DEVX-14: feat: fix molecule platforms to use sleep infinity, add --platforms-file

tests/unit/test_platforms.py

@@ -1,11 +1,13 @@
-"""Unit tests for scripts/ci/platforms.py."""
+"""Unit tests for devx.molecule.platforms."""
 
-from devx.molecule.platforms import PLATFORMS
+import json
+
+from devx.molecule.platforms import PLATFORMS, load_platforms
 
 
 class TestPlatforms:
     def test_platforms_not_empty(self) -> None:
-        assert len(PLATFORMS) >= 4
+        assert len(PLATFORMS) >= 1
 
     def test_each_platform_has_required_keys(self) -> None:
         for p in PLATFORMS:
@@ -17,9 +19,40 @@ class TestPlatforms:
         names = [p["name"] for p in PLATFORMS]
         assert len(names) == len(set(names))
 
+    def test_platforms_use_sleep_infinity(self) -> None:
+        """All default platforms must use sleep infinity, not systemd."""
+        for p in PLATFORMS:
+            assert p["command"] == "sleep infinity", f"Platform {p['name']} uses {p['command']}"
+
     def test_known_platforms_present(self) -> None:
         names = {p["name"] for p in PLATFORMS}
-        assert "ubuntu-2204" in names
-        assert "ubuntu-2404" in names
-        assert "debian-12" in names
-        assert "archlinux" in names
+        assert "ubuntu-2604" in names
+
+
+class TestLoadPlatforms:
+    def test_load_platforms_default(self, tmp_path) -> None:  # type: ignore[no-untyped-def]
+        """load_platforms with no file returns PLATFORMS."""
+        result = load_platforms(None)
+        assert result == PLATFORMS
+
+    def test_load_platforms_from_file(self, tmp_path) -> None:  # type: ignore[no-untyped-def]
+        """load_platforms reads custom platforms from JSON file."""
+        custom = [
+            {"name": "custom-os", "image": "custom:latest", "command": "sleep infinity"},
+        ]
+        f = tmp_path / "platforms.json"
+        f.write_text(json.dumps(custom))
+        result = load_platforms(f)
+        assert result == custom
+
+    def test_load_platforms_missing_file_falls_back(self, tmp_path) -> None:  # type: ignore[no-untyped-def]
+        """load_platforms falls back to PLATFORMS when file doesn't exist."""
+        result = load_platforms(tmp_path / "nonexistent.json")
+        assert result == PLATFORMS
+
+    def test_load_platforms_empty_list_falls_back(self, tmp_path) -> None:  # type: ignore[no-untyped-def]
+        """load_platforms falls back to PLATFORMS when file has empty list."""
+        f = tmp_path / "platforms.json"
+        f.write_text("[]")
+        result = load_platforms(f)
+        assert result == PLATFORMS