moved infer_freq_robust to vtools.data.index and added tests.

Author: Eli

tests/test_indexing.py

@@ -0,0 +1,192 @@
+from __future__ import annotations
+
+import pandas as pd
+import numpy as np
+import pytest
+
+from vtools.data.indexing import (
+    resolve_common_freq,
+    regular_index_from_valid_extent,
+    reindex_to_continuous,
+    inferred_regular_freq,
+    compare_regular_freq,
+)
+
+
+def test_resolve_common_freq_same():
+    i1 = pd.date_range("2024-01-01", periods=5, freq="D")
+    i2 = pd.date_range("2024-02-01", periods=3, freq="D")
+    f = resolve_common_freq([i1, i2], preserve_freq=True)
+    assert f == i1.freq
+
+
+def test_resolve_common_freq_none_when_preserve_false():
+    i1 = pd.date_range("2024-01-01", periods=5, freq="D")
+    i2 = pd.date_range("2024-02-01", periods=3, freq="2D")
+    assert resolve_common_freq([i1, i2], preserve_freq=False) is None
+
+
+def test_resolve_common_freq_raises_on_mismatch():
+    i1 = pd.date_range("2024-01-01", periods=5, freq="D")
+    i2 = pd.date_range("2024-02-01", periods=3, freq="2D")
+    with pytest.raises(ValueError, match="inconsistent frequencies"):
+        resolve_common_freq([i1, i2], preserve_freq=True)
+
+
+def test_regular_index_from_valid_extent_series():
+    idx1 = pd.date_range("2024-01-01", periods=5, freq="D")
+    idx2 = pd.date_range("2024-01-03", periods=5, freq="D")
+    s1 = pd.Series([np.nan, 1.0, 2.0, 3.0, np.nan], index=idx1)
+    s2 = pd.Series([10.0, 11.0, 12.0, 13.0, np.nan], index=idx2)
+
+    out = regular_index_from_valid_extent([s1, s2], idx1.freq)
+    expected = pd.date_range("2024-01-02", "2024-01-06", freq="D")
+    pd.testing.assert_index_equal(out, expected)
+
+
+def test_regular_index_from_valid_extent_empty_valid_returns_empty_like_first():
+    idx = pd.date_range("2024-01-01", periods=3, freq="D")
+    s1 = pd.Series([np.nan, np.nan, np.nan], index=idx)
+    s2 = pd.Series([np.nan, np.nan, np.nan], index=idx)
+
+    out = regular_index_from_valid_extent([s1, s2], idx.freq)
+    assert len(out) == 0
+    assert isinstance(out, pd.DatetimeIndex)
+
+
+def test_reindex_to_continuous_regularizes_when_aligned():
+    idx = pd.to_datetime(["2024-01-01", "2024-01-03"])
+    s = pd.Series([1.0, 3.0], index=idx, name="x")
+
+    out = reindex_to_continuous(s, pd.tseries.frequencies.to_offset("D"))
+    expected = pd.Series(
+        [1.0, np.nan, 3.0],
+        index=pd.date_range("2024-01-01", periods=3, freq="D"),
+        name="x",
+    )
+    pd.testing.assert_series_equal(out, expected)
+
+
+def test_reindex_to_continuous_returns_original_when_misaligned():
+    idx = pd.to_datetime(["2024-01-01 00:00", "2024-01-01 00:10", "2024-01-01 00:15"])
+    s = pd.Series([1.0, 2.0, 3.0], index=idx, name="x")
+
+    out = reindex_to_continuous(s, pd.tseries.frequencies.to_offset("15min"))
+    pd.testing.assert_series_equal(out, s)
+
+
+def test_inferred_regular_freq_datetime_ok():
+    idx = pd.date_range("2024-01-01", periods=5, freq="D")
+    s = pd.Series(range(5), index=idx)
+    freq, reason = inferred_regular_freq(s)
+    assert reason == "ok"
+    assert freq == idx.freq
+
+
+def test_inferred_regular_freq_non_datetime():
+    s = pd.Series([1, 2, 3], index=[1, 2, 3])
+    freq, reason = inferred_regular_freq(s)
+    assert freq is None
+    assert reason == "not_datetime_like"
+
+
+def test_inferred_regular_freq_not_monotonic():
+    idx = pd.to_datetime(["2024-01-02", "2024-01-01", "2024-01-03"])
+    s = pd.Series([1, 2, 3], index=idx)
