codegen unit tests

Author: Casper-Guo

src/latexify/codegen/function_codegen_test.py

@@ -228,6 +228,15 @@ def test_visit_call_sum_prod(src_suffix: str, dest_suffix: str) -> None:
             "math.prod(i for i in range(n-1))",
             r"\prod_{i = {0}}^{{n - {2}}} \mathopen{}\left({i}\mathclose{}\right)",
         ),
+        # reduce stop parameter
+        (
+            "sum(i for i in range(n+1))",
+            r"\sum_{i = {0}}^{{n}} \mathopen{}\left({i}\mathclose{}\right)",
+        ),
+        (
+            "math.prod(i for i in range(n-1))",
+            r"\prod_{i = {0}}^{{n - {2}}} \mathopen{}\left({i}\mathclose{}\right)",
+        ),
     ],
 )
 def test_visit_call_sum_prod_multiple_comprehension(code: str, latex: str) -> None: