Avoid using browser-specific features when building for WASM

Cargo.toml

@@ -56,6 +56,7 @@ default = [
   "tonemapping_luts",
   "default_font",
   "webgl2",
+  "browser",
 ]
 
 # Force dynamic linking, which improves iterative compile times
@@ -244,6 +245,9 @@ shader_format_spirv = ["bevy_internal/shader_format_spirv"]
 # Enable some limitations to be able to use WebGL2. If not enabled, it will default to WebGPU in Wasm
 webgl2 = ["bevy_internal/webgl"]
 
+# When compiling for WebAssembly, enable support for web features
+browser = ["bevy_internal/browser"]
+
 [dependencies]
 bevy_dylib = { path = "crates/bevy_dylib", version = "0.11.0-dev", default-features = false, optional = true }
 bevy_internal = { path = "crates/bevy_internal", version = "0.11.0-dev", default-features = false }

crates/bevy_app/Cargo.toml

@@ -13,6 +13,7 @@ trace = []
 bevy_ci_testing = ["serde", "ron"]
 default = ["bevy_reflect"]
 bevy_reflect = ["dep:bevy_reflect", "bevy_ecs/bevy_reflect"]
+browser = ["dep:wasm-bindgen", "dep:web-sys"]
 
 [dependencies]
 # bevy
@@ -26,8 +27,6 @@ serde = { version = "1.0", features = ["derive"], optional = true }
 ron = { version = "0.8.0", optional = true }
 downcast-rs = "1.2.0"
 
-
 [target.'cfg(target_arch = "wasm32")'.dependencies]
-wasm-bindgen = { version = "0.2" }
-web-sys = { version = "0.3", features = [ "Window" ] }
-
+wasm-bindgen = { version = "0.2", optional = true }
+web-sys = { version = "0.3", features = [ "Window" ], optional = true }

crates/bevy_app/src/schedule_runner.rs

@@ -5,9 +5,9 @@ use crate::{
 use bevy_ecs::event::{Events, ManualEventReader};
 use bevy_utils::{Duration, Instant};
 
-#[cfg(target_arch = "wasm32")]
+#[cfg(all(target_arch = "wasm32", feature = "browser"))]
 use std::{cell::RefCell, rc::Rc};
-#[cfg(target_arch = "wasm32")]
+#[cfg(all(target_arch = "wasm32", feature = "browser"))]
 use wasm_bindgen::{prelude::*, JsCast};
 
 /// Determines the method used to run an [`App`]'s [`Schedule`](bevy_ecs::schedule::Schedule).
@@ -114,7 +114,7 @@ impl Plugin for ScheduleRunnerPlugin {
                         Ok(None)
                     };
 
-                    #[cfg(not(target_arch = "wasm32"))]
+                    #[cfg(any(not(target_arch = "wasm32"), not(feature = "browser")))]
                     {
                         while let Ok(delay) = tick(&mut app, wait) {
                             if let Some(delay) = delay {
@@ -123,7 +123,7 @@ impl Plugin for ScheduleRunnerPlugin {
                         }
                     }
 
-                    #[cfg(target_arch = "wasm32")]
+                    #[cfg(all(target_arch = "wasm32", feature = "browser"))]
                     {
                         fn set_timeout(f: &Closure<dyn FnMut()>, dur: Duration) {
                             web_sys::window()

crates/bevy_asset/Cargo.toml

@@ -12,6 +12,7 @@ keywords = ["bevy"]
 default = []
 filesystem_watcher = ["notify"]
 debug_asset_server = ["filesystem_watcher"]
+browser = ["dep:wasm-bindgen", "dep:web-sys", "dep:wasm-bindgen-futures", "dep:js-sys"]
 
 [dependencies]
 # bevy
@@ -37,10 +38,10 @@ parking_lot = "0.12.1"
 bevy_winit = { path = "../bevy_winit", version = "0.11.0-dev" }
 
 [target.'cfg(target_arch = "wasm32")'.dependencies]
-wasm-bindgen = { version = "0.2" }
-web-sys = { version = "0.3", features = ["Request", "Window", "Response"] }
-wasm-bindgen-futures = "0.4"
-js-sys = "0.3"
+wasm-bindgen = { version = "0.2", optional = true }
+web-sys = { version = "0.3", features = ["Request", "Window", "Response"], optional = true }
+wasm-bindgen-futures = { version = "0.4", optional = true }
+js-sys = { version = "0.3", optional = true }
 
 [dev-dependencies]
 futures-lite = "1.4.0"

crates/bevy_internal/Cargo.toml

@@ -77,6 +77,9 @@ subpixel_glyph_atlas = ["bevy_text/subpixel_glyph_atlas"]
 # Optimise for WebGL2
 webgl = ["bevy_core_pipeline?/webgl", "bevy_pbr?/webgl", "bevy_render?/webgl"]
 
+# When compiling for WebAssembly, enable support for web features
+browser = ["bevy_app/browser", "bevy_asset?/browser", "bevy_tasks/browser", "bevy_log/browser", "bevy_utils/browser"]
+
 # enable systems that allow for automated testing on CI
 bevy_ci_testing = ["bevy_app/bevy_ci_testing", "bevy_time/bevy_ci_testing", "bevy_render?/bevy_ci_testing", "bevy_render?/ci_limits"]
 

crates/bevy_log/Cargo.toml

@@ -11,6 +11,7 @@ keywords = ["bevy"]
 [features]
 trace = [ "tracing-error" ]
 trace_tracy_memory = ["dep:tracy-client"]
+browser = ["dep:console_error_panic_hook", "dep:tracing-wasm"]
 
