add unittest, both positiv and negative 'rain.1h' column

tests/unit/test_rain.py

@@ -0,0 +1,37 @@
+import unittest
+import sys
+import os
+import pandas as pd
+import numpy as np
+
+# Add the src folder to the Python path
+sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), '../../src')))
+
+from my_package.util import ensure_rain_column
+from my_package.util import fill_rain_column
+
+
+class TestRain(unittest.TestCase):
+    def test_ensure_rain(self):
+        # Creates a df with the column 'something' and the value NaN
+        self.df = pd.DataFrame([[np.nan]], columns=['something'])
+
+        # Runs the function that should create a column 'rain.1h' if its not already existing
+        self.df = ensure_rain_column(self.df)
+
+        # Checks if the column 'rain.1h' is in the columns of the dataframe
+        self.assertIn('rain.1h', self.df.columns)
+
+    def test_fill_rain(self):
+        # Creates a dataframe with the column 'rain.1h' and value NaN
+        self.df = pd.DataFrame([[np.nan]], columns=['rain.1h'])
+
+        # Runs the function, that should replace NaN with 0
+        self.df = fill_rain_column(self.df)
+
+        # Checks if the first index in the 'rain.1h' column is not equal to NaN, aka the value has changed
+        self.assertNotEqual(self.df['rain.1h'][0], np.nan)
+
+if __name__ == "__main__":
+    unittest.main()
+