diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 2fc8441..527a878 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -18,3 +18,18 @@ jobs:
         run: black --check --line-length 120 pandoc_plantuml_filter.py tests setup.py
       - name: black format check
         run: flake8 --max-line-length 120 pandoc_plantuml_filter.py tests setup.py
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - name: Set up Python 3.11
+        uses: actions/setup-python@v4
+        with:
+          python-version: 3.11
+      - name: Setup build and test environment
+        run: python -m pip install --upgrade pip setuptools wheel pytest pytest-mock
+      - name: Setup package
+        run: python -m pip install .
+      - name: run tests
+        run: pytest
+
diff --git a/tests/test_unit.py b/tests/test_unit.py
new file mode 100644
index 0000000..5a247ea
--- /dev/null
+++ b/tests/test_unit.py
@@ -0,0 +1,18 @@
+import pytest
+
+from pandoc_plantuml_filter import plantuml
+
+
+def test_call_plantuml_create_para_object(mocker):
+    mocker.patch("os.path.isfile", return_value=False)
+    mock = mocker.patch("subprocess.check_call")
+
+    ret = plantuml(
+        key="CodeBlock", value=[["", ["plantuml"], []], ""], format_=None, meta={}
+    )
+
+    assert isinstance(ret, dict)
+    assert "t" in ret.keys()
+    assert ret["t"] == "Para"
+
+    mock.assert_called_once()