geocoordinates (WebAssembly / TypeScript)

WebAssembly bindings for the geocoordinates geospatial library — China datums (GCJ-02 / BD-09), geodetic transforms — generated from the geocoordinates-ffi UniFFI surface with uniffi-bindgen-react-native (ubrn) targeting wasm32-unknown-unknown.

This package is the hand-authored source of the npm package. The actual bindings (src/generated/, src/index.web.ts) and the wasm wrapper crate (rust_modules/) are generated and git-ignored; rebuild them with npm run build.

Build

Prerequisites: a Rust toolchain with the wasm32-unknown-unknown target, wasm-pack on PATH, and Node.js.

npm ci
npm run build      # generate TS + wasm, then type-check (see build.sh)

build.sh documents the two ubrn pre-1.0 quirks it works around (the wrapper crate is regenerated each run, and its opt-level is emitted as a string).

Usage

The wasm module loads asynchronously, so initialize once before calling the API:

import GeoCoordinates, { uniffiInitAsync, wgs84ToGcj02, coordinateWgs84 } from "geocoordinates";

await uniffiInitAsync();

const gcj = wgs84ToGcj02({ lat: 39.9, lon: 116.4 });

Bundler notes:

• Webpack: enable experiments.asyncWebAssembly = true.
• The package targets ES2021+ (the runtime uses FinalizationRegistry).

Node.js consumers are not the target of this WASM build (the generated loader is web/bundler-shaped). A dedicated Node target is tracked separately.