Support webusb as a backend

.cargo/config.toml

@@ -0,0 +1,2 @@
+[target.wasm32-unknown-unknown]
+rustflags = "--cfg=web_sys_unstable_apis"

.github/workflows/rust.yml

@@ -2,9 +2,9 @@ name: Rust
 
 on:
   push:
-    branches: [ "main" ]
+    branches: ["main"]
   pull_request:
-    branches: [ "main" ]
+    branches: ["main"]
 
 env:
   CARGO_TERM_COLOR: always
@@ -21,35 +21,47 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest, windows-latest, macos-latest]
-        rust: ['stable', '1.79']
+        rust: ["stable", "1.80"]
 
     runs-on: ${{ matrix.os }}
 
     steps:
-    - uses: actions/checkout@v3
-    - name: Install toolchain
-      uses: dtolnay/rust-toolchain@stable
-      with:
-        toolchain: ${{ matrix.rust }}
-        override: true
-    - name: Build
-      run: cargo build --verbose
-    - name: Run tests
-      run: |
-        cargo test --verbose
-        cargo test --verbose --features tokio
-        cargo test --verbose --features smol
-        cargo test --verbose --features smol,tokio
+      - uses: actions/checkout@v3
+      - name: Install toolchain
+        uses: dtolnay/rust-toolchain@stable
+        with:
+          toolchain: ${{ matrix.rust }}
+          override: true
+      - name: Build
+        run: cargo build --verbose
+      - name: Run tests
+        run: |
+          cargo test --verbose
+          cargo test --verbose --features tokio
+          cargo test --verbose --features smol
+          cargo test --verbose --features smol,tokio
 
   build_android:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v4
-    - name: Install toolchain
-      uses: dtolnay/rust-toolchain@stable
-      with:
-        targets: 'aarch64-linux-android, armv7-linux-androideabi'
-    - name: build
-      run: |
-        cargo build --target aarch64-linux-android --all-features
-        cargo build --target armv7-linux-androideabi --all-features
+      - uses: actions/checkout@v4
+      - name: Install toolchain
+        uses: dtolnay/rust-toolchain@stable
+        with:
+          targets: "aarch64-linux-android, armv7-linux-androideabi"
+      - name: build
+        run: |
+          cargo build --target aarch64-linux-android --all-features
+          cargo build --target armv7-linux-androideabi --all-features
+
+  build_wasm32:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: Install toolchain
+        uses: dtolnay/rust-toolchain@stable
+        with:
+          targets: "wasm32-unknown-unknown"
+      - name: build
+        run: |
+          cargo build --target wasm32-unknown-unknown --all-features

.vscode/settings.json

@@ -0,0 +1,5 @@
+{
+  "rust-analyzer.check.targets": ["wasm32-unknown-unknown"],
+  "rust-analyzer.cargo.target": "wasm32-unknown-unknown",
+  "rust-analyzer.showUnlinkedFileNotification": false
+}

Cargo.toml

@@ -8,25 +8,39 @@ authors = ["Kevin Mehall <km@kevinmehall.net>"]
 edition = "2021"
 license = "Apache-2.0 OR MIT"
 repository = "https://github.com/kevinmehall/nusb"
-rust-version = "1.79" # keep in sync with .github/workflows/rust.yml
+rust-version = "1.80"                                                       # keep in sync with .github/workflows/rust.yml
 
 [dependencies]
 atomic-waker = "1.1.2"
 futures-core = "0.3.29"
 log = "0.4.20"
 once_cell = "1.18.0"
 slab = "0.4.9"
+tracing = "0.1"
 
 [dev-dependencies]
 env_logger = "0.10.0"
 futures-lite = "1.13.0"
+pollster = { version = "0.4", features = ["macro"] }
 
 [target.'cfg(any(target_os="linux", target_os="android"))'.dependencies]
-rustix = { version = "1.0.1", features = ["fs", "event", "net", "time", "mm"] }
 linux-raw-sys = { version = "0.9.2", features = ["ioctl"] }
 
