Skip tests failing on windows due to lacking environment

pyproject.toml

@@ -41,7 +41,7 @@ typeguard = "^4.1.5"
 typing-extensions = "^4.9.0"
 
 [tool.pytest.ini_options]
-addopts = "--cov --cov-report=term --cov-report=html --cov-branch"
+addopts = "--cov --cov-report=term --cov-report=html --cov-branch --doctest-modules"
 filterwarnings = [
   "error",
   "ignore:.*imghdr.*:DeprecationWarning:mediafile",

test/cli_test.py

@@ -2,6 +2,7 @@
 import os.path
 import platform
 import shutil
+import sys
 from pathlib import Path
 from time import sleep
 
@@ -340,6 +341,9 @@ def test_unkown_collection(self):
             self.runcli("alt", "update", "unkown")
         assert str(e.value) == "Alternative collection 'unkown' not found."
 
+    @pytest.mark.skipif(
+        sys.platform.startswith("win"), reason="Image conversion not available"
+    )
     def test_embed_art(self, tmp_path: Path):
         """Test that artwork is embedded and updated to match the source file.
 

test/helper.py

@@ -29,20 +29,23 @@
 
 @contextmanager
 def capture_stdout():
-    """Save stdout in a StringIO.
+    r"""Collect stdout in a StringIO while still outputting it.
 
     >>> with capture_stdout() as output:
     ...     print('spam')
     ...
+    spam
     >>> output.getvalue()
-    'spam'
+    'spam\n'
     """
     org = sys.stdout
-    sys.stdout = StringIO()
+    buffer = StringIO()
+    sys.stdout = buffer
     try:
         yield sys.stdout
     finally:
         sys.stdout = org
+        sys.stdout.write(buffer.getvalue())
 
 
 @contextmanager