandom` `0.2`.
+
         Vendored from `getrandom`: https://github.com/rust-random/getrandom/blob/ce3b017fdee0233c6ecd61e68b96a84bf6f911bf/src/backends/wasm_js.rs
 
         Copyright (c) 2018-2024 The rust-random Project Developers
@@ -180,7 +289,7 @@ mod imp {
 
                 sub_buf.copy_to_uninit(chunk);
             }
-            
+
             true
         }
 
@@ -196,8 +305,3 @@ mod imp {
         }
     }
 }
-
-#[cfg(all(not(feature = "js"), target_arch = "wasm32", target_vendor = "unknown", target_os = "unknown"))]
-compile_error!("the `js` feature is required for the `wasm32-unknown-unknown` target");
-
-pub(crate) use self::imp::*;

tests/wasm32-getrandom-test/Cargo.toml

@@ -0,0 +1,21 @@
+[package]
+name = "uuid-wasm32-getrandom-test"
+version = "0.1.0"
+edition = "2018"
+
+[features]
+rand = ["uuid/rng-rand"]
+
+[dependencies.uuid]
+path = "../../"
+features = ["v4", "rng-getrandom"]
+
+[dependencies.getrandom]
+version = "0.3"
+features = ["wasm_js"]
+
+[dependencies.wasm-bindgen]
+version = "0.2"
+
+[dependencies.wasm-bindgen-test]
+version = "0.3"

tests/wasm32-getrandom-test/src/lib.rs

@@ -0,0 +1,14 @@
+#![cfg(test)]
+
+use uuid::{Uuid, Variant, Version};
+
+use wasm_bindgen_test::*;
+
+#[test]
+#[wasm_bindgen_test]
+fn test_new() {
+    let uuid = Uuid::new_v4();
+
+    assert_eq!(uuid.get_version(), Some(Version::Random));
+    assert_eq!(uuid.get_variant(), Variant::RFC4122);
+}