From 2877c343e8f2f50a0fe28b41ec3e740492c6c191 Mon Sep 17 00:00:00 2001
From: imilinovic <44698587+imilinovic@users.noreply.github.com>
Date: Tue, 1 Aug 2023 19:30:23 +0200
Subject: [PATCH] Add implementation of << operator for mgp::Value (#1127)

---
 include/mgp.hpp        | 50 ++++++++++++++++++++++++++++++++++++++++++
 tests/unit/cpp_api.cpp | 25 +++++++++++++++++++++
 2 files changed, 75 insertions(+)

diff --git a/include/mgp.hpp b/include/mgp.hpp
index e495c57eb..bd7c35983 100644
--- a/include/mgp.hpp
+++ b/include/mgp.hpp
@@ -1203,6 +1203,8 @@ class Value {
 
   bool operator<(const Value &other) const;
 
+  friend std::ostream &operator<<(std::ostream &os, const mgp::Value &value);
+
  private:
   mgp_value *ptr_;
 };
@@ -3491,6 +3493,54 @@ inline bool Value::operator<(const Value &other) const {
   }
 }
 
+inline std::ostream &operator<<(std::ostream &os, const mgp::Value &value) {
+  switch (value.Type()) {
+    case mgp::Type::Null:
+      return os << "null";
+    case mgp::Type::Any:
+      return os << "any";
+    case mgp::Type::Bool:
+      return os << (value.ValueBool() ? "true" : "false");
+    case mgp::Type::Int:
+      return os << std::to_string(value.ValueInt());
+    case mgp::Type::Double:
+      return os << std::to_string(value.ValueDouble());
+    case mgp::Type::String:
+      return os << std::string(value.ValueString());
+    case mgp::Type::List:
+      throw mgp::ValueException("Printing mgp::List type currently not supported.");
+    case mgp::Type::Map:
+      throw mgp::ValueException("Printing mgp::Map type currently not supported.");
+    case mgp::Type::Node:
+      return os << "Node[" + std::to_string(value.ValueNode().Id().AsInt()) + "]";
+    case mgp::Type::Relationship:
+      return os << "Relationship[" + std::to_string(value.ValueRelationship().Id().AsInt()) + "]";
+    case mgp::Type::Path:
+      throw mgp::ValueException("Printing mgp::Path type currently not supported.");
+    case mgp::Type::Date: {
+      const auto date{value.ValueDate()};
+      return os << std::to_string(date.Year()) + "-" + std::to_string(date.Month()) + "-" + std::to_string(date.Day());
+    }
+    case mgp::Type::LocalTime: {
+      const auto localTime{value.ValueLocalTime()};
+      return os << std::to_string(localTime.Hour()) + ":" + std::to_string(localTime.Minute()) + ":" +
+                       std::to_string(localTime.Second()) + "," + std::to_string(localTime.Millisecond()) +
+                       std::to_string(localTime.Microsecond());
+    }
+    case mgp::Type::LocalDateTime: {
+      const auto localDateTime = value.ValueLocalDateTime();
+      return os << std::to_string(localDateTime.Year()) + "-" + std::to_string(localDateTime.Month()) + "-" +
+                       std::to_string(localDateTime.Day()) + "T" + std::to_string(localDateTime.Hour()) + ":" +
+                       std::to_string(localDateTime.Minute()) + ":" + std::to_string(localDateTime.Second()) + "," +
+                       std::to_string(localDateTime.Millisecond()) + std::to_string(localDateTime.Microsecond());
+    }
+    case mgp::Type::Duration:
+      return os << std::to_string(value.ValueDuration().Microseconds()) + "ms";
+    default:
+      throw mgp::ValueException("Unknown value type");
+  }
+}
+
 inline std::ostream &operator<<(std::ostream &os, const mgp::Type &type) {
   switch (type) {
     case mgp::Type::Null:
diff --git a/tests/unit/cpp_api.cpp b/tests/unit/cpp_api.cpp
index 522e165cb..4c7ba2d25 100644
--- a/tests/unit/cpp_api.cpp
+++ b/tests/unit/cpp_api.cpp
@@ -560,3 +560,28 @@ TYPED_TEST(CppApiTestFixture, TestMapErase) {
   map.Erase("2");
   ASSERT_EQ(map.Size(), 0);
 }
+
+TYPED_TEST(CppApiTestFixture, TestValuePrint) {
+  std::string string_1{"abc"};
+  int64_t int_1{4};
+  mgp::Date date_1{"2020-12-12"};
+
+  mgp::Value string_value{string_1};
+  mgp::Value int_value{int_1};
+  mgp::Value date_value{date_1};
+
+  std::ostringstream oss_str;
+  oss_str << string_value;
+  std::string str_test = oss_str.str();
+  ASSERT_EQ(string_1, str_test);
+
+  std::ostringstream oss_int;
+  oss_int << int_value;
+  std::string int_test = oss_int.str();
+  ASSERT_EQ("4", int_test);
+
+  std::ostringstream oss_date;
+  oss_date << date_value;
+  std::string date_test = oss_date.str();
+  ASSERT_EQ("2020-12-12", date_test);
+}