From 28811effddd992dc87bd277d4e9df3c20898bd41 Mon Sep 17 00:00:00 2001
From: Bert Blommers <info@bertblommers.nl>
Date: Tue, 30 Jan 2024 20:51:36 +0000
Subject: [PATCH] S3: list_objects_v2() should return more than 1000 files
 (#7283)

---
 moto/s3/models.py        | 14 +++++++++-----
 tests/test_s3/test_s3.py | 28 ++++++++++++++++++++++++++++
 2 files changed, 37 insertions(+), 5 deletions(-)

diff --git a/moto/s3/models.py b/moto/s3/models.py
index 36843aeb0..291459bcd 100644
--- a/moto/s3/models.py
+++ b/moto/s3/models.py
@@ -2451,7 +2451,7 @@ class S3Backend(BaseBackend, CloudWatchMetricProvider):
         prefix: Optional[str],
         delimiter: Optional[str],
         marker: Optional[str],
-        max_keys: int,
+        max_keys: Optional[int],
     ) -> Tuple[Set[FakeKey], Set[str], bool, Optional[str]]:
         key_results = set()
         folder_results = set()
@@ -2487,9 +2487,13 @@ class S3Backend(BaseBackend, CloudWatchMetricProvider):
             limit = self._pagination_tokens.get(marker)
             key_results = self._get_results_from_token(key_results, limit)
 
-        key_results, is_truncated, next_marker = self._truncate_result(
-            key_results, max_keys
-        )
+        if max_keys is not None:
+            key_results, is_truncated, next_marker = self._truncate_result(
+                key_results, max_keys
+            )
+        else:
+            is_truncated = False
+            next_marker = None
 
         return key_results, folder_results, is_truncated, next_marker
 
@@ -2503,7 +2507,7 @@ class S3Backend(BaseBackend, CloudWatchMetricProvider):
         max_keys: int,
     ) -> Tuple[Set[Union[FakeKey, str]], bool, Optional[str]]:
         result_keys, result_folders, _, _ = self.list_objects(
-            bucket, prefix, delimiter, marker=None, max_keys=1000
+            bucket, prefix, delimiter, marker=None, max_keys=None
         )
         # sort the combination of folders and keys into lexicographical order
         all_keys = result_keys + result_folders  # type: ignore
diff --git a/tests/test_s3/test_s3.py b/tests/test_s3/test_s3.py
index 86dca6ffc..acee87f5c 100644
--- a/tests/test_s3/test_s3.py
+++ b/tests/test_s3/test_s3.py
@@ -21,6 +21,7 @@ import moto.s3.models as s3model
 from moto import mock_aws, moto_proxy, settings
 from moto.core.utils import utcnow
 from moto.moto_api import state_manager
+from moto.s3.models import s3_backends
 from moto.s3.responses import DEFAULT_REGION_NAME
 from tests import DEFAULT_ACCOUNT_ID
 
@@ -1453,6 +1454,33 @@ def test_list_objects_v2_truncate_combined_keys_and_folders():
     assert resp["CommonPrefixes"][0]["Prefix"] == "3/"
 
 
+@mock_aws
+def test_list_objects_v2__more_than_1000():
+    # Verify that the default pagination size (1000) works
+    if not settings.TEST_DECORATOR_MODE:
+        raise SkipTest("Accessing backends directly")
+    s3_client = boto3.client("s3", region_name=DEFAULT_REGION_NAME)
+    s3_client.create_bucket(Bucket="mybucket")
+
+    # Uploading >1000 files using boto3 takes ages, so let's just use the backend directly
+    backend = s3_backends[DEFAULT_ACCOUNT_ID]["global"]
+    for i in range(1100):
+        backend.put_object(bucket_name="mybucket", key_name=f"{i}", value=b"")
+
+    # Page 1
+    resp = s3_client.list_objects_v2(Bucket="mybucket", Delimiter="/")
+    assert resp["KeyCount"] == 1000
+    assert len(resp["Contents"]) == 1000
+    assert resp["IsTruncated"] is True
+
+    # Page2
+    tail = resp["Contents"][-1]["Key"]
+    resp = s3_client.list_objects_v2(Bucket="mybucket", Delimiter="/", StartAfter=tail)
+    assert resp["KeyCount"] == 100
+    assert len(resp["Contents"]) == 100
+    assert resp["IsTruncated"] is False
+
+
 @mock_aws
 def test_list_objects_v2_checksum_algo():
     s3_client = boto3.client("s3", region_name=DEFAULT_REGION_NAME)