AI spam

.gitignore

@@ -6,3 +6,4 @@ dist/
 htmlcov/
 .tox/
 docs/_build/
+.venv/

src/jinja2/filters.py

@@ -1089,7 +1089,11 @@ def sync_do_slice(
         end = offset + (slice_number + 1) * items_per_slice
         tmp = seq[start:end]
 
-        if fill_with is not None and slice_number >= slices_with_extra:
+        if (
+            fill_with is not None
+            and slices_with_extra > 0
+            and slice_number >= slices_with_extra
+        ):
             tmp.append(fill_with)
 
         yield tmp

tests/test_slice_fill_fix.py

@@ -0,0 +1,84 @@
+"""Tests for slice filter fix: fill_with should not be applied when
+iterable length is evenly divisible by slice count.
+
+Regression test for https://github.com/pallets/jinja/issues/2118
+"""
+
+import pytest
+
+from jinja2 import Environment
+
+
+@pytest.fixture
+def env():
+    return Environment()
+
+
+class TestSliceFillWithEvenDivision:
+    """slice(x, fill) when len % slices == 0 should not add fill values."""
+
+    def test_slice_4_items_4_slices_with_fill(self, env):
+        """4 items into 4 slices: each gets exactly 1 item, no fill."""
+        tmpl = env.from_string("{{ [1, 2, 3, 4]|slice(4, 'foo')|list }}")
+        result = tmpl.render()
+        assert result == "[[1], [2], [3], [4]]"
+
+    def test_slice_6_items_3_slices_with_fill(self, env):
+        """6 items into 3 slices: each gets exactly 2 items, no fill."""
+        tmpl = env.from_string("{{ [1, 2, 3, 4, 5, 6]|slice(3, 'x')|list }}")
+        result = tmpl.render()
+        assert result == "[[1, 2], [3, 4], [5, 6]]"
+
+    def test_slice_8_items_4_slices_with_fill(self, env):
+        """8 items into 4 slices: each gets exactly 2 items, no fill."""
+        tmpl = env.from_string("{{ [1,2,3,4,5,6,7,8]|slice(4, 'z')|list }}")
+        result = tmpl.render()
+        assert result == "[[1, 2], [3, 4], [5, 6], [7, 8]]"
+
+    def test_slice_1_item_1_slice_with_fill(self, env):
+        """1 item into 1 slice: no fill needed."""
+        tmpl = env.from_string("{{ [42]|slice(1, 'fill')|list }}")
+        result = tmpl.render()
+        assert result == "[[42]]"
+
+    def test_slice_10_items_5_slices_with_fill(self, env):
+        """10 items into 5 slices: each gets exactly 2 items, no fill."""
+        tmpl = env.from_string("{{ [1,2,3,4,5,6,7,8,9,10]|slice(5, 'fill')|list }}")
+        result = tmpl.render()
+        assert result == "[[1, 2], [3, 4], [5, 6], [7, 8], [9, 10]]"
+
+
+class TestSliceFillWithRemainder:
+    """slice(x, fill) when len % slices != 0 should still fill correctly."""
+
+    def test_slice_5_items_3_slices_with_fill(self, env):
+        """5 items into 3 slices: first 2 slices get 2 items, last gets 1 + fill."""
+        tmpl = env.from_string("{{ [1,2,3,4,5]|slice(3, 'x')|list }}")
+        result = tmpl.render()
+        assert result == "[[1, 2], [3, 4], [5, 'x']]"
+
+    def test_slice_7_items_3_slices_with_fill(self, env):
+        """7 items into 3 slices: first slice gets 3, rest get 2+fill."""
+        tmpl = env.from_string("{{ [1,2,3,4,5,6,7]|slice(3, 'f')|list }}")
+        result = tmpl.render()
+        assert result == "[[1, 2, 3], [4, 5, 'f'], [6, 7, 'f']]"
+
+    def test_slice_3_items_4_slices_with_fill(self, env):
+        """3 items into 4 slices: first 3 get 1 item each, last gets fill."""
+        tmpl = env.from_string("{{ [1,2,3]|slice(4, 'x')|list }}")
+        result = tmpl.render()
+        assert result == "[[1], [2], [3], ['x']]"
+
+
+class TestSliceNoFill:
+    """slice(x) without fill_with should work the same regardless."""
+
+    def test_slice_4_items_4_slices_no_fill(self, env):
+        tmpl = env.from_string("{{ [1, 2, 3, 4]|slice(4)|list }}")
+        result = tmpl.render()
+        assert result == "[[1], [2], [3], [4]]"
+
+    def test_slice_7_items_3_slices_no_fill(self, env):
+        tmpl = env.from_string("{{ [1,2,3,4,5,6,7]|slice(3)|list }}")
+        result = tmpl.render()
+        assert result == "[[1, 2, 3], [4, 5], [6, 7]]"