chore: correct __version__ in hugr.py

hugr-py/src/hugr/__init__.py

@@ -2,7 +2,9 @@
 representation.
 """
 
-__version__ = "0.2.0a1"
+# This is updated by our release-please workflow, triggered by this
+# annotation: x-release-please-version
+__version__ = "0.2.1"
 
 
 def it_works() -> str:

hugr-py/tests/test_version.py

@@ -0,0 +1,16 @@
+# from https://github.com/python-poetry/poetry/issues/144#issuecomment-877835259
+import toml  # type: ignore[import-untyped]
+from pathlib import Path
+import hugr
+
+
+def test_versions_are_in_sync():
+    """Checks if the pyproject.toml and package.__init__.py __version__ are in sync."""
+
+    path = Path(__file__).resolve().parents[1] / "pyproject.toml"
+    pyproject = toml.loads(open(str(path)).read())
+    pyproject_version = pyproject["tool"]["poetry"]["version"]
+
+    package_init_version = hugr.__version__
+
+    assert package_init_version == pyproject_version

pyproject.toml

@@ -16,6 +16,7 @@ pytest = "^8.1.1"
 pytest-cov = "^4.1.0"
 mypy = "^1.9.0"
 ruff = "^0.3.3"
+toml = "^0.10.0"
 
 [tool.poetry.group.hugr.dependencies]
 hugr = { path = "hugr-py", develop = true }