GeoJSON Union WASM

This simple WASM wrapper for geo::algorithm::unary_union to desolve or create the union of one or more GeoJSON strings. I created this because I was trying to combine very large GeoJSON files that took @turf/union longer then I wanted to find the union of. This library for my usecase is approximtely 18 times faster than @turf/union^7.3.1 when creating the uinion of cb_2018_us_county_500k.

Build

wasm-pack build --target bundler

The built code will be in the pkg folder

Usage

Basic dissolve

const unionString = geojson_union([
    `{"features":[
    {"geometry":{"coordinates":[[[4,0],[4,4],[8,4],[8,0],[4,0]]],"type":"Polygon"},"properties":{},"type":"Feature"},
    {"geometry":{"coordinates":[[[0,0],[0,4],[4,4],[4,0],[0,0]]],"type":"Polygon"},"properties":{},"type":"Feature"}],
    "type":"FeatureCollection"}`
]);
console.log('Union result:', JSON.parse(unionString));