fix: redeploy the site on any script it imports

tests/test_workflow_paths.py

@@ -0,0 +1,89 @@
+"""The site redeploys whenever a script it runs changes.
+
+Deploy Site listed five scripts by hand while the build imports forty:
+a change to siterender.py, which writes every page, published nothing
+until some unrelated file moved.
+"""
+
+from __future__ import annotations
+
+import ast
+import fnmatch
+import unittest
+from pathlib import Path
+
+import yaml
+
+REPO_ROOT = Path(__file__).resolve().parent.parent
+SCRIPTS = REPO_ROOT / "scripts"
+
+
+def _module_file(name: str) -> Path | None:
+    name = name.removeprefix("scripts.")
+    for candidate in (
+        SCRIPTS / (name.replace(".", "/") + ".py"),
+        SCRIPTS / name.replace(".", "/") / "__init__.py",
+    ):
+        if candidate.exists():
+            return candidate
+    return None
+
+
+def _imports(path: Path) -> set[Path]:
+    found: set[Path] = set()
+    for node in ast.walk(ast.parse(path.read_text(encoding="utf-8"))):
+        if isinstance(node, ast.Import):
+            names = [alias.name for alias in node.names]
+        elif isinstance(node, ast.ImportFrom) and node.level == 0 and node.module:
+            names = [node.module, *(f"{node.module}.{a.name}" for a in node.names)]
+        elif isinstance(node, ast.ImportFrom):
+            base = path.parent / (node.module or "").replace(".", "/")
+            candidates = [base / f"{a.name}.py" for a in node.names]
+            candidates += [base.with_suffix(".py"), base / "__init__.py"]
+            found.update(c for c in candidates if c.is_file())
+            continue
+        else:
+            continue
+        found.update(f for f in map(_module_file, names) if f)
+    return found
+
+
+def closure(entry_points: list[str]) -> set[str]:
+    seen: set[Path] = set()
+    stack = [SCRIPTS / name for name in entry_points]
+    while stack:
+        path = stack.pop()
+        if path not in seen:
+            seen.add(path)
+            stack.extend(_imports(path))
+    return {str(p.relative_to(REPO_ROOT)) for p in seen}
+
+
+class DeploySiteTriggers(unittest.TestCase):
+    def test_every_script_the_build_imports_triggers_it(self):
+        workflow = yaml.safe_load(
+            (REPO_ROOT / ".github/workflows/deploy-site.yml").read_text(encoding="utf-8")
+        )
+        on = workflow.get("on", workflow.get(True))
+        patterns = on["push"]["paths"]
+        run = "\n".join(
+            step.get("run", "") for job in workflow["jobs"].values() for step in job["steps"]
+        )
+        entry_points = sorted(
+            {
+                word.removeprefix("scripts/")
+                for word in run.split()
+                if word.startswith("scripts/") and word.endswith(".py")
+            }
+        )
+        self.assertIn("generate_site.py", entry_points)
+        uncovered = sorted(
+            path
+            for path in closure(entry_points)
+            if not any(fnmatch.fnmatch(path, p.replace("**", "*")) for p in patterns)
+        )
+        self.assertEqual(uncovered, [])
+
+
+if __name__ == "__main__":
+    unittest.main()