Add tests for output.Output and output.File

tests/unit/test_file.py

@@ -0,0 +1,29 @@
+from pathlib import Path
+from omicron.ssg.output.file import File
+
+
+def test_write_copies_content(thin_site, tmp_path):
+    source = tmp_path / "source.txt"
+    source.write_text("hello")
+    dest_dir = thin_site.output_path / "assets"
+    dest_dir.mkdir(parents=True)
+
+    file = File(thin_site, Path("assets/copy.txt"), source)
+    file.write()
+
+    dest = dest_dir / "copy.txt"
+    assert dest.read_text() == "hello"
+
+
+def test_write_overwrites_existing_destination(thin_site, tmp_path):
+    dest = thin_site.output_path / "copy.txt"
+    dest.parent.mkdir(parents=True, exist_ok=True)
+    dest.write_text("old")
+
+    source = tmp_path / "source.txt"
+    source.write_text("new")
+
+    file = File(thin_site, Path("copy.txt"), source)
+    file.write()
+
+    assert dest.read_text() == "new"