add function for getting info about installed tape

tests/fixtures.py

@@ -3,6 +3,8 @@ from typing import Callable
 
 import pytest
 
+from labeler.domain.objects import Dimension, MediaDefinition
+
 
 @pytest.fixture
 def current_dir(request) -> str:
@@ -23,3 +25,24 @@ def save_test_image(current_dir) -> Callable[[str, bytes], None]:
         open(os.path.join(current_dir, "test_images", name), "wb").write(data)
 
     return f
+
+
+@pytest.fixture
+def create_test_media() -> Callable[[int, int, int, int, int], MediaDefinition]:
+    def f(
+        width: int,
+        height: int,
+        dpi: int = 600,
+        margin_horizontal: int = 0,
+        margin_vertical: int = 0,
+    ):
+        return MediaDefinition(
+            width=Dimension(mm=width),
+            length=Dimension(mm=height),
+            minimal_margin_horizontal=Dimension(mm=margin_horizontal),
+            minimal_margin_vertical=Dimension(mm=margin_vertical),
+            dpi=dpi,
+            description=f"test media {width}mm x{height}mm @ {dpi}dpi",
+        )
+
+    return f