Add tests.

tests/test_notes.py

@@ -0,0 +1,57 @@
+"""Tests for notes loading."""
+
+import pytest
+from pathlib import Path
+
+import debian_todo
+
+
+class TestLoadNotes:
+    """Tests for load_notes function."""
+
+    def test_loads_notes_from_file(self, tmp_path, monkeypatch):
+        notes_file = tmp_path / "notes"
+        notes_file.write_text("foo some note\nbar another note\n")
+        monkeypatch.setattr(debian_todo, "NOTES_PATH", notes_file)
+
+        result = debian_todo.load_notes()
+        assert result == {"foo": "some note", "bar": "another note"}
+
+    def test_returns_empty_when_file_missing(self, tmp_path, monkeypatch):
+        notes_file = tmp_path / "notes"
+        monkeypatch.setattr(debian_todo, "NOTES_PATH", notes_file)
+
+        result = debian_todo.load_notes()
+        assert result == {}
+
+    def test_handles_package_without_note(self, tmp_path, monkeypatch):
+        notes_file = tmp_path / "notes"
+        notes_file.write_text("foo\n")
+        monkeypatch.setattr(debian_todo, "NOTES_PATH", notes_file)
+
+        result = debian_todo.load_notes()
+        assert result == {"foo": ""}
+
+    def test_joins_multiple_notes(self, tmp_path, monkeypatch):
+        notes_file = tmp_path / "notes"
+        notes_file.write_text("foo first note\nfoo second note\n")
+        monkeypatch.setattr(debian_todo, "NOTES_PATH", notes_file)
+
+        result = debian_todo.load_notes()
+        assert result == {"foo": "first note; second note"}
+
+    def test_skips_blank_lines(self, tmp_path, monkeypatch):
+        notes_file = tmp_path / "notes"
+        notes_file.write_text("foo note one\n\nbar note two\n\n")
+        monkeypatch.setattr(debian_todo, "NOTES_PATH", notes_file)
+
+        result = debian_todo.load_notes()
+        assert result == {"foo": "note one", "bar": "note two"}
+
+    def test_handles_multiword_notes(self, tmp_path, monkeypatch):
+        notes_file = tmp_path / "notes"
+        notes_file.write_text("foo this is a long note with many words\n")
+        monkeypatch.setattr(debian_todo, "NOTES_PATH", notes_file)
+
+        result = debian_todo.load_notes()
+        assert result == {"foo": "this is a long note with many words"}