+[target.'cfg(all(any(target_os="linux", target_os="android"), not(target_arch="wasm32")))'.dependencies]
+rustix = { version = "1.0.1", features = ["fs", "event", "net", "time", "mm"] }
+
 [target.'cfg(target_os="windows")'.dependencies]
-windows-sys = { version = "0.59.0", features = ["Win32_Devices_Usb", "Win32_Devices_DeviceAndDriverInstallation", "Win32_Foundation", "Win32_Devices_Properties", "Win32_Storage_FileSystem", "Win32_Security", "Win32_System_IO", "Win32_System_Registry", "Win32_System_Com"] }
+windows-sys = { version = "0.59.0", features = [
+    "Win32_Devices_Usb",
+    "Win32_Devices_DeviceAndDriverInstallation",
+    "Win32_Foundation",
+    "Win32_Devices_Properties",
+    "Win32_Storage_FileSystem",
+    "Win32_Security",
+    "Win32_System_IO",
+    "Win32_System_Registry",
+    "Win32_System_Com",
+] }
 
 [target.'cfg(target_os="macos")'.dependencies]
 core-foundation = "0.9.3"
@@ -37,13 +51,37 @@ io-kit-sys = "0.4.0"
 blocking = { version = "1.6.1", optional = true }
 tokio = { version = "1", optional = true, features = ["rt"] }
 
+
+[target.'cfg(target_arch="wasm32")'.dependencies]
+web-sys = { version = "*", features = [
+    "Document",
+    "Window",
+    "Navigator",
+    "Usb",
+    "UsbDevice",
+    "UsbDeviceRequestOptions",
+    "UsbConfiguration",
+    "UsbInterface",
+    "UsbAlternateInterface",
+    "UsbControlTransferParameters",
+    "UsbRequestType",
+    "UsbRecipient",
+    "UsbInTransferResult",
+    "UsbTransferStatus",
+    "UsbOutTransferResult",
+    "UsbDirection",
+    "UsbConnectionEvent",
+    "WorkerGlobalScope",
+    "WorkerNavigator",
+] }
+wasm-bindgen-futures = { version = "*" }
+
 [features]
 # Use the `blocking` crate for making blocking IO async
 smol = ["dep:blocking"]
 
 # Use `tokio`'s IO threadpool for making blocking IO async
 tokio = ["dep:tokio"]
 
-
 [lints.rust]
 unexpected_cfgs = { level = "warn", check-cfg = ['cfg(fuzzing)'] }

examples/control.rs

@@ -4,7 +4,6 @@ use nusb::{
     transfer::{ControlIn, ControlOut, ControlType, Recipient},
     MaybeFuture,
 };
-
 fn main() {
     env_logger::init();
     let di = nusb::list_devices()

examples/descriptors.rs

@@ -37,6 +37,6 @@ fn inspect_device(dev: DeviceInfo) {
     for config in dev.configurations() {
         println!("{config:#?}");
     }
-    println!("");
-    println!("");
+    println!();
+    println!();
 }

examples/string_descriptors.rs

@@ -61,5 +61,5 @@ fn inspect_device(dev: DeviceInfo) {
         println!("  Serial({i_serial}): {s:?}");
     }
 
-    println!("");
+    println!();
 }

src/descriptors.rs

@@ -18,15 +18,22 @@ use crate::{transfer::Direction, Error};
 pub(crate) const DESCRIPTOR_TYPE_DEVICE: u8 = 0x01;
 pub(crate) const DESCRIPTOR_LEN_DEVICE: u8 = 18;
 
+/// https://www.beyondlogic.org/usbnutshell/usb5.shtml#ConfigurationDescriptors
 pub(crate) const DESCRIPTOR_TYPE_CONFIGURATION: u8 = 0x02;
+/// https://www.beyondlogic.org/usbnutshell/usb5.shtml#ConfigurationDescriptors
 pub(crate) const DESCRIPTOR_LEN_CONFIGURATION: u8 = 9;
 
