add more tests

tests/test_dac_totals.py

@@ -0,0 +1,146 @@
+import pandas as pd
+
+from pydeflate import oecd_dac_deflate
+
+data = {
+    "year": [2020, 2021, 2022, 2023],
+    "indicator": ["total_oda_official_definition"] * 4,
+    "donor_code": [12] * 4,
+    "currency": ["USD"] * 4,
+    "prices": ["current"] * 4,
+    "value": [18568.19, 15712.01, 15761.81, 19110.59],
+    "expected_value": [16312, 12885, 13717, 15374],
+}
+
+df = pd.DataFrame(data)
+
+data_usd = {
+    "year": [2020, 2021, 2022, 2023],
+    "indicator": ["total_oda_official_definition"] * 4,
+    "donor_code": [302] * 4,
+    "currency": ["USD"] * 4,
+    "prices": ["current"] * 4,
+    "value": [35576.31, 47804.8, 60522.41, 66040.03],
+    "expected_value": [41326, 53097, 62800, 66040],
+}
+
+
+df_usd = pd.DataFrame(data_usd)
+
+data_eur = {
+    "year": [2020, 2021, 2022, 2023],
+    "indicator": ["total_oda_official_definition"] * 4,
+    "donor_code": [742] * 4,
+    "currency": ["EUR"] * 4,
+    "prices": ["current"] * 4,
+    "value": [1974, 2429, 2672, 2986],
+    "expected_value": [1995, 2403, 2619, 2896],
+}
+df_eur = pd.DataFrame(data_eur)
+
+
+data_can = {
+    "year": [2020, 2021, 2022, 2023],
+    "indicator": ["total_oda_official_definition"] * 4,
+    "donor_code": [5] * 4,
+    "currency": ["CAD"] * 4,
+    "prices": ["current"] * 4,
+    "value": [38503, 41707, 46393, 49495],
+    "expected_value": [31404, 34049, 38957, 36682],
+}
+df_can = pd.DataFrame(data_can)
+
+
+data_lcu = {
+    "year": [2020, 2021, 2022, 2023],
+    "indicator": ["total_oda_official_definition"] * 4,
+    "donor_code": [4] * 4,
+    "currency": ["EUR"] * 4,
+    "prices": ["current"] * 4,
+    "value": [12394, 13112, 15228, 14266],
+    "expected_value": [13625, 14210, 16031, 14266],
+}
+df_lcu = pd.DataFrame(data_lcu)
+
+
+def run_constant_test(
+    data,
+    source_currency,
+    target_currency,
+    tolerance=0.05,
+    base_year=2023,
+    id_column="donor_code",
+    target_value_column="value",
+):
+    """
+    Runs a test for deflation calculation with given parameters and tolerance.
+
+    Args:
+        data (pd.DataFrame): The input DataFrame containing the data to deflate.
+        source_currency (str): The source currency code.
+        target_currency (str): The target currency code.
+        tolerance (float, optional): The allowed tolerance for deviation. Defaults to 0.05.
+        base_year (int, optional): The base year for deflation. Defaults to 2023.
+        id_column (str, optional): Column name for IDs. Defaults to "donor_code".
+        target_value_column (str, optional): Column name for the target value. Defaults to "value".
+
+    Raises:
+        AssertionError: If any row exceeds the tolerance threshold.
+    """
+    # Perform the deflation calculation
+    test_df = oecd_dac_deflate(
+        data=data,
+        base_year=base_year,
+        source_currency=source_currency,
+        target_currency=target_currency,
+        id_column=id_column,
+        use_source_codes=True,
+        target_value_column=target_value_column,
+    )
+
+    # Calculate the percentage deviation
+    deviations = abs(
+        (test_df[target_value_column] - test_df["expected_value"])
+        / test_df["expected_value"]
+    )
+
+    # Filter out rows where value is NaN and deviations exceed tolerance
+    mask = test_df[target_value_column].notna() & (deviations >= tolerance)
+    failing_rows = test_df[mask]
+
+    # Assert that no rows exceed the tolerance
+    assert failing_rows.empty, (
+        f"Deviation exceeded {tolerance*100:.2f}% in the following "
+        f"donors:\n{failing_rows[id_column].unique()}"
+    )
+
+
+# Define test cases with parameters
+def test_to_constant():
+    run_constant_test(
+        data=df, source_currency="USA", target_currency="GBP", tolerance=0.01
+    )
+
+
+def test_to_constant_usd():
+    run_constant_test(
+        data=df_usd, source_currency="USA", target_currency="USA", tolerance=0.01
+    )
+
+
+def test_to_constant_eur():
+    run_constant_test(
+        data=df_eur, source_currency="EUR", target_currency="EUR", tolerance=0.05
+    )
+
+
+def test_to_constant_can():
+    run_constant_test(
+        data=df_can, source_currency="CAN", target_currency="USA", tolerance=0.05
+    )
+
+
+def test_to_constant_lcu():
+    run_constant_test(
+        data=df_lcu, source_currency="EUR", target_currency="LCU", tolerance=0.05
+    )