wasm-bindgen 0.2.127

on Rust Cargo

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