+    freq, reason = inferred_regular_freq(s)
+    assert freq is None
+    assert reason == "not_monotonic"
+
+
+def test_inferred_regular_freq_duplicates():
+    idx = pd.to_datetime(["2024-01-01", "2024-01-01", "2024-01-02"])
+    s = pd.Series([1, 2, 3], index=idx)
+    freq, reason = inferred_regular_freq(s)
+    assert freq is None
+    assert reason == "duplicates"
+
+
+def test_inferred_regular_freq_irregular_infer_failed():
+    idx = pd.to_datetime(["2024-01-01", "2024-01-02", "2024-01-04"])
+    s = pd.Series([1, 2, 3], index=idx)
+    freq, reason = inferred_regular_freq(s)
+    assert freq is None
+    assert reason == "infer_failed"
+
+
+def test_inferred_regular_freq_single_point_degenerate():
+    idx = pd.date_range("2024-01-01", periods=1, freq="D")
+    s = pd.Series([1.0], index=idx)
+    freq, reason = inferred_regular_freq(s)
+    assert reason == "degenerate"
+    assert freq == pd.Timedelta(0)
+
+
+def test_compare_regular_freq_both_regular_same():
+    i1 = pd.date_range("2024-01-01", periods=5, freq="D")
+    i2 = pd.date_range("2024-02-01", periods=3, freq="D")
+    s1 = pd.Series(range(5), index=i1)
+    s2 = pd.Series(range(3), index=i2)
+
+    status, reason, sf, rf = compare_regular_freq(s1, s2)
+    assert status == "both_regular_same"
+    assert sf == i1.freq
+    assert rf == i2.freq
+
+
+def test_compare_regular_freq_both_regular_different():
+    i1 = pd.date_range("2024-01-01", periods=5, freq="D")
+    i2 = pd.date_range("2024-02-01", periods=3, freq="2D")
+    s1 = pd.Series(range(5), index=i1)
+    s2 = pd.Series(range(3), index=i2)
+
+    status, _, sf, rf = compare_regular_freq(s1, s2)
+    assert status == "both_regular_different"
+    assert sf == i1.freq
+    assert rf == i2.freq
+
+
+def test_compare_regular_freq_src_irregular():
+    s1 = pd.Series([1, 2, 3], index=pd.to_datetime(["2024-01-01", "2024-01-02", "2024-01-04"]))
+    s2 = pd.Series([1, 2, 3], index=pd.date_range("2024-01-01", periods=3, freq="D"))
+
+    status, reason, sf, rf = compare_regular_freq(s1, s2)
+    assert status == "src_irregular"
+    assert sf is None
+    assert rf == s2.index.freq
+    assert "staged not regular" in reason
+
+
+def test_compare_regular_freq_dst_irregular():
+    s1 = pd.Series([1, 2, 3], index=pd.date_range("2024-01-01", periods=3, freq="D"))
+    s2 = pd.Series([1, 2, 3], index=pd.to_datetime(["2024-01-01", "2024-01-02", "2024-01-04"]))
+
+    status, reason, sf, rf = compare_regular_freq(s1, s2)
+    assert status == "dst_irregular"
+    assert sf == s1.index.freq
+    assert rf is None
+    assert "repo not regular" in reason
+
+
+def test_compare_regular_freq_both_irregular():
+    s1 = pd.Series([1, 2, 3], index=pd.to_datetime(["2024-01-01", "2024-01-02", "2024-01-04"]))
+    s2 = pd.Series([1, 2, 3], index=pd.to_datetime(["2024-02-01", "2024-02-03", "2024-02-04"]))
+
+    status, reason, sf, rf = compare_regular_freq(s1, s2)
+    assert status == "both_irregular"
+    assert sf is None
+    assert rf is None
+    assert "both irregular" in reason
+
+
+def test_compare_regular_freq_single_point_compatible():
+    idx1 = pd.date_range("2024-01-01", periods=1, freq="D")
+    idx2 = pd.date_range("2024-02-01", periods=1, freq="D")
+    s1 = pd.Series([1.0], index=idx1)
+    s2 = pd.Series([2.0], index=idx2)
+
+    status, reason, sf, rf = compare_regular_freq(s1, s2)
+    assert status == "both_regular_same"
+    assert reason == "degenerate_single_point"
+    assert sf is None
+    assert rf is None