feat: add batch_items utility for chunking lists

Author: vertti

src/lazy_ecs/core/utils.py

@@ -8,7 +8,7 @@
 import threading
 from collections.abc import Iterator
 from contextlib import contextmanager, suppress
-from typing import TYPE_CHECKING, Literal
+from typing import TYPE_CHECKING, Any, Literal
 
 from rich.console import Console
 from rich.spinner import Spinner
@@ -80,6 +80,12 @@ def show_spinner() -> Iterator[None]:
         yield
 
 
+def batch_items(items: list[Any], batch_size: int) -> Iterator[list[Any]]:
+    """Split a list into batches of specified size."""
+    for i in range(0, len(items), batch_size):
+        yield items[i : i + batch_size]
+
+
 def paginate_aws_list(
     client: ECSClient,
     operation_name: Literal[

tests/test_utils.py

@@ -0,0 +1,60 @@
+"""Tests for utility functions."""
+
+from lazy_ecs.core.utils import batch_items
+
+
+def test_batch_items_basic():
+    items = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
+    batches = list(batch_items(items, 3))
+
+    assert len(batches) == 4
+    assert batches[0] == [1, 2, 3]
+    assert batches[1] == [4, 5, 6]
+    assert batches[2] == [7, 8, 9]
+    assert batches[3] == [10]
+
+
+def test_batch_items_exact_fit():
+    items = [1, 2, 3, 4, 5, 6]
+    batches = list(batch_items(items, 3))
+
+    assert len(batches) == 2
+    assert batches[0] == [1, 2, 3]
+    assert batches[1] == [4, 5, 6]
+
+
+def test_batch_items_single_batch():
+    items = [1, 2, 3]
+    batches = list(batch_items(items, 10))
+
+    assert len(batches) == 1
+    assert batches[0] == [1, 2, 3]
+
+
+def test_batch_items_empty_list():
+    items = []
+    batches = list(batch_items(items, 5))
+
+    assert len(batches) == 0
+
+
+def test_batch_items_size_one():
+    items = [1, 2, 3, 4, 5]
+    batches = list(batch_items(items, 1))
+
+    assert len(batches) == 5
+    assert batches[0] == [1]
+    assert batches[1] == [2]
+    assert batches[2] == [3]
+    assert batches[3] == [4]
+    assert batches[4] == [5]
+
+
+def test_batch_items_strings():
+    items = ["a", "b", "c", "d", "e", "f", "g"]
+    batches = list(batch_items(items, 3))
+
+    assert len(batches) == 3
+    assert batches[0] == ["a", "b", "c"]
+    assert batches[1] == ["d", "e", "f"]
+    assert batches[2] == ["g"]