Initial commit

tests/test_alpha5.py

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+"""Tests for the ALPHA-5 NORAD catalog-number encoding."""
+
+from __future__ import annotations
+
+import pytest
+from sgp4.api import Satrec
+
+from odm import (
+    ALPHA5_MAX,
+    ALPHA5_MIN,
+    from_alpha5,
+    tle_catalog_field,
+    to_alpha5,
+)
+from odm import parse_tle, tle_from_gp
+
+
+@pytest.mark.parametrize("value,expected", [
+    (100000, "A0000"),
+    (108493, "A8493"),
+    (180000, "J0000"),   # skips I
+    (234567, "P4567"),
+    (270354, "T0354"),
+    (339999, "Z9999"),
+])
+def test_to_alpha5_known_values(value, expected):
+    assert to_alpha5(value) == expected
+
+
+def test_to_alpha5_skips_i_and_o():
+    encoded = "".join(to_alpha5(v * 10000)[0] for v in range(10, 34))
+    assert "I" not in encoded and "O" not in encoded
+    assert len(set(encoded)) == 24  # all distinct
+
+
+@pytest.mark.parametrize("value", [ALPHA5_MIN, 123456, 234567, ALPHA5_MAX])
+def test_alpha5_round_trips(value):
+    assert from_alpha5(to_alpha5(value)) == value
+
+
+@pytest.mark.parametrize("value", [99999, ALPHA5_MAX + 1, 0, -1])
+def test_to_alpha5_rejects_out_of_range(value):
+    with pytest.raises(ValueError):
+        to_alpha5(value)
+
+
+@pytest.mark.parametrize("field", ["", "ABCDE", "A123", "I0000", "O0000", "12345"])
+def test_from_alpha5_rejects_invalid(field):
+    assert from_alpha5(field) is None
+
+
+def test_tle_catalog_field_plain_numeric_unchanged():
+    assert tle_catalog_field("25544", alpha5=True) == "25544"
+    assert tle_catalog_field("25544", alpha5=False) == "25544"
+
+
+def test_tle_catalog_field_alpha5_vs_temp():
+    assert tle_catalog_field("234567", alpha5=True) == "P4567"
+    temp = tle_catalog_field("234567", alpha5=False)
+    assert temp.isdigit() and 90000 <= int(temp) <= 99999
+
+
+def test_tle_catalog_field_alphanumeric_always_pseudo():
+    for flag in (True, False):
+        field = tle_catalog_field("A1234", alpha5=flag)
+        assert field.isdigit() and 90000 <= int(field) <= 99999
+
+
+def test_tle_from_gp_alpha5_round_trips_through_sgp4():
+    iss = parse_tle(
+        "ISS (ZARYA)",
+        "1 25544U 98067A   24070.50000000  .00012345  00000-0  22000-3 0  9991",
+        "2 25544  51.6400 200.0000 0001234  90.0000 270.0000 15.50000000400000",
+    )
+    gp = dict(iss.omm)
+    gp["NORAD_CAT_ID"] = "234567"
+    _, line1, line2 = tle_from_gp(gp, alpha5=True)
+
+    assert len(line1) == 69 and len(line2) == 69
+    assert line1[2:7] == "P4567"
+    assert line1[2:7] == line2[2:7]
+    # sgp4 must decode the ALPHA-5 field back to the real catalog number.
+    sat = Satrec.twoline2rv(line1, line2)
+    assert sat.satnum == 234567
+
+
+def test_tle_from_gp_defaults_to_temp_id():
+    """Without alpha5, a 6-digit numeric ID must not overflow the 5-char field."""
+    iss = parse_tle(
+        "ISS (ZARYA)",
+        "1 25544U 98067A   24070.50000000  .00012345  00000-0  22000-3 0  9991",
+        "2 25544  51.6400 200.0000 0001234  90.0000 270.0000 15.50000000400000",
+    )
+    gp = dict(iss.omm)
+    gp["NORAD_CAT_ID"] = "234567"
+    _, line1, line2 = tle_from_gp(gp)
+    assert len(line1) == 69 and line1[2:7].isdigit()
+    assert 90000 <= int(line1[2:7]) <= 99999