wasm-bindgen Files

Added

• Navigation API to web-sys #5247

• Added riscv64gc-unknown-linux-gnu release artifacts. #5265

• Added JsNullable<T>, modeling WebIDL nullable types (T | null). Both null and undefined are treated as absent, per WebIDL's ECMAScript conversion rules; the canonical empty value produced from Rust is null. web-sys now uses JsNullable<T> instead of JsOption<T> for nullable types nested inside generics (e.g. Promise<GpuError?> from GPUDevice.popErrorScope()), fixing spec-defined null resolutions being treated as present values under JsOption<T>'s strict undefined-only semantics. JsNullable<T> participates in the same upcast lattice as JsOption<T> (including contravariant closure argument casts), and additionally upcasts from Null and from JsOption<T> itself. Imported extern types now also upcast into JsOption<JsValue> and JsNullable<JsValue>, so catch-all nullable closures can be used where a typed callback is expected. #5234

Changed

• Emscripten output now marks public exports (free functions, classes, enums, and namespace roots) with the __export: true and __force: true symbol attributes on their addToLibrary entries, instead of mutating EXPORTED_FUNCTIONS and pushing to extraLibraryFuncs at library-load time. The $initBindgen init closure is kept via __force: true, and private symbols (including namespace leaves) carry neither attribute — they remain reachable through __deps. Requires an emscripten with __export/__force symbol-attribute support.

• Updated WebGPU bindings to the August 2026 spec, including the new GPUCommandEncoder::copy_buffer_to_buffer overloads and setImmediates. #5246

• Unstable API overload names now elide name tokens shared by every overload variant: LockManager::request_with_callback is now request, and request_with_options_and_callback is now request_with_options. #5246

Fixed

• The name property of the JS error thrown for panic=unwind is now set from a string literal instead of PanicError.name, so it survives minification. #5260

• Fixed Emscripten builds using pthreads failing to link. #5254

• __wbg_load in web targets now throws a clear error including the HTTP status and URL when given a non-ok fetch Response, instead of surfacing a misleading MIME-type or Wasm-magic-number error. #5256

• Restored __stack_pointer when an exception unwinds out of a wasm export, preventing repeated panic = "unwind" calls from leaking shadow-stack frames until the shadow stack is exhausted and calls trap. Node reports memory access out of bounds; poisoned instances can instead report Module terminated. #5244

• slice_to_array on a &mut slice (which silently discarded JS's writes) or on a slice with a generic element type is now a compile error, and strings and arrays received by JS (e.g. a Vec<String> return value) no longer make a redundant copy of the freshly built value. #5261

• Fixed async imports with non-JS-handle resolved types (e.g. async fn f() -> u32;) silently producing garbage since 0.2.109: the descriptor named the resolved type instead of the Promise handle that actually crosses the ABI. #5249

• Fixed catch imports returning i64/u64 throwing a TypeError (and panicking in __wbindgen_exn_store) when the JS import throws, since the handleError catch path returned undefined which cannot be converted to a Wasm i64. #5238

• js_namespace is now part of an imported function's and imported static's generated shim name. Two imports with identical Rust signatures that differed only in their js_namespace hashed to the same __wbg_<name>_<hash> symbol, so they were treated as one binding and one of the two call sites silently invoked the wrong JS value. #5250

• Macro hygiene fixes - slice_to_array now works in #![no_std] crates. Generated code no longer names core or std unqualified. #5251

• Fixed length prefixes in descriptor strings to count chars rather than UTF-8 bytes, so non-ASCII names in js_name/typescript_type no longer panic the CLI or mis-bind the generated bindings. #5248

• Fixed threaded Wasm memory layout to reserve wasm-bindgen's internal thread page after the module's original initial memory instead of at __heap_base, avoiding overlap with allocators that resolve __heap_base/__heap_end at link time and treat that range as preexisting heap space. #5225

• Emscripten output now reaches wasm exports through emscripten's wasmExports object using bracket (string-literal) access (wasmExports['__wbindgen_start']) instead of a local wasm alias with dot access. wasmExports['name'] is the form emcc's DCE graph roots and its import/export minifier renames in the JS and the wasm together, so the glue now survives and stays consistent under -O3/-Os (previously the export names were minified without updating the JS call sites, e.g. __wbindgen_start is not defined).

• The emscripten detection marker static is no longer leaked as public API. #5220 #5222