add test

Author: tlambert03

src/scyjava/_stubs/_genstubs.py

@@ -69,6 +69,10 @@ def generate_stubs(
         stub generator wrote to it (and therefore inaccurate).
     """
     import jpype
+
+    # FIXME: either remove the _JImportLoader from sys.meta_path after this is done
+    # (if it wasn't there to begin with), or replace the import_module calls below
+    # with a more direct JPackage call
     import jpype.imports
 
     startJVM = jpype.startJVM

tests/test_stubgen.py

@@ -0,0 +1,56 @@
+from __future__ import annotations
+
+import sys
+from typing import TYPE_CHECKING
+from unittest.mock import patch
+
+import jpype
+import jpype.imports
+
+import scyjava
+from scyjava._stubs import _cli
+
+if TYPE_CHECKING:
+    from pathlib import Path
+
+    import pytest
+
+
+def test_stubgen(monkeypatch: pytest.MonkeyPatch, tmp_path: Path) -> None:
+    monkeypatch.setattr(
+        sys,
+        "argv",
+        [
+            "scyjava-stubgen",
+            "org.scijava:parsington:3.1.0",
+            "--output-dir",
+            str(tmp_path),
+        ],
+    )
+    _cli.main()
+
+    # remove the `jpype.imports` magic from the import system if present
+    mp = [x for x in sys.meta_path if not isinstance(x, jpype.imports._JImportLoader)]
+    monkeypatch.setattr(sys, "meta_path", mp)
+
+    # add tmp_path to the import path
+    monkeypatch.setattr(sys, "path", [str(tmp_path)])
+
+    # first cleanup to make sure we are not importing from the cache
+    sys.modules.pop("org", None)
+    sys.modules.pop("org.scijava", None)
+    sys.modules.pop("org.scijava.parsington", None)
+    # make sure the stubgen command works and that we can now impmort stuff
+
+    with patch.object(scyjava._jvm, "start_jvm") as mock_start_jvm:
+        from org.scijava.parsington import Function
+
+        assert Function is not None
+        assert repr(Function) == "<scyjava class 'org.scijava.parsington.Function'>"
+        # ensure that no calls to start_jvm were made
+        mock_start_jvm.assert_not_called()
+
+        # only after instantiating the class should we have a call to start_jvm
+        func = Function(1)
+        mock_start_jvm.assert_called_once()
+        assert isinstance(func, jpype.JObject)