fix(storage): json["projectTeam"] might be present but null (#8446)

Co-authored-by: Carlos O'Ryan <[email protected]>

Author: martinzink

google/cloud/storage/internal/access_control_common_parser.cc

@@ -36,6 +36,7 @@ Status AccessControlCommonParser::FromJson(AccessControlCommon& result,
   result.self_link_ = json.value("selfLink", "");
   if (json.count("projectTeam") != 0) {
     auto tmp = json["projectTeam"];
+    if (tmp.is_null()) return Status{};
     ProjectTeam p;
     p.project_number = tmp.value("projectNumber", "");
     p.team = tmp.value("team", "");

google/cloud/storage/internal/access_control_common_parser_test.cc

@@ -37,6 +37,16 @@ TEST(AccessControlCommonParserTest, FromJson) {
   EXPECT_THAT(result.bucket(), Eq(bucket));
   EXPECT_THAT(result.role(), Eq(role));
   EXPECT_THAT(result.email(), Eq(email));
+  EXPECT_FALSE(result.has_project_team());
+}
+
+TEST(AccessControlCommonParserTest, NullProjectTeamIsValid) {
+  nlohmann::json metadata{{"projectTeam", nullptr}};
+  internal::AccessControlCommon result{};
+  auto status = internal::AccessControlCommonParser::FromJson(result, metadata);
+  ASSERT_STATUS_OK(status);
+
+  EXPECT_FALSE(result.has_project_team());
 }
 
 }  // namespace