test(compat): only test platform-specific compat results to each plat…

…form.

Signed-off-by: Braden Mars <bradenmars@bradenmars.me>

tests/test_compat.py

@@ -1,20 +1,26 @@
-# -*- coding: utf-8 -*-
-
 """Compat module unit tests."""
 
+import os
+import sys
+from pathlib import Path
+
 import pytest
 from pytest_mock import MockFixture
-import sys
-import os
 
 from pydngconverter import compat
 
 platform_params = ["Linux", "Windows", "Darwin"]
 
 
-@pytest.fixture(params=platform_params)
+@pytest.fixture(
+    params=[
+        pytest.param(
+            p, marks=pytest.mark.skipif(compat.platform.system() != p, reason=f"{p} only.")
+        )
+        for p in platform_params
+    ]
+)
 def mock_platform(request: pytest.FixtureRequest, mocker: MockFixture):
-    mocker.patch.object(compat.platform, "system", return_value=request.param)
     return request.param
 
 
@@ -61,18 +67,15 @@ async def test_get_compat_path(mocker: MockFixture, platform_paths):
 def test_resolve_executable(mocker: MockFixture, platform_apps):
     platform, expect_path = platform_apps
     mocker.patch("pydngconverter.compat.Path.exists", return_value=True)
-    if platform == "Windows" and not sys.platform.startswith("win"):
-        pytest.skip("skipping windows-only test")
     ret_path = compat.resolve_executable(["ExampleApp"])
     assert str(ret_path) == str(expect_path)
 
 
 def test_resolve_executable_override(mocker):
     mocker.patch("pydngconverter.compat.Path.exists", return_value=True)
-    os.environ["PYDNG_TEST_KEY"] = "/some/fake/path_exec"
-    assert (
-        str(compat.resolve_executable(["path_exec"], env_override="PYDNG_TEST_KEY"))
-        == "/some/fake/path_exec"
+    os.environ["PYDNG_TEST_KEY"] = str(Path("/some/fake/path_exec"))
+    assert Path(compat.resolve_executable(["path_exec"], env_override="PYDNG_TEST_KEY")) == Path(
+        "/some/fake/path_exec"
     )