test: add comprehensive test suite for visualization and comparison modules

tests/test_comparison.py

@@ -0,0 +1,63 @@
+"""Tests for src/pygui/backend/comparison.py."""
+
+import numpy as np
+from pygui.backend.comparison import compare_runs
+
+
+def test_identical_series():
+    a = [20.0, 30.0, 40.0, 50.0, 60.0]
+    result = compare_runs(a, a)
+    assert result["distance"] == 0.0
+    assert len(result["index_a"]) == len(a)
+    assert result["index_a"] == result["index_b"]
+
+
+def test_empty_series():
+    result = compare_runs([], [])
+    assert result["distance"] == float("inf")
+    assert result["index_a"] == []
+    assert result["index_b"] == []
+    assert result["warping_path"] == []
+
+
+def test_one_empty():
+    result = compare_runs([10.0, 20.0], [])
+    assert result["distance"] == float("inf")
+
+
+def test_aligned_series():
+    a = [10.0, 20.0, 30.0]
+    b = [15.0, 25.0, 35.0]
+    result = compare_runs(a, b)
+    assert result["distance"] >= 0.0
+    assert len(result["index_a"]) > 0
+    assert len(result["index_b"]) > 0
+
+
+def test_single_element():
+    result = compare_runs([42.0], [42.0])
+    assert result["distance"] == 0.0
+
+
+def test_different_lengths():
+    short = [10.0, 20.0]
+    long_ = [10.0, 15.0, 20.0, 25.0, 30.0]
+    result = compare_runs(short, long_)
+    assert result["distance"] >= 0.0
+    assert len(result["index_a"]) > 0
+    assert len(result["index_b"]) > 0
+    assert len(result["index_a"]) == len(result["index_b"])
+
+
+def test_return_structure():
+    a = [1.0, 2.0, 3.0, 4.0, 5.0]
+    b = [2.0, 3.0, 4.0, 5.0, 6.0]
+    result = compare_runs(a, b)
+    assert "distance" in result
+    assert "index_a" in result
+    assert "index_b" in result
+    assert "warping_path" in result
+    assert isinstance(result["distance"], float)
+    assert isinstance(result["index_a"], list)
+    assert isinstance(result["index_b"], list)
+    assert isinstance(result["warping_path"], list)