Fix: ListObjectsV2 behaving differently than AWS API (#3545)

* fix : localstack issue https://github.com/issues?q=is%3Aopen+is%3Aissue+label%3A%22good+first+issue%22+language%3Ago

* add assertion for error message as well

moto/s3/exceptions.py

@@ -424,3 +424,15 @@ class InvalidRange(S3ClientError):
             actual_size=actual_size,
             **kwargs
         )
+
+
+class InvalidContinuationToken(S3ClientError):
+    code = 400
+
+    def __init__(self, *args, **kwargs):
+        super(InvalidContinuationToken, self).__init__(
+            "InvalidArgument",
+            "The continuation token provided is incorrect",
+            *args,
+            **kwargs
+        )

moto/s3/responses.py

@@ -25,6 +25,7 @@ from moto.s3bucket_path.utils import (
 from .exceptions import (
     BucketAlreadyExists,
     DuplicateTagKeys,
+    InvalidContinuationToken,
     S3ClientError,
     MissingBucket,
     MissingKey,
@@ -529,6 +530,10 @@ class ResponseObject(_TemplateEnvironmentMixin, ActionAuthenticatorMixin):
         template = self.response_template(S3_BUCKET_GET_RESPONSE_V2)
         bucket = self.backend.get_bucket(bucket_name)
 
+        continuation_token = querystring.get("continuation-token", [None])[0]
+        if continuation_token is not None and continuation_token == "":
+            raise InvalidContinuationToken()
+
         prefix = querystring.get("prefix", [None])[0]
         if prefix and isinstance(prefix, six.binary_type):
             prefix = prefix.decode("utf-8")
@@ -539,7 +544,6 @@ class ResponseObject(_TemplateEnvironmentMixin, ActionAuthenticatorMixin):
 
         fetch_owner = querystring.get("fetch-owner", [False])[0]
         max_keys = int(querystring.get("max-keys", [1000])[0])
-        continuation_token = querystring.get("continuation-token", [None])[0]
         start_after = querystring.get("start-after", [None])[0]
 
         # sort the combination of folders and keys into lexicographical order

tests/test_s3/test_s3.py

@@ -1809,6 +1809,32 @@ def test_boto3_list_objects_v2_common_prefix_pagination():
     assert prefixes == [k[: k.rindex("/") + 1] for k in keys]
 
 
+@mock_s3
+def test_boto3_list_objects_v2_common_invalid_continuation_token():
+    s3 = boto3.client("s3", region_name=DEFAULT_REGION_NAME)
+    s3.create_bucket(Bucket="mybucket")
+
+    max_keys = 1
+    keys = ["test/{i}/{i}".format(i=i) for i in range(3)]
+    for key in keys:
+        s3.put_object(Bucket="mybucket", Key=key, Body=b"v")
+
+    args = {
+        "Bucket": "mybucket",
+        "Delimiter": "/",
+        "Prefix": "test/",
+        "MaxKeys": max_keys,
+        "ContinuationToken": "",
+    }
+
+    with pytest.raises(botocore.exceptions.ClientError) as exc:
+        s3.list_objects_v2(**args)
+    exc.value.response["Error"]["Code"].should.equal("InvalidArgument")
+    exc.value.response["Error"]["Message"].should.equal(
+        "The continuation token provided is incorrect"
+    )
+
+
 @mock_s3
 def test_boto3_list_objects_v2_truncated_response():
     s3 = boto3.client("s3", region_name=DEFAULT_REGION_NAME)