Added a CI action for building and checking.

.github/workflows/run-tests.yaml

@@ -0,0 +1,67 @@
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+
+name: Run unit tests
+
+jobs:
+  build:
+    name: ${{ matrix.config.name }}
+    runs-on: ${{ matrix.config.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        config:
+        - {
+            name: "Ubuntu Latest GCC, coverage enabled", 
+            os: ubuntu-latest,
+            cov: true
+          }
+        - {
+            name: "macOS Latest Clang", 
+            os: macos-latest,
+            cov: false
+          }
+
+    steps:
+    - uses: actions/checkout@v4
+
+    - name: Get latest CMake
+      uses: lukka/get-cmake@latest
+
+    - name: Install igraph on Mac
+      if: ${{ matrix.config.os == 'macos-latest' }}
+      run: |
+        brew install igraph
+
+    - name: Install igraph on Ubuntu 
+      if: ${{ matrix.config.os == 'ubuntu-latest' }}
+      run: |
+        sudo apt-get update
+        sudo apt-get install libigraph-dev
+
+    - name: Configure the build
+      if: ${{ matrix.config.cov == false }}
+      run: cmake -S . -B build
+
+    - name: Configure the build with coverage
+      if: ${{ matrix.config.cov == true }}
+      run: cmake -S . -B build -DCODE_COVERAGE=ON
+
+    - name: Run the build
+      run: cmake --build build
+
+    - name: Run the tests
+      run: |
+        cd build
+        ctest
+
+    - name: Upload to Codecov
+      if: ${{ matrix.config.cov == true }}
+      uses: codecov/codecov-action@v4
+      with:
+        directory: build/tests/CMakeFiles/libtest.dir/src/
+      env:
+        CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}