Enforce 100% code coverage in tests (#283)

Author: johnthagen

noxfile.py

@@ -16,7 +16,15 @@ def test(s: Session) -> None:
         f"--python={s.virtualenv.location}",
         env={"UV_PROJECT_ENVIRONMENT": s.virtualenv.location},
     )
-    s.run("pytest", "--cov=fact", "--cov-report=html", "--cov-report=term", "tests", *s.posargs)
+    s.run(
+        "pytest",
+        "--cov=fact",
+        "--cov-report=html",
+        "--cov-report=term",
+        "--cov-fail-under=100",
+        "tests",
+        *s.posargs,
+    )
 
 
 # For some sessions, set venv_backend="none" to simply execute scripts within the existing

src/fact/cli.py

@@ -18,5 +18,5 @@ def main(n: Annotated[int, Argument(min=0, help="The input n of fact(n)")]) -> N
 
 
 # Allow the script to be run standalone (useful during development).
-if __name__ == "__main__":
+if __name__ == "__main__":  # pragma: no branch
     app()

tests/test_cli.py

@@ -0,0 +1,16 @@
+import subprocess
+
+
+def test_main() -> None:
+    """Test the main function of the CLI."""
+
+    # Run the CLI command
+    result = subprocess.run(
+        ["python", "-m", "fact.cli", "5"],
+        capture_output=True,
+        text=True,
+    )
+
+    # Check the output
+    assert result.returncode == 0
+    assert "fact(5) = 120" in result.stdout