(TESTS)[Multi File]: Add unit tests for multi-format spectrum parsing

- Created comprehensive tests for spectrum parsing from TXT, CSV, and JSON file formats.
- Validates correct extraction of wavenumber and intensity values from various data layouts.
- Covers error handling for malformed files, verifies format detection logic, and ensures compatibility with new multi-format upload pipeline.
- Protects against regression and parsing failures as input support expands.

tests/test_multi_format.py

@@ -0,0 +1,218 @@
+"""Tests for multi-format file parsing functionality."""
+
+import pytest
+import numpy as np
+from utils.multifile import (
+    parse_spectrum_data,
+    detect_file_format,
+    parse_json_spectrum,
+    parse_csv_spectrum,
+    parse_txt_spectrum,
+)
+
+
+def test_detect_file_format():
+    """Test automatic file format detection."""
+    # JSON detection
+    json_content = '{"wavenumbers": [1, 2, 3], "intensities": [0.1, 0.2, 0.3]}'
+    assert detect_file_format("test.json", json_content) == "json"
+
+    # CSV detection
+    csv_content = "wavenumber,intensity\n1000,0.5\n1001,0.6"
+    assert detect_file_format("test.csv", csv_content) == "csv"
+
+    # TXT detection (default)
+    txt_content = "1000 0.5\n1001 0.6"
+    assert detect_file_format("test.txt", txt_content) == "txt"
+
+
+def test_parse_json_spectrum():
+    """Test JSON spectrum parsing."""
+    # Test object format
+    json_content = '{"wavenumbers": [1000, 1001, 1002], "intensities": [0.1, 0.2, 0.3]}'
+    x, y = parse_json_spectrum(json_content)
+
+    expected_x = np.array([1000, 1001, 1002])
+    expected_y = np.array([0.1, 0.2, 0.3])
+
+    np.testing.assert_array_equal(x, expected_x)
+    np.testing.assert_array_equal(y, expected_y)
+
+    # Test alternative key names
+    json_content_alt = '{"x": [1000, 1001, 1002], "y": [0.1, 0.2, 0.3]}'
+    x_alt, y_alt = parse_json_spectrum(json_content_alt)
+    np.testing.assert_array_equal(x_alt, expected_x)
+    np.testing.assert_array_equal(y_alt, expected_y)
+
+    # Test array of objects format
+    json_array = """[
+        {"wavenumber": 1000, "intensity": 0.1},
+        {"wavenumber": 1001, "intensity": 0.2},
+        {"wavenumber": 1002, "intensity": 0.3}
+    ]"""
+    x_arr, y_arr = parse_json_spectrum(json_array)
+    np.testing.assert_array_equal(x_arr, expected_x)
+    np.testing.assert_array_equal(y_arr, expected_y)
+
+
+def test_parse_csv_spectrum():
+    """Test CSV spectrum parsing."""
+    # Test with headers
+    csv_with_headers = """wavenumber,intensity
+1000,0.1
+1001,0.2
+1002,0.3
+1003,0.4
+1004,0.5
+1005,0.6
+1006,0.7
+1007,0.8
+1008,0.9
+1009,1.0
+1010,1.1
+1011,1.2"""
+
+    x, y = parse_csv_spectrum(csv_with_headers)
+    expected_x = np.array(
+        [1000, 1001, 1002, 1003, 1004, 1005, 1006, 1007, 1008, 1009, 1010, 1011]
+    )
+    expected_y = np.array([0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2])
+
+    np.testing.assert_array_equal(x, expected_x)
+    np.testing.assert_array_equal(y, expected_y)
+
+    # Test without headers
+    csv_no_headers = """1000,0.1
+1001,0.2
+1002,0.3
+1003,0.4
+1004,0.5
+1005,0.6
+1006,0.7
+1007,0.8
+1008,0.9
+1009,1.0
+1010,1.1
+1011,1.2"""
+
+    x_no_h, y_no_h = parse_csv_spectrum(csv_no_headers)
