From 7ee361f7ad3806258e3c9a7ea2fc8dce5fdb54bc Mon Sep 17 00:00:00 2001
From: Julian Becker <becker.julian@gmail.com>
Date: Sat, 15 Sep 2018 11:54:17 +0200
Subject: [PATCH] BSON: support objects with int32 members

---
 .../nlohmann/detail/input/binary_reader.hpp   | 10 ++++++++
 .../nlohmann/detail/output/binary_writer.hpp  | 14 +++++++++++
 single_include/nlohmann/json.hpp              | 24 +++++++++++++++++++
 test/src/unit-bson.cpp                        | 24 +++++++++++++++++++
 4 files changed, 72 insertions(+)

diff --git a/include/nlohmann/detail/input/binary_reader.hpp b/include/nlohmann/detail/input/binary_reader.hpp
index 3fd6cc20..f11e164e 100644
--- a/include/nlohmann/detail/input/binary_reader.hpp
+++ b/include/nlohmann/detail/input/binary_reader.hpp
@@ -203,6 +203,16 @@ class binary_reader
                     sax->boolean(static_cast<bool>(get()));
                 }
                 break;
+                case 0x10: // int32
+                {
+                    string_t key;
+                    get_bson_cstr(key);
+                    sax->key(key);
+                    std::int32_t value;
+                    get_number_little_endian(value);
+                    sax->number_integer(static_cast<std::int32_t>(value));
+                }
+                break;
                 case 0x0A: // null
                 {
                     string_t key;
diff --git a/include/nlohmann/detail/output/binary_writer.hpp b/include/nlohmann/detail/output/binary_writer.hpp
index 966d8c22..ed59b7c2 100644
--- a/include/nlohmann/detail/output/binary_writer.hpp
+++ b/include/nlohmann/detail/output/binary_writer.hpp
@@ -721,6 +721,18 @@ class binary_writer
         return /*id*/ 1ul + name.size() + 1ul;
     }
 
+    std::size_t write_bson_integer(const typename BasicJsonType::string_t& name, const BasicJsonType& j)
+    {
+        oa->write_character(static_cast<CharType>(0x10)); // int32
+        oa->write_characters(
+            reinterpret_cast<const CharType*>(name.c_str()),
+            name.size() + 1u);
+
+        write_number_little_endian(static_cast<std::int32_t>(j.m_value.number_integer));
+
+        return /*id*/ 1ul + name.size() + 1ul + sizeof(std::int32_t);
+    }
+
     std::size_t write_bson_object_entry(const typename BasicJsonType::string_t& name, const BasicJsonType& j)
     {
         switch (j.type())
@@ -732,6 +744,8 @@ class binary_writer
                 return write_bson_boolean(name, j);
             case value_t::number_float:
                 return write_bson_double(name, j);
+            case value_t::number_integer:
+                return write_bson_integer(name, j);
             case value_t::string:
                 return write_bson_string(name, j);
             case value_t::null:
diff --git a/single_include/nlohmann/json.hpp b/single_include/nlohmann/json.hpp
index faeaf214..d0cce8a1 100644
--- a/single_include/nlohmann/json.hpp
+++ b/single_include/nlohmann/json.hpp
@@ -6187,6 +6187,16 @@ class binary_reader
                     sax->boolean(static_cast<bool>(get()));
                 }
                 break;
+                case 0x10: // int32
+                {
+                    string_t key;
+                    get_bson_cstr(key);
+                    sax->key(key);
+                    std::int32_t value;
+                    get_number_little_endian(value);
+                    sax->number_integer(static_cast<std::int32_t>(value));
+                }
+                break;
                 case 0x0A: // null
                 {
                     string_t key;
@@ -8535,6 +8545,18 @@ class binary_writer
         return /*id*/ 1ul + name.size() + 1ul;
     }
 
+    std::size_t write_bson_integer(const typename BasicJsonType::string_t& name, const BasicJsonType& j)
+    {
+        oa->write_character(static_cast<CharType>(0x10)); // int32
+        oa->write_characters(
+            reinterpret_cast<const CharType*>(name.c_str()),
+            name.size() + 1u);
+
+        write_number_little_endian(static_cast<std::int32_t>(j.m_value.number_integer));
+
+        return /*id*/ 1ul + name.size() + 1ul + sizeof(std::int32_t);
+    }
+
     std::size_t write_bson_object_entry(const typename BasicJsonType::string_t& name, const BasicJsonType& j)
     {
         switch (j.type())
@@ -8546,6 +8568,8 @@ class binary_writer
                 return write_bson_boolean(name, j);
             case value_t::number_float:
                 return write_bson_double(name, j);
+            case value_t::number_integer:
+                return write_bson_integer(name, j);
             case value_t::string:
                 return write_bson_string(name, j);
             case value_t::null:
diff --git a/test/src/unit-bson.cpp b/test/src/unit-bson.cpp
index e83e112a..266dd12a 100644
--- a/test/src/unit-bson.cpp
+++ b/test/src/unit-bson.cpp
@@ -231,6 +231,30 @@ TEST_CASE("BSON")
             CHECK(json::from_bson(result, true, false) == j);
         }
 
+        SECTION("non-empty object with integer (32-bit) member")
+        {
+            json j =
+            {
+                { "entry", std::int32_t{0x12345678} }
+            };
+
+            std::vector<uint8_t> expected =
+            {
+                0x10, 0x00, 0x00, 0x00, // size (little endian)
+                0x10, /// entry: int32
+                'e', 'n', 't', 'r', 'y', '\x00',
+                0x78, 0x56, 0x34, 0x12,
+                0x00 // end marker
+            };
+
+            const auto result = json::to_bson(j);
+            CHECK(result == expected);
+
+            // roundtrip
+            CHECK(json::from_bson(result) == j);
+            CHECK(json::from_bson(result, true, false) == j);
+        }
+
 
     }
 }