 [dependencies]
 bevy_app = { path = "../bevy_app", version = "0.11.0-dev" }
@@ -28,5 +29,5 @@ tracy-client = { version = "0.15", optional = true }
 android_log-sys = "0.2.0"
 
 [target.'cfg(target_arch = "wasm32")'.dependencies]
-console_error_panic_hook = "0.1.6"
-tracing-wasm = "0.2.1"
+console_error_panic_hook = { version  = "0.1.6", optional = true }
+tracing-wasm = { version  = "0.2.1", optional = true }

crates/bevy_log/src/lib.rs

@@ -130,7 +130,10 @@ impl Plugin for LogPlugin {
         #[cfg(feature = "trace")]
         let subscriber = subscriber.with(tracing_error::ErrorLayer::default());
 
-        #[cfg(all(not(target_arch = "wasm32"), not(target_os = "android")))]
+        #[cfg(all(
+            any(not(target_arch = "wasm32"), not(feature = "browser")),
+            not(target_os = "android")
+        ))]
         {
             #[cfg(feature = "tracing-chrome")]
             let chrome_layer = {
@@ -179,7 +182,7 @@ impl Plugin for LogPlugin {
             finished_subscriber = subscriber;
         }
 
-        #[cfg(target_arch = "wasm32")]
+        #[cfg(all(target_arch = "wasm32", feature = "browser"))]
         {
             console_error_panic_hook::set_once();
             finished_subscriber = subscriber.with(tracing_wasm::WASMLayer::new(

crates/bevy_tasks/Cargo.toml

@@ -8,6 +8,10 @@ repository = "https://github.com/bevyengine/bevy"
 license = "MIT OR Apache-2.0"
 keywords = ["bevy"]
 
+[features]
+default = []
+browser = ["dep:wasm-bindgen-futures"]
+
 [dependencies]
 futures-lite = "1.4.0"
 async-executor = "1.3.0"
@@ -17,7 +21,7 @@ once_cell = "1.7"
 concurrent-queue = "2.0.0"
 
 [target.'cfg(target_arch = "wasm32")'.dependencies]
-wasm-bindgen-futures = "0.4"
+wasm-bindgen-futures = { version = "0.4", optional = true }
 
 [dev-dependencies]
 instant = { version = "0.1", features = ["wasm-bindgen"] }

crates/bevy_tasks/src/lib.rs

@@ -8,24 +8,24 @@ pub use slice::{ParallelSlice, ParallelSliceMut};
 mod task;
 pub use task::Task;
 
-#[cfg(not(target_arch = "wasm32"))]
+#[cfg(any(not(target_arch = "wasm32"), not(feature = "browser")))]
 mod task_pool;
-#[cfg(not(target_arch = "wasm32"))]
+#[cfg(any(not(target_arch = "wasm32"), not(feature = "browser")))]
 pub use task_pool::{Scope, TaskPool, TaskPoolBuilder};
 
-#[cfg(target_arch = "wasm32")]
+#[cfg(all(target_arch = "wasm32", feature = "browser"))]
 mod single_threaded_task_pool;
-#[cfg(target_arch = "wasm32")]
+#[cfg(all(target_arch = "wasm32", feature = "browser"))]
 pub use single_threaded_task_pool::{Scope, TaskPool, TaskPoolBuilder, ThreadExecutor};
 
 mod usages;
 #[cfg(not(target_arch = "wasm32"))]
 pub use usages::tick_global_task_pools_on_main_thread;
 pub use usages::{AsyncComputeTaskPool, ComputeTaskPool, IoTaskPool};
 
-#[cfg(not(target_arch = "wasm32"))]
+#[cfg(any(not(target_arch = "wasm32"), not(feature = "browser")))]
 mod thread_executor;
-#[cfg(not(target_arch = "wasm32"))]
+#[cfg(any(not(target_arch = "wasm32"), not(feature = "browser")))]
 pub use thread_executor::{ThreadExecutor, ThreadExecutorTicker};
 
 mod iter;

crates/bevy_tasks/src/task_pool.rs

@@ -130,9 +130,12 @@ impl TaskPool {
 
         let executor = Arc::new(async_executor::Executor::new());
 
+        #[cfg(not(target_arch = "wasm32"))]
         let num_threads = builder
             .num_threads
             .unwrap_or_else(crate::available_parallelism);
+        #[cfg(target_arch = "wasm32")]
+        let num_threads = 0;
 
         let threads = (0..num_threads)
             .map(|i| {

crates/bevy_utils/Cargo.toml

@@ -10,6 +10,7 @@ keywords = ["bevy"]
 
 [features]
 detailed_trace = []
+browser = ["dep:getrandom"]
 
 [dependencies]
 ahash = "0.8.3"
@@ -22,4 +23,4 @@ petgraph = "0.6"
 thiserror = "1.0"
 
 [target.'cfg(target_arch = "wasm32")'.dependencies]
-getrandom = {version = "0.2.0", features = ["js"]}
+getrandom = { version = "0.2.0", features = ["js"], optional = true }

docs/cargo_features.md

@@ -27,6 +27,7 @@ The default feature set enables most of the expected features of a game engine,
 |bevy_text|Provides text functionality|
 |bevy_ui|A custom ECS-driven UI framework|
 |bevy_winit|winit window and input backend|
+|browser|When compiling for WebAssembly, enable support for web features|
 |default_font|Include a default font, containing only ASCII characters, at the cost of a 20kB binary size increase|
 |filesystem_watcher|Enable watching file system for asset hot reload|
 |hdr|HDR image format support|