Add test for log

Author: judahrand

datafusion/tests/test_functions.py

@@ -133,6 +133,7 @@ def test_math_functions():
         f.factorial(literal(6)),
         f.isnan(col_nav),
         f.iszero(col_nav),
+        f.log(literal(3), col_v + literal(pa.scalar(1))),
     )
     batches = df.collect()
     assert len(batches) == 1
@@ -189,6 +190,9 @@ def test_math_functions():
     np.testing.assert_array_almost_equal(result.column(34), math.factorial(6))
     np.testing.assert_array_almost_equal(result.column(35), np.isnan(na_values))
     np.testing.assert_array_almost_equal(result.column(36), na_values == 0)
+    np.testing.assert_array_almost_equal(
+        result.column(37), np.emath.logn(3, values + 1.0)
+    )
 
 
 def test_string_functions(df):