add unit tests.

.github/workflows/macos-unit.yml

@@ -0,0 +1,34 @@
+name: macOS unit
+# adapted from: https://github.com/trase-cpp/trase/tree/master/.github/workflows
+on:
+  push:
+    branches:
+      - master
+      #- develop
+  pull_request:
+    branches:
+      - '**'
+
+jobs:
+
+  build-and-test:
+    name: macOS unit
+    runs-on: macos-latest
+
+    steps:
+      - uses: actions/checkout@v3
+
+      - name: make build directory
+        run: mkdir build_dir
+
+      - name: cmake configure
+        run: cmake .. -DCMAKE_BUILD_TYPE=Debug
+        working-directory: build_dir
+
+      - name: cmake build
+        run: cmake --build . --parallel 2
+        working-directory: build_dir
+
+      - name: cmake test
+        run: ctest -j2 -C Debug --output-on-failure
+        working-directory: build_dir

.github/workflows/ubuntu-unit.yml

@@ -0,0 +1,76 @@
+name: Ubuntu unit
+# adapted from: https://github.com/trase-cpp/trase/tree/master/.github/workflows
+on:
+  push:
+    branches:
+      - master
+      #- develop
+  pull_request:
+    branches:
+      - '**'
+
+jobs:
+
+  build-and-test:
+    name: Ubuntu unit ${{matrix.CC}}
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - CC: gcc-10
+            CXX: g++-10
+            compiler: gcc-10 g++-10
+          - CC: gcc-11
+            CXX: g++-11
+            compiler: gcc-11 g++-11
+          - CC: gcc-12
+            CXX: g++-12
+            compiler: gcc-12 g++-12
+          - CC: gcc-13
+            CXX: g++-13
+            compiler: gcc-13 g++-13
+          - CC: clang-12
+            CXX: clang++-12
+            compiler: clang-12
+          - CC: clang-13
+            CXX: clang++-13
+            compiler: clang-13
+          - CC: clang-14
+            CXX: clang++-14
+            compiler: clang-14
+          - CC: clang-15
+            CXX: clang++-15
+            compiler: clang-15
+          - CC: clang-16
+            CXX: clang++-16
+            compiler: clang-16
+          - CC: clang-17
+            CXX: clang++-17
+            compiler: clang-17
+    steps:
+      - uses: actions/checkout@v3
+
+      - name: update
+        run: sudo apt update
+
+      - name: install compiler
+        run: sudo apt install ${{matrix.compiler}}
+
+      - name: make build directory
+        run: mkdir build_dir
+
+      - name: cmake configure
+        run: cmake .. -DCMAKE_BUILD_TYPE=Debug
+        working-directory: build_dir
+        env:
+          CC: ${{matrix.CC}}
+          CXX: ${{matrix.CXX}}
+
+      - name: cmake build
+        run: cmake --build . --parallel 2
+        working-directory: build_dir
+
+      - name: cmake test
+        run: ctest -j2 -C Debug --output-on-failure
+        working-directory: build_dir

.github/workflows/windows-unit.yml

@@ -0,0 +1,34 @@
+name: Windows unit
+# adapted from: https://github.com/trase-cpp/trase/tree/master/.github/workflows
+on:
+  push:
+    branches:
+      - master
+      #- develop
+  pull_request:
+    branches:
+      - '**'
+
+jobs:
+
+  build-and-test:
+    name: Windows unit
+    runs-on: windows-latest
+
+    steps:
+      - uses: actions/checkout@v3
+
+      - name: make build directory
+        run: mkdir build_dir
+
+      - name: cmake configure
+        run: cmake .. -DCMAKE_BUILD_TYPE=Debug
+        working-directory: build_dir
+
+      - name: cmake build
+        run: cmake --build . --parallel 2
+        working-directory: build_dir
+
+      - name: cmake test
+        run: ctest -j1 -C Debug --verbose --output-on-failure
+        working-directory: build_dir