+/// https://www.beyondlogic.org/usbnutshell/usb5.shtml#ConfigurationDescriptors
 pub(crate) const DESCRIPTOR_TYPE_INTERFACE: u8 = 0x04;
+/// https://www.beyondlogic.org/usbnutshell/usb5.shtml#ConfigurationDescriptors
 pub(crate) const DESCRIPTOR_LEN_INTERFACE: u8 = 9;
 
+/// https://www.beyondlogic.org/usbnutshell/usb5.shtml#ConfigurationDescriptors
 pub(crate) const DESCRIPTOR_TYPE_ENDPOINT: u8 = 0x05;
+/// https://www.beyondlogic.org/usbnutshell/usb5.shtml#ConfigurationDescriptors
 pub(crate) const DESCRIPTOR_LEN_ENDPOINT: u8 = 7;
 
+/// https://www.beyondlogic.org/usbnutshell/usb5.shtml#ConfigurationDescriptors
 pub(crate) const DESCRIPTOR_TYPE_STRING: u8 = 0x03;
 
 /// USB defined language IDs for string descriptors.
@@ -46,7 +53,7 @@ pub mod language_id {
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct Descriptor<'a>(&'a [u8]);
 
-impl<'a> Descriptor<'a> {
+impl Descriptor<'_> {
     /// Create a `Descriptor` from a buffer.
     ///
     /// Returns `None` if
@@ -73,7 +80,7 @@ impl<'a> Descriptor<'a> {
     }
 }
 
-impl<'a> Deref for Descriptor<'a> {
+impl Deref for Descriptor<'_> {
     type Target = [u8];
 
     fn deref(&self) -> &[u8] {
@@ -192,7 +199,7 @@ impl DeviceDescriptor {
     /// This ignores any trailing data after the `bLength` specified in the descriptor.
     pub fn new(buf: &[u8]) -> Option<Self> {
         let Some(buf) = buf.get(0..DESCRIPTOR_LEN_DEVICE as usize) else {
-            if buf.len() != 0 {
+            if !buf.is_empty() {
                 warn!(
                     "device descriptor buffer is {} bytes, need {}",
                     buf.len(),
@@ -203,7 +210,7 @@ impl DeviceDescriptor {
         };
         let buf: [u8; DESCRIPTOR_LEN_DEVICE as usize] = buf.try_into().ok()?;
         if buf[0] < DESCRIPTOR_LEN_DEVICE {
-            warn!("invalid device descriptor bLength");
+            warn!("invalid config descriptor bLength. expected {DESCRIPTOR_LEN_CONFIGURATION}, got {}", buf[0]);
             None
         } else if buf[1] != DESCRIPTOR_TYPE_DEVICE {
             warn!(
@@ -221,7 +228,7 @@ impl DeviceDescriptor {
         &self.0
     }
 
-    #[allow(unused)]
+    #[allow(unused, clippy::too_many_arguments)]
     pub(crate) fn from_fields(
         usb_version: u16,
         class: u8,
@@ -360,7 +367,7 @@ impl<'a> ConfigurationDescriptor<'a> {
     /// This ignores any trailing data after the length specified in `wTotalLen`.
     pub fn new(buf: &[u8]) -> Option<ConfigurationDescriptor> {
         if buf.len() < DESCRIPTOR_LEN_CONFIGURATION as usize {
-            if buf.len() != 0 {
+            if !buf.is_empty() {
                 warn!(
                     "config descriptor buffer is {} bytes, need {}",
                     buf.len(),
@@ -463,7 +470,7 @@ descriptor_fields! {
     }
 }
 
-impl<'a> ConfigurationDescriptor<'a> {
+impl ConfigurationDescriptor<'_> {
     /// Index of the string descriptor describing this configuration.
     #[doc(alias = "iConfiguration")]
     pub fn string_index(&self) -> Option<NonZeroU8> {
@@ -484,7 +491,7 @@ where
     }
 }
 
-impl<'a> Debug for ConfigurationDescriptor<'a> {
+impl Debug for ConfigurationDescriptor<'_> {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         f.debug_struct("Configuration")
             .field("configuration_value", &self.configuration_value())
@@ -591,15 +598,15 @@ descriptor_fields! {
     }
 }
 
