Add unit tests

dask_sql/physical/rex/core/call.py

@@ -542,12 +542,10 @@ def __init__(self):
         super().__init__(self.replace)
 
     def replace(self, s, pat, repl):
-        if isinstance(s, str):
-            return s.replace(pat, repl)
-        elif isinstance(s, dd.Series):
-            return s.str.replace(pat, repl)
-        else:
-            raise TypeError("The string expression must be a string or a column name")
+        if is_frame(s):
+            s = s.str
+
+        return s.replace(pat, repl)
 
 
 class OverlayOperation(Operation):

tests/unit/test_call.py

@@ -182,6 +182,9 @@ def test_string_operations():
     assert ops_mapping["substring"](a, 2) == " normal string"
     assert ops_mapping["substring"](a, 2, 2) == " n"
     assert ops_mapping["initcap"](a) == "A Normal String"
+    assert ops_mapping["replace"](a, "nor", "") == "a mal string"
+    assert ops_mapping["replace"](a, "normal", "new") == "a new string"
+    assert ops_mapping["replace"]("hello", "", "w") == "whwewlwlwow"
 
 
 def test_dates():