major refactor (untested)

tests/test_error_rate_plot.py

@@ -0,0 +1,38 @@
+import os
+import pytest
+from unittest.mock import patch, mock_open
+from archive.test_errorrate_runner import generate_error_rate_plot
+
+@pytest.fixture
+def mock_data_dir(tmp_path):
+    """Fixture to create a temporary data directory."""
+    data_dir = tmp_path / "data"
+    data_dir.mkdir()
+    return data_dir
+
+@patch("builtins.open", new_callable=mock_open, read_data="{}")
+@patch("os.path.exists", return_value=True)
+def test_generate_error_rate_plot_no_data(mock_exists, mock_open, mock_data_dir):
+    """Test generate_error_rate_plot with no data."""
+    plot_path, summary = generate_error_rate_plot(str(mock_data_dir / "applications.json"))
+    assert plot_path is None
+    assert summary == ""
+
+@patch("builtins.open", new_callable=mock_open)
+@patch("os.path.exists", return_value=True)
+@patch("matplotlib.pyplot.savefig")
+def test_generate_error_rate_plot_with_data(mock_savefig, mock_exists, mock_open, mock_data_dir):
+    """Test generate_error_rate_plot with valid data."""
+    mock_open.return_value.read.return_value = """
+    {
+        "1": {"timestamp": "2025-12-25T12:00:00", "company": "CompanyA", "success": true},
+        "2": {"timestamp": "2025-12-26T12:00:00", "company": "CompanyB", "success": false}
+    }
+    """
+    plot_path, summary = generate_error_rate_plot(str(mock_data_dir / "applications.json"))
+    assert plot_path is not None
+    assert "Total attempts" in summary
+    assert "Successes" in summary
+    assert "Failures" in summary
+    assert "Overall error rate" in summary
+    mock_savefig.assert_called_once()