-impl<'a> InterfaceDescriptor<'a> {
+impl InterfaceDescriptor<'_> {
     /// Index of the string descriptor describing this interface or alternate setting.
     #[doc(alias = "iInterface")]
     pub fn string_index(&self) -> Option<NonZeroU8> {
         NonZeroU8::new(self.string_index_raw())
     }
 }
 
-impl<'a> Debug for InterfaceDescriptor<'a> {
+impl Debug for InterfaceDescriptor<'_> {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         f.debug_struct("InterfaceAltSetting")
             .field("interface_number", &self.interface_number())
@@ -680,7 +687,7 @@ descriptor_fields! {
     }
 }
 
-impl<'a> Debug for EndpointDescriptor<'a> {
+impl Debug for EndpointDescriptor<'_> {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         f.debug_struct("Endpoint")
             .field("address", &format_args!("0x{:02X}", self.address()))
@@ -738,6 +745,7 @@ impl From<ActiveConfigurationError> for Error {
     }
 }
 
+#[cfg(not(target_arch = "wasm32"))]
 /// Split a chain of concatenated configuration descriptors by `wTotalLength`
 #[allow(unused)]
 pub(crate) fn parse_concatenated_config_descriptors(
@@ -774,6 +782,7 @@ pub fn fuzz_parse_concatenated_config_descriptors(buf: &[u8]) -> impl Iterator<I
     parse_concatenated_config_descriptors(buf)
 }
 
+#[cfg(not(target_arch = "wasm32"))]
 #[cfg(test)]
 mod test_concatenated {
     use super::parse_concatenated_config_descriptors;

src/device.rs

@@ -139,7 +139,7 @@ impl Device {
 
         self.configurations()
             .find(|c| c.configuration_value() == active)
-            .ok_or_else(|| ActiveConfigurationError {
+            .ok_or(ActiveConfigurationError {
                 configuration_value: active,
             })
     }
@@ -190,7 +190,7 @@ impl Device {
                 .get_descriptor(desc_type, desc_index, language_id)
         }
 
-        #[cfg(not(target_os = "windows"))]
+        #[cfg(not(any(target_os = "windows", target_family = "wasm")))]
         {
             const STANDARD_REQUEST_GET_DESCRIPTOR: u8 = 0x06;
             use crate::transfer::{ControlType, Recipient};
@@ -208,6 +208,16 @@ impl Device {
             )
             .map(|r| Ok(r?))
         }
+
+        #[cfg(target_family = "wasm")]
+        {
+            let device = self.backend.clone();
+            crate::maybe_future::future::ActualFuture::new(async move {
+                device
+                    .get_descriptor(desc_type, desc_index, language_id, timeout)
+                    .await
+            })
+        }
     }
 
     /// Request the list of supported languages for string descriptors.
@@ -661,7 +671,7 @@ impl<EpType: BulkOrInterrupt, Dir: EndpointDirection> Endpoint<EpType, Dir> {
     ///
     /// ## Panics
     ///  * if there are no transfers pending (that is, if [`Self::pending()`]
-    /// would return 0).
+    ///    would return 0).
     pub fn poll_next_complete(&mut self, cx: &mut Context<'_>) -> Poll<Completion> {
         self.backend.poll_next_complete(cx)
     }
@@ -676,7 +686,8 @@ impl<EpType: BulkOrInterrupt, Dir: EndpointDirection> Endpoint<EpType, Dir> {
     ///
     /// ## Panics
     ///  * if there are no transfers pending (that is, if [`Self::pending()`]
-    /// would return 0).
+    ///    would return 0).
+    #[cfg(not(target_arch = "wasm32"))]
     pub fn wait_next_complete(&mut self, timeout: Duration) -> Option<Completion> {
         self.backend.wait_next_complete(timeout)
     }
@@ -697,6 +708,7 @@ impl<EpType: BulkOrInterrupt, Dir: EndpointDirection> Endpoint<EpType, Dir> {
     }
 }
 
+#[cfg(not(target_arch = "wasm32"))]
 #[test]
 fn assert_send_sync() {
     use crate::transfer::{Bulk, In, Interrupt, Out};