test(source/cloud-storage): log teardown iterator errors and cover pageSize bounds

Cleanup loop in the integration test was treating any iterator error as
iterator.Done; now distinguishes the two and logs non-Done errors so
flaky teardowns are debuggable. Also adds an internal unit test for
pageSize covering 0, negative, in-range, and over-cap inputs.

Author: huangjiahua

internal/sources/cloudstorage/pagesize_internal_test.go

@@ -0,0 +1,37 @@
+// Copyright 2026 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package cloudstorage
+
+import "testing"
+
+func TestPageSize(t *testing.T) {
+	tcs := []struct {
+		in   int
+		want int
+	}{
+		{in: 0, want: 1000},
+		{in: -1, want: 1000},
+		{in: 1, want: 1},
+		{in: 500, want: 500},
+		{in: 1000, want: 1000},
+		{in: 1001, want: 1000},
+		{in: 1_000_000, want: 1000},
+	}
+	for _, tc := range tcs {
+		if got := pageSize(tc.in); got != tc.want {
+			t.Errorf("pageSize(%d) = %d, want %d", tc.in, got, tc.want)
+		}
+	}
+}

tests/cloudstorage/cloud_storage_integration_test.go

@@ -32,6 +32,7 @@ import (
 	"github.com/google/uuid"
 	"github.com/googleapis/mcp-toolbox/internal/testutils"
 	"github.com/googleapis/mcp-toolbox/tests"
+	"google.golang.org/api/iterator"
 	"google.golang.org/api/option"
 )
 
@@ -164,8 +165,11 @@ func setupCloudStorageTestData(t *testing.T, ctx context.Context, client *storag
 		it := bkt.Objects(cleanupCtx, nil)
 		for {
 			attrs, err := it.Next()
+			if err == iterator.Done {
+				break
+			}
 			if err != nil {
-				// iterator.Done or another error: stop iterating and attempt bucket delete.
+				t.Logf("cleanup: iterator error, aborting object delete loop: %v", err)
 				break
 			}
 			if delErr := bkt.Object(attrs.Name).Delete(cleanupCtx); delErr != nil {