Implement an iterative Poisson solver #318

	name: Run unit tests

	on:
	pull_request:
	paths:
	- 'src/**'
	- 'tests/**'
	- '.github/workflows/build_and_test.yml'

	jobs:
	unit-tests:
	runs-on: ubuntu-20.04
	env:
	OMPI_VERSION: 4.1.5
	steps:

	- uses: actions/checkout@v4

	# We don't want to build openmpi each time this workflow is
	# run. Setup caching of OpenMPI after it is built and installed.
	# See "Caching dependencies to speed up workflows" on the GH
	# actions docs.
	- name: Cache OpenMPI
	id: cache-openmpi
	uses: actions/cache@v4
	with:
	path: openmpi-${{ env.OMPI_VERSION }}/installed
	key: openmpi-${{ env.OMPI_VERSION }}
	save-always: 'true'

	- name: Display GCC version number
	run: gcc --version

	- name: Build openmpi
	if: steps.cache-openmpi.outputs.cache-hit != 'true'
	run: \|
	wget https://download.open-mpi.org/release/open-mpi/v4.1/openmpi-$OMPI_VERSION.tar.gz
	tar -xf openmpi-$OMPI_VERSION.tar.gz
	cd openmpi-$OMPI_VERSION/ && mkdir installed
	./configure --prefix=$(pwd)/installed
	make all install

	- name: Update PATH
	run: \|
	echo "$GITHUB_WORKSPACE/openmpi-${OMPI_VERSION}/installed/bin" \
	>> $GITHUB_PATH

	- name: Configure Debug build
	run: FC=mpif90 cmake -S . -B build -DCMAKE_BUILD_TYPE=Debug

	- name: Build with Debug (strict) flags
	run: make -C build

	- name: Configure Release build
	run: FC=mpif90 cmake -S . -B build -DCMAKE_BUILD_TYPE=Release

	- name: Build tests
	run: make -C build

	- name: Run the tests
	run: make -C build test

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