TEST: Updated tests for extend_command

Signed-off-by: Gagandeep Singh <gdp.1807@gmail.com>

Author: czgdp1807

spin/tests/test_extend_command.py

@@ -28,6 +28,7 @@ def build_ext(*, parent_callback, extra=None, **kwargs):
 
     assert "Additional docstring" in get_usage(build_ext)
     assert "Additional docstring" not in get_usage(cmds.meson.build)
+    assert get_usage(cmds.meson.build) not in get_usage(build_ext)
 
     @extend_command(cmds.meson.build, doc="Hello world")
     def build_ext(*, parent_callback, extra=None, **kwargs):
@@ -39,6 +40,7 @@ def build_ext(*, parent_callback, extra=None, **kwargs):
     doc = get_usage(build_ext)
     assert "Hello world\n" in doc
     assert "\n  Additional docstring" in doc
+    assert get_usage(cmds.meson.build) not in get_usage(build_ext)
 
 
 def test_ext_additional_args():