nirs4all-formats (WebAssembly / JS)
Browser- and Node-friendly bridge to the nirs4all-formats Rust core. It runs the
format sniffers and the decoders entirely in WebAssembly, from in-memory
bytes — no filesystem required.
Build
# Browser (ES modules)
wasm-pack build bindings/wasm --target web --release
# Node.js / Bun
wasm-pack build bindings/wasm --target nodejs --release --out-dir pkg-node
This emits the JS glue, .wasm binary, and TypeScript typings under pkg/
(or pkg-node/). Tagged releases publish that surface as
@nirs4all/formats-wasm on npm.
Surface
import init, {
version, features, readerCatalog, probeBytes, openBytes, openWithSidecars,
} from "./pkg/nirs4all_formats_wasm.js";
await init();
version(); // "0.1.0-alpha.1"
features(); // { hdf5: true, matlab: true, parquet: true }
readerCatalog(); // [{ reader: "nirs4all_formats::readers::jcamp" }, ...]
const bytes = new Uint8Array(await file.arrayBuffer());
// Sniff: ordered candidate readers, best first
probeBytes(file.name, bytes);
// [{ format: "jcamp-dx", reader: "...", confidence: "definite", reason: "..." }]
// Decode: SpectralRecord[] (same JSON shape as `nirs4all-formats read-json`)
const records = openBytes(file.name, bytes);
openBytes / probeBytes take the file name (several sniffers
disambiguate by extension) plus the bytes. The returned records match the
data model: signals, signal_type, targets,
metadata, provenance, quality_flags.
Sidecar formats
Multi-file formats (ENVI Standard .img+.hdr, ENVI SLI, AVIRIS/ERDAS LAN,
FGI XML+HDF5, NetCDF MFRSR) return an UnsupportedSidecar error from
openBytes. Supply the companions as a { name: Uint8Array } map instead:
const records = openWithSidecars("cube.img", imgBytes, { "cube.hdr": hdrBytes });
Scope & feature flags
The default WASM build compiles fmt-hdf5, fmt-matlab, and fmt-parquet
on. HDF5/NetCDF-backed readers, MATLAB MAT/RData readers, and Parquet table
readers are available in the browser, including snappy, uncompressed, and
zstd-compressed Parquet pages. Call features() to check the active bundle at
runtime.
Smoke test
node bindings/wasm/tests/smoke.js
node bindings/wasm/tests/sidecars.test.js
node bindings/wasm/tests/fixture_matrix.js
smoke.js loads committed fixtures (CSV, JCAMP-DX, ASD binary, a non-data PDF)
and asserts the probe routes each to the expected reader; sidecars.test.js
exercises openWithSidecars. fixture_matrix.js opens a wider set of committed
single-file and sidecar fixtures through the WASM package, checks expected
non-NIRS/refusal paths, and compares the exercised readers to
readerCatalog(). The committed matrix covers every compiled reader except
Allotrope ADF, whose sample is local-only/non-redistributable; see
samples/allotrope_adf/README.md.