wasm-bindgen 0.2.128 on Rust Cargo

Added

Added OffscreenCanvas overloads for the WebGL texImage2D, texSubImage2D,
texImage3D and texSubImage3D functions, matching the TexImageSource
typedef in the WebGL specification.
#5312
Added --split-debug-info to the CLI. This option extracts the DWARF debug
info to a separate *_bg.debug.wasm file. Use --debug-info-url to set
the recorded URL for the debug info. #5279
Added #[wasm_bindgen(experimental_generic_mono)] for imported functions,
which binds a generic import once per monomorphisation instead of erasing
its type parameters to JsValue. It can be applied to an individual import
or to a whole extern "C" block, which every generic function in the block
then inherits. Each instantiation gets its own descriptor, so arguments and
return values are marshalled at their concrete types (a u32 crosses as a
number, a String as a string) rather than being boxed. Trait bounds,
where predicates (including higher-ranked ones), associated-type
projections, lifetime parameters, argument-position impl Trait, raw
callbacks with owned generic inputs and returns, async, catch, and
slice_to_array are all supported; see
the guide
for the supported surface and the shapes that are rejected. The attribute
is experimental and may change as it stabilizes.
#5230
#5272
#5314
#[wasm_bindgen(experimental_generic_mono)] now supports class-level generic
parameters: an imported type that is itself generic (type Holder<T>),
used as a method receiver (this: &Holder<T>), or as the return type of a
constructor or self-returning static method (fn new<T>(value: T) -> Holder<T>). See Class-level generics
in the guide.
#5290
A generic imported type used as a method receiver or a constructor's return
type may now carry concrete generic arguments (this: &Holder<u32>,
this: &Holder<u32, T>). The arguments are re-emitted as written, so the
generated method hangs off impl Holder<u32> rather than the class's own
parameter defaults.
#5290
Added experimental JSPI (JS Promise Integration) support: using it emits a
compiler warning noting the experimental status.
Supports #[wasm_bindgen(jspi)] on exports (sync or async), within which
a #[wasm_bindgen(suspending)] import call can suspend to the JS event
loop until its Promise settles. js_sys::futures::jspi_block_on_promise
also suspends on any Promise inside a synchronous function, while
spawn_local is context-aware: tasks spawned from within a JSPI context
support synchronous JSPI suspensions throughout their call trees.
Compatible with catch (rejections as Err), async, and
panic=unwind.
#5193
Added a --ts-typed-array-buffers CLI flag to declare owned typed-array
return values (e.g. Vec<u8>) as Uint8Array<ArrayBuffer> in generated
TypeScript, since they are always copied into a fresh, non-shared
ArrayBuffer. Requires TypeScript 5.7+.
#5263

Changed

Export shim symbols are now mangled with a per-crate hash, so identically
named exports from different crates (or two versions of one crate) no
longer fail the link with duplicate-symbol errors; the CLI restores the
canonical names in the final module. Same-named #[wasm_bindgen(private)]
structs/enums now coexist (numbered Name, Name2, ... internally in the
generated bindings), while genuinely conflicting public exports are
reported as a wasm-bindgen error instead of a wasm-ld failure. Requires
matching wasm-bindgen and CLI versions (schema bump).
#2247
Setting js_namespace on both an extern "C" block and an item inside it
is now a hard error. Nested paths must be written in a single attribute,
e.g. js_namespace = ["a", "b"]. The previous behavior silently dropped
the block-level namespace.
#4324
Changed WebGPU setImmediates APIs to take immutable u8 slice.
#5289
Changed Web Bluetooth writeValue / writeValueWithResponse /
writeValueWithoutResponse and WebUSB controlTransferOut / transferOut
/ isochronousTransferOut APIs to take immutable u8 slices.
#5309
Emscripten glue no longer reads wasmExports['name'] inline inside inner
functions. It now references the asmjs-mangled identifiers emcc's own
top-level assignWasmExports receiving code binds for every wasm export
(e.g. ___wbindgen_malloc, ___wbindgen_externrefs), which are the
canonical DCE-graph pairs: wasm-metadce keeps exactly the exports the
included glue uses (previously internal exports and the externref table
could be stripped or left unrenamed by the import/export minifier at -O2,
breaking at runtime). Hoisted classes are now emitted as =-prefixed
string value snippets so jsifier declares them as
export var Class = class Class {...} instead of an export class
declaration, which crashes emcc's acorn-optimizer under
-sMODULARIZE=instance.

Fixed

The thread-bootstrap transform is now skipped in Emscripten mode, where the
Emscripten runtime owns pthread startup and TLS. It previously ran on any
module with shared memory and aborted the build (failed to find __wasm_init_tls), since Emscripten's linker had already consumed the
synthetic symbols it looks for.
#5315
Fixed conflicting deprecation messages on web-sys dictionary fields that
are themselves deprecated: the deprecated builder-style method no longer
points at an equally-deprecated setter, and the WebAuthn fields removed from
the specification (such as PublicKeyCredentialRpEntity's icon) now state
why they are deprecated.
#5302
#[wasm_bindgen] on a struct now reports an actionable error when the path
to the wasm_bindgen crate cannot be resolved (e.g. when wasm-bindgen is
only a transitive dependency through web-sys), instead of a confusing
recursion limit error.
#5295
Fixed js_namespace exports missing from the bundler target's entry module
re-export list, making namespaces unreachable when importing the package.
#5267
The CLI now reports an actionable error when the __wasm_bindgen_unstable
custom section is missing from a module that still contains wasm-bindgen
shims (e.g. stripped by llvm-objcopy --strip-all, which removes all custom
sections since LLVM 23), instead of the confusing
import of `X` doesn't have an adapter listed.
#5268
The generated &T handle conversions (IntoWasmAbi/OptionIntoWasmAbi) for
an imported type with lifetime parameters (type Holder<'a, T>) no longer
reuse 'a for the reference itself. Previously the impl header declared only
a fresh 'a plus the type's type parameters, so a type whose lifetime was
not literally named 'a failed with E0261 against generated code, and one
that was named 'a had its lifetime forced to unify with the borrow of
&self — surfacing as E0521 whenever a generic method also had to resolve
through the same impl.
#5290
An inline lifetime bound on a generic import (fn f<'a: 'b, 'b, T>(..)) is no
longer dropped from the generated wrapper. Previously the bound was lost while
the generated shim still declared it, so calling the import failed with
"lifetime may not live long enough" reported against generated code.
#5290
A type-parameter default on a #[wasm_bindgen(experimental_generic_mono)] import is no
longer silently ignored. It has no meaning there (every instantiation gets its
own shim, so there is no single one to default) and rustc's own
invalid_type_param_default lint cannot see it, since nothing of the original
signature survives expansion; it is now rejected with the same
defaults for generic parameters are not allowed here diagnostic rustc gives.
Defaults on the type-erasure generic path are unaffected, where they remain
meaningful.
#5290
Fix js-sys wasm64 build with atomics feature.
#5274
Declare initSync in the generated TypeScript definitions for
--target no-modules, matching the wasm_bindgen.initSync function that
the JS output already exposes.
#5284
Removed the last panicking code paths from externref table management:
RefCell::borrow_mut() embedded panic location data (including the source
path string) in .rodata of optimized builds, which not even wasm-opt
could remove.
#5292
Fix --no-modules-global being ignored: the custom global name is now used
for the generated JS binding and TypeScript declarations, and the name is
validated as a JS identifier.
#5286