chore: add a test for HeapSize() function (#3349)

Author: romange

src/facade/redis_parser_test.cc

@@ -10,6 +10,7 @@
 #include "absl/strings/str_cat.h"
 #include "base/gtest.h"
 #include "base/logging.h"
+#include "core/heap_size.h"
 #include "facade/facade_test.h"
 
 using namespace testing;
@@ -209,4 +210,24 @@ TEST_F(RedisParserTest, NestedArray) {
   ASSERT_THAT(args_[1].GetVec(), ElementsAre("car"));
 }
 
+TEST_F(RedisParserTest, UsedMemory) {
+  vector<vector<uint8_t>> blobs;
+  for (size_t i = 0; i < 100; ++i) {
+    blobs.emplace_back(vector<uint8_t>(200));
+  }
+  EXPECT_GT(dfly::HeapSize(blobs), 20000);
+
+  std::vector<std::unique_ptr<RespVec>> stash;
+  RespVec vec;
+  for (unsigned i = 0; i < 10; ++i) {
+    vec.emplace_back(RespExpr::STRING);
+    vec.back().u = RespExpr::Buffer(nullptr, 0);
+  }
+
+  for (unsigned i = 0; i < 100; i++) {
+    stash.emplace_back(new RespExpr::Vec(vec));
+  }
+  EXPECT_GT(dfly::HeapSize(stash), 30000);
+}
+
 }  // namespace facade