Add tests.

tests/test_filter.py

@@ -0,0 +1,117 @@
+"""Tests for TODO list filtering functions."""
+
+import pytest
+
+from debian_todo import filter_todo_list, summarize_sources
+
+
+class TestFilterTodoList:
+    """Tests for filter_todo_list function."""
+
+    def test_filters_non_upstream_items(self):
+        todo_list = [
+            {":shortname": "newupstream_foo", ":details": "1.0.0", ":source": "foo"},
+            {":shortname": "rc_bug", ":details": "bug info", ":source": "bar"},
+            {":shortname": "other_type", ":details": "other", ":source": "baz"},
+        ]
+        result = filter_todo_list(todo_list)
+        assert len(result) == 1
+        assert result[0][":source"] == "foo"
+
+    def test_filters_prerelease_by_default(self):
+        todo_list = [
+            {":shortname": "newupstream_foo", ":details": "1.0.0", ":source": "foo"},
+            {":shortname": "newupstream_bar", ":details": "2.0.0rc1", ":source": "bar"},
+        ]
+        result = filter_todo_list(todo_list)
+        assert len(result) == 1
+        assert result[0][":source"] == "foo"
+
+    def test_includes_prerelease_when_requested(self):
+        todo_list = [
+            {":shortname": "newupstream_foo", ":details": "1.0.0", ":source": "foo"},
+            {":shortname": "newupstream_bar", ":details": "2.0.0rc1", ":source": "bar"},
+        ]
+        result = filter_todo_list(todo_list, include_prerelease=True)
+        assert len(result) == 2
+
+    def test_filters_matching_versions(self):
+        # When normalized versions match, the item should be filtered out
+        todo_list = [
+            {
+                ":shortname": "newupstream_foo",
+                ":details": "1.0.0 (currently in unstable: 1.0.0-1)",
+                ":source": "foo",
+            },
+        ]
+        result = filter_todo_list(todo_list)
+        assert len(result) == 0
+
+    def test_keeps_different_versions(self):
+        todo_list = [
+            {
+                ":shortname": "newupstream_foo",
+                ":details": "1.1.0 (currently in unstable: 1.0.0-1)",
+                ":source": "foo",
+            },
+        ]
+        result = filter_todo_list(todo_list)
+        assert len(result) == 1
+
+    def test_handles_epoch_in_current(self):
+        # Epoch should be stripped for comparison
+        todo_list = [
+            {
+                ":shortname": "newupstream_foo",
+                ":details": "1.0.0 (currently in unstable: 1:1.0.0-1)",
+                ":source": "foo",
+            },
+        ]
+        result = filter_todo_list(todo_list)
+        assert len(result) == 0
+
+    def test_skips_invalid_items(self):
+        todo_list = [
+            {":shortname": "newupstream_foo", ":source": "foo"},  # missing :details
+            {":details": "1.0.0", ":source": "bar"},  # missing :shortname
+            {":shortname": 123, ":details": "1.0.0", ":source": "baz"},  # wrong type
+        ]
+        result = filter_todo_list(todo_list)
+        assert len(result) == 0
+
+    def test_empty_list(self):
+        assert filter_todo_list([]) == []
+
+
+class TestSummarizeSources:
+    """Tests for summarize_sources function."""
+
+    def test_extracts_sources(self):
+        todo_list = [
+            {":source": "foo", ":shortname": "newupstream_foo"},
+            {":source": "bar", ":shortname": "newupstream_bar"},
+            {":source": "baz", ":shortname": "rc_bug"},
+        ]
+        result = summarize_sources(todo_list)
+        assert result == {"foo", "bar", "baz"}
+
+    def test_deduplicates_sources(self):
+        todo_list = [
+            {":source": "foo", ":shortname": "type1"},
+            {":source": "foo", ":shortname": "type2"},
+        ]
+        result = summarize_sources(todo_list)
+        assert result == {"foo"}
+
+    def test_skips_non_string_sources(self):
+        todo_list = [
+            {":source": "foo"},
+            {":source": 123},
+            {":source": None},
+            {},
+        ]
+        result = summarize_sources(todo_list)
+        assert result == {"foo"}
+
+    def test_empty_list(self):
+        assert summarize_sources([]) == set()