Improve tests.

Author: vnmabus

lazy_loader/tests/test_lazy_loader_magic.py

@@ -0,0 +1,75 @@
+import importlib
+import sys
+import types
+
+import lazy_loader as lazy
+import pytest
+
+
+def test_lazy_import_basics():
+    with lazy.lazy_imports():
+        import math
+
+    with pytest.raises(ImportError):
+        with lazy.lazy_imports():
+            import anything_not_real
+
+    # Now test that accessing attributes does what it should
+    assert math.sin(math.pi) == pytest.approx(0, 1e-6)
+
+
+def test_lazy_import_subpackages():
+    with lazy.lazy_imports():
+        import html.parser as hp
+    assert "html" in sys.modules
+    assert type(sys.modules["html"]) == type(pytest)
+    assert isinstance(hp, importlib.util._LazyModule)
+    assert "html.parser" in sys.modules
+    assert sys.modules["html.parser"] == hp
+
+
+def test_lazy_import_impact_on_sys_modules():
+    with lazy.lazy_imports():
+        import math
+
+    with pytest.raises(ImportError):
+        with lazy.lazy_imports():
+            import anything_not_real
+
+    assert isinstance(math, types.ModuleType)
+    assert "math" in sys.modules
+    assert "anything_not_real" not in sys.modules
+
+    # only do this if numpy is installed
+    pytest.importorskip("numpy")
+    with lazy.lazy_imports():
+        import numpy as np
+    assert isinstance(np, types.ModuleType)
+    assert "numpy" in sys.modules
+
+    np.pi  # trigger load of numpy
+
+    assert isinstance(np, types.ModuleType)
+    assert "numpy" in sys.modules
+
+
+def test_lazy_import_nonbuiltins():
+    with lazy.lazy_imports():
+        import numpy as np
+        import scipy as sp
+
+    assert np.sin(np.pi) == pytest.approx(0, 1e-6)
+
+
+def test_attach_same_module_and_attr_name():
+    from lazy_loader.tests import fake_pkg_magic
+
+    # Grab attribute twice, to ensure that importing it does not
+    # override function by module
+    assert isinstance(fake_pkg_magic.some_func, types.FunctionType)
+    assert isinstance(fake_pkg_magic.some_func, types.FunctionType)
+
+    # Ensure imports from submodule still work
+    from lazy_loader.tests.fake_pkg_magic.some_func import some_func
+
+    assert isinstance(some_func, types.FunctionType)