tx: add support for computing an elements transaction discount #350

	name: Build NPM package

	on:
	push:
	branches:
	- master
	pull_request:
	branches:
	- master

	jobs:
	build:
	runs-on: ubuntu-20.04

	steps:
	- uses: actions/checkout@v3
	with:
	submodules: true

	# Needed for build_wrappers.py, to extract function signatures from source code
	# We sed out azure to attempt to mitigate apt network failues.
	- run: sudo sed -i 's/azure\.//' /etc/apt/sources.list

	# bullseye_deps.sh is written for Debian, but works as-is on Ubuntu too.
	# Skip installing Java (-j), the Android NDK (-n) and MinGW (-w) which
	# we don't need for building the NPM package.
	- run: sudo contrib/bullseye_deps.sh -j -n -w

	# Build NPM package into a tgz file (pack internally triggers the build/prepare script)
	- run: cd src/wasm_package && npm ci && npm pack --foreground-scripts
	name: Build & Pack

	# Report the SHA256 digest of the final package. This should be deterministic (including generated WASM),
	# so it should match the package published to the NPM registry and can be used to cross-check its integrity.
	- run: 'echo SHA256 digest: && sha256sum src/wasm_package/wallycore-*.tgz'

	- run: cd src/wasm_package && npm test

	- uses: actions/upload-artifact@v3
	with:
	name: libwally-npm
	path: src/wasm_package/wallycore-*.tgz

Provide feedback