+    np.testing.assert_array_equal(x_no_h, expected_x)
+    np.testing.assert_array_equal(y_no_h, expected_y)
+
+    # Test semicolon delimiter
+    csv_semicolon = """1000;0.1
+1001;0.2
+1002;0.3
+1003;0.4
+1004;0.5
+1005;0.6
+1006;0.7
+1007;0.8
+1008;0.9
+1009;1.0
+1010;1.1
+1011;1.2"""
+
+    x_semi, y_semi = parse_csv_spectrum(csv_semicolon)
+    np.testing.assert_array_equal(x_semi, expected_x)
+    np.testing.assert_array_equal(y_semi, expected_y)
+
+
+def test_parse_txt_spectrum():
+    """Test TXT spectrum parsing."""
+    txt_content = """# Comment line
+1000 0.1
+1001 0.2
+1002 0.3
+1003 0.4
+1004 0.5
+1005 0.6
+1006 0.7
+1007 0.8
+1008 0.9
+1009 1.0
+1010 1.1
+1011 1.2"""
+
+    x, y = parse_txt_spectrum(txt_content)
+    expected_x = np.array(
+        [1000, 1001, 1002, 1003, 1004, 1005, 1006, 1007, 1008, 1009, 1010, 1011]
+    )
+    expected_y = np.array([0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2])
+
+    np.testing.assert_array_equal(x, expected_x)
+    np.testing.assert_array_equal(y, expected_y)
+
+    # Test comma-separated
+    txt_comma = """1000,0.1
+1001,0.2
+1002,0.3
+1003,0.4
+1004,0.5
+1005,0.6
+1006,0.7
+1007,0.8
+1008,0.9
+1009,1.0
+1010,1.1
+1011,1.2"""
+
+    x_comma, y_comma = parse_txt_spectrum(txt_comma)
+    np.testing.assert_array_equal(x_comma, expected_x)
+    np.testing.assert_array_equal(y_comma, expected_y)
+
+
+def test_parse_spectrum_data_integration():
+    """Test integrated spectrum data parsing with format detection."""
+    # Test automatic format detection and parsing
+    test_cases = [
+        (
+            '{"wavenumbers": [1000, 1001, 1002, 1003, 1004, 1005, 1006, 1007, 1008, 1009, 1010, 1011], "intensities": [0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2]}',
+            "test.json",
+        ),
+        (
+            "wavenumber,intensity\n1000,0.1\n1001,0.2\n1002,0.3\n1003,0.4\n1004,0.5\n1005,0.6\n1006,0.7\n1007,0.8\n1008,0.9\n1009,1.0\n1010,1.1\n1011,1.2",
+            "test.csv",
+        ),
+        (
+            "1000 0.1\n1001 0.2\n1002 0.3\n1003 0.4\n1004 0.5\n1005 0.6\n1006 0.7\n1007 0.8\n1008 0.9\n1009 1.0\n1010 1.1\n1011 1.2",
+            "test.txt",
+        ),
+    ]
+
+    for content, filename in test_cases:
+        x, y = parse_spectrum_data(content, filename)
+        assert len(x) >= 10
+        assert len(y) >= 10
+        assert len(x) == len(y)
+
+
+def test_insufficient_data_points():
+    """Test handling of insufficient data points."""
+    # Test with too few points
+    insufficient_data = "1000 0.1\n1001 0.2"  # Only 2 points, need at least 10
+
+    with pytest.raises(ValueError, match="Insufficient data points"):
+        parse_txt_spectrum(insufficient_data, "test.txt")
+
+
+def test_invalid_json():
+    """Test handling of invalid JSON."""
+    invalid_json = (
+        '{"wavenumbers": [1000, 1001], "intensities": [0.1}'  # Missing closing bracket
+    )
+
+    with pytest.raises(ValueError, match="Invalid JSON format"):
+        parse_json_spectrum(invalid_json)
+
+
+def test_empty_file():
+    """Test handling of empty files."""
+    empty_content = ""
+
+    with pytest.raises(ValueError, match="No data lines found"):
+        parse_txt_spectrum(empty_content, "empty.txt")
+
+
+if __name__ == "__main__":
+    pytest.main([__file__])