Install the Emscripten SDK (version 1.38.41):

git clone https://github.com/emscripten-core/emsdk.git
cd emsdk
./emsdk install 1.38.41
./emsdk activate 1.38.41

Before developing, make sure the environment variable EMSDK points to the emscripten directory (e.g. ~/emsdk). Emscripten provides a script that does the setup for you:

Cd into the emsdk directory and run:

source ./emsdk_env.sh

For details, see instructions here.

yarn build

yarn test

./scripts/build-npm.sh
npm publish