First commit

part2-logstats/tests/test_parser.py

@@ -0,0 +1,35 @@
+from logstats.parser import count_levels, top_levels
+
+
+def test_count_levels_basic():
+    lines = [
+        "2024-03-01 09:00:00 INFO service started",
+        "2024-03-01 09:00:04 ERROR payment gateway timeout",
+    ]
+    assert count_levels(lines) == {"INFO": 1, "ERROR": 1}
+
+
+def test_count_levels_is_fresh_between_calls():
+    count_levels(["2024-03-01 09:00:00 INFO service started"])
+    second = count_levels(["2024-03-01 09:00:04 ERROR payment gateway timeout"])
+    assert second == {"ERROR": 1}
+
+
+def test_level_is_taken_from_level_field_not_message():
+    lines = ["2024-03-01 09:00:06 INFO user saw ERROR dialog on checkout"]
+    assert count_levels(lines) == {"INFO": 1}
+
+
+def test_ignores_lines_without_a_level_field():
+    lines = ["", "-- rotated --", "2024-03-01 09:00:00"]
+    assert count_levels(lines) == {}
+
+
+def test_top_levels_returns_n_entries():
+    counts = {"INFO": 5, "ERROR": 3, "DEBUG": 1}
+    assert top_levels(counts, 2) == [("INFO", 5), ("ERROR", 3)]
+
+
+def test_top_levels_breaks_ties_alphabetically():
+    counts = {"WARNING": 2, "ERROR": 2, "INFO": 7}
+    assert top_levels(counts, 3) == [("INFO", 7), ("ERROR", 2), ("WARNING", 2)]