Test Series.

tests/pricehist/test_series.py

@@ -0,0 +1,95 @@
+from dataclasses import replace
+from decimal import Decimal
+
+import pytest
+
+from pricehist.price import Price
+from pricehist.series import Series
+
+
+@pytest.fixture
+def series():
+    return Series(
+        "BASE",
+        "QUOTE",
+        "type",
+        "2021-01-01",
+        "2021-06-30",
+        [
+            Price("2021-01-01", Decimal("1.0123456789")),
+            Price("2021-01-02", Decimal("2.01234567890123456789")),
+            Price("2021-01-03", Decimal("3.012345678901234567890123456789")),
+        ],
+    )
+
+
+def test_invert(series):
+    result = series.invert()
+    assert (series.base, series.quote) == ("BASE", "QUOTE")
+    assert (result.base, result.quote) == ("QUOTE", "BASE")
+
+
+def test_rename_base(series):
+    result = series.rename_base("NEWBASE")
+    assert series.base == "BASE"
+    assert result.base == "NEWBASE"
+
+
+def test_rename_quote(series):
+    result = series.rename_quote("NEWQUOTE")
+    assert series.quote == "QUOTE"
+    assert result.quote == "NEWQUOTE"
+
+
+def test_quantize_rounds_half_even(series):
+    subject = replace(
+        series,
+        prices=[
+            Price("2021-01-01", Decimal("1.14")),
+            Price("2021-01-02", Decimal("2.25")),
+            Price("2021-01-03", Decimal("3.35")),
+            Price("2021-01-04", Decimal("4.46")),
+        ],
+    )
+    amounts = [p.amount for p in subject.quantize(1).prices]
+    assert amounts == [
+        Decimal("1.1"),
+        Decimal("2.2"),
+        Decimal("3.4"),
+        Decimal("4.5"),
+    ]
+
+
+def test_quantize_does_not_extend(series):
+    subject = replace(
+        series,
+        prices=[
+            Price("2021-01-01", Decimal("1.14")),
+            Price("2021-01-02", Decimal("2.25")),
+            Price("2021-01-03", Decimal("3.35")),
+            Price("2021-01-04", Decimal("4.46")),
+        ],
+    )
+    amounts = [p.amount for p in subject.quantize(3).prices]
+    assert amounts == [
+        Decimal("1.14"),
+        Decimal("2.25"),
+        Decimal("3.35"),
+        Decimal("4.46"),
+    ]
+
+
+def test_quantize_does_not_go_beyond_context_max_prec(series):
+    subject = replace(
+        series,
+        prices=[
+            Price("2021-01-01", Decimal("1.012345678901234567890123456789")),
+        ],
+    )
+    assert subject.prices[0].amount == Decimal("1.012345678901234567890123456789")
+    result0 = subject.quantize(26)
+    result1 = subject.quantize(27)
+    result2 = subject.quantize(35)
+    assert result0.prices[0].amount == Decimal("1.01234567890123456789012346")
+    assert result1.prices[0].amount == Decimal("1.012345678901234567890123457")
+    assert result2.prices[0].amount == Decimal("1.012345678901234567890123457")