ci: Define test for 'age version'

tests/conftest.py

@@ -0,0 +1,18 @@
+"""Common test contexts."""
+
+from pathlib import Path
+
+import pytest
+
+
+@pytest.fixture
+def root() -> Path:
+    """Path-object of project root."""
+    return Path(__file__).parent.parent
+
+
+@pytest.fixture
+def target_bin(root: Path) -> str:
+    """Full-path of binary generated by ``cargo build``."""
+    bin_path = root / "target" / "debug" / "age"
+    return str(bin_path.resolve())

tests/test_version.py

@@ -0,0 +1,12 @@
+"""Test case for ``age version``."""
+
+import tomllib
+from pathlib import Path
+from subprocess import PIPE, run
+
+
+def test_it(root: Path, target_bin: str):  # noqa: D103
+    cargo = tomllib.loads((root / "Cargo.toml").read_text())
+    proc = run([target_bin, "version"], stdout=PIPE, stderr=PIPE, text=True)
+    assert proc.returncode == 0
+    assert f"v{cargo['package']['version']}" in proc.stdout