test(readme): add test for the example in the readme

README.md

@@ -40,6 +40,7 @@ pip install -e .
 ## :crown: Workflow example
 
 Let's consider a parallelized Monte Carlo simulation of the [Ishigami function](https://www.sfu.ca/~ssurjano/ishigami.html):
+<!---example marker, do not remove this comment-->
 ```python
 from queens.distributions import BetaDistribution, NormalDistribution, UniformDistribution
 from queens.drivers import FunctionDriver
@@ -80,6 +81,7 @@ if __name__ == "__main__":
     # Start QUEENS run
     run_iterator(iterator, global_settings=global_settings)
 ```
+<!---example marker, do not remove this comment-->
 
 <div align="center">
 <img src="readme_images/monte_carlo_uq.png" alt="QUEENS logo" width="500"/>

test_utils/get_example_in_read_me.py

@@ -0,0 +1,45 @@
+#
+# SPDX-License-Identifier: LGPL-3.0-or-later
+# Copyright (c) 2024, QUEENS contributors.
+#
+# This file is part of QUEENS.
+#
+# QUEENS is free software: you can redistribute it and/or modify it under the terms of the GNU
+# Lesser General Public License as published by the Free Software Foundation, either version 3 of
+# the License, or (at your option) any later version. QUEENS is distributed in the hope that it will
+# be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+# FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You
+# should have received a copy of the GNU Lesser General Public License along with QUEENS. If not,
+# see <https://www.gnu.org/licenses/>.
+#
+"""Extract QUEENS example from the readme."""
+
+from pathlib import Path
+
+EXAMPLE_MARKER = "<!---example marker, do not remove this comment-->"
+
+
+def get_queens_example_from_readme(output_dir):
+    """Extract the example from the readme.
+
+    Args:
+        output_dir (str): Output directory for the QUEENS run.
+    """
+    readme_path = Path(__file__).parents[1] / "README.md"
+
+    # Split the example in the readme using the marker
+    text = readme_path.read_text().split(EXAMPLE_MARKER)
+
+    # Only one example should appear
+    if len(text) != 3:
+        raise ValueError("Could not extract the example from the readme!")
+
+    # Extract the source
+    example_source = (
+        text[1]
+        .replace("```python", "")
+        .replace("```", "")
+        .replace('output_dir="."', f'output_dir="{output_dir}"')
+    )
+
+    return example_source

tests/integration_tests/python/test_readme_example.py

@@ -0,0 +1,32 @@
+#
+# SPDX-License-Identifier: LGPL-3.0-or-later
+# Copyright (c) 2024, QUEENS contributors.
+#
+# This file is part of QUEENS.
+#
+# QUEENS is free software: you can redistribute it and/or modify it under the terms of the GNU
+# Lesser General Public License as published by the Free Software Foundation, either version 3 of
+# the License, or (at your option) any later version. QUEENS is distributed in the hope that it will
+# be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+# FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You
+# should have received a copy of the GNU Lesser General Public License along with QUEENS. If not,
+# see <https://www.gnu.org/licenses/>.
+#
+"""Test the readme QUEENS example."""
+
+from queens.utils.run_subprocess import run_subprocess
+from test_utils.get_example_in_read_me import get_queens_example_from_readme
+
+
+def test_queens_readme_example(tmp_path):
+    """Test if the example in the readme runs."""
+    # Get the source of the example
+    example_source = get_queens_example_from_readme(tmp_path)
+
+    # Run the script
+    process_returncode, _, _, _ = run_subprocess(
+        f"python -c '{example_source}'", raise_error_on_subprocess_failure=False
+    )
+
+    # Check for an exit code
+    assert not process_returncode