💚 add test cases for hash

include/nlohmann/detail/hash.hpp

@@ -8,7 +8,7 @@ namespace nlohmann
 namespace detail
 {
 
-std::size_t combine(std::size_t seed, std::size_t h)
+std::size_t combine(std::size_t seed, std::size_t h) noexcept
 {
     seed ^= h + 0x9e3779b9 + (seed << 6U) + (seed >> 2U);
     return seed;
@@ -17,6 +17,11 @@ std::size_t combine(std::size_t seed, std::size_t h)
 template<typename BasicJsonType>
 std::size_t hash(const BasicJsonType& j)
 {
+    using string_t = typename BasicJsonType::string_t;
+    using number_integer_t = typename BasicJsonType::number_integer_t;
+    using number_unsigned_t = typename BasicJsonType::number_unsigned_t;
+    using number_float_t = typename BasicJsonType::number_float_t;
+
     switch (j.type())
     {
         case BasicJsonType::value_t::null:
@@ -28,7 +33,7 @@ std::size_t hash(const BasicJsonType& j)
             auto seed = combine(static_cast<std::size_t>(j.type()), j.size());
             for (const auto& element : j.items())
             {
-                const auto h = std::hash<typename BasicJsonType::string_t> {}(element.key());
+                const auto h = std::hash<string_t> {}(element.key());
                 seed = combine(seed, h);
                 seed = combine(seed, hash(element.value()));
             }
@@ -47,7 +52,7 @@ std::size_t hash(const BasicJsonType& j)
 
         case BasicJsonType::value_t::string:
         {
-            const auto h = std::hash<typename BasicJsonType::string_t> {}(j.template get_ref<const typename BasicJsonType::string_t&>());
+            const auto h = std::hash<string_t> {}(j.template get_ref<const string_t&>());
             return combine(static_cast<std::size_t>(j.type()), h);
         }
 
@@ -59,25 +64,27 @@ std::size_t hash(const BasicJsonType& j)
 
         case BasicJsonType::value_t::number_integer:
         {
-            const auto h = std::hash<typename BasicJsonType::number_integer_t> {}(j.template get<typename BasicJsonType::number_integer_t>());
+            const auto h = std::hash<number_integer_t> {}(j.template get<number_integer_t>());
             return combine(static_cast<std::size_t>(j.type()), h);
         }
 
         case nlohmann::detail::value_t::number_unsigned:
         {
-            const auto h = std::hash<typename BasicJsonType::number_unsigned_t> {}(j.template get<typename BasicJsonType::number_unsigned_t>());
+            const auto h = std::hash<number_unsigned_t> {}(j.template get<number_unsigned_t>());
             return combine(static_cast<std::size_t>(j.type()), h);
         }
 
         case nlohmann::detail::value_t::number_float:
         {
-            const auto h = std::hash<typename BasicJsonType::number_float_t> {}(j.template get<typename BasicJsonType::number_float_t>());
+            const auto h = std::hash<number_float_t> {}(j.template get<number_float_t>());
             return combine(static_cast<std::size_t>(j.type()), h);
         }
 
         case nlohmann::detail::value_t::binary:
         {
             auto seed = combine(static_cast<std::size_t>(j.type()), j.get_binary().size());
+            const auto h = std::hash<bool> {}(j.get_binary().has_subtype());
+            seed = combine(seed, h);
             seed = combine(seed, j.get_binary().subtype());
             for (const auto byte : j.get_binary())
             {
@@ -85,9 +92,10 @@ std::size_t hash(const BasicJsonType& j)
             }
             return seed;
         }
-    }
 
-    return 0;
+        default: // LCOV_EXCL_LINE
+            JSON_ASSERT(false); // LCOV_EXCL_LINE
+    }
 }
 
 }  // namespace detail

single_include/nlohmann/json.hpp

@@ -4453,7 +4453,7 @@ namespace nlohmann
 namespace detail
 {
 
-std::size_t combine(std::size_t seed, std::size_t h)
+std::size_t combine(std::size_t seed, std::size_t h) noexcept
 {
     seed ^= h + 0x9e3779b9 + (seed << 6U) + (seed >> 2U);
     return seed;
@@ -4462,6 +4462,11 @@ std::size_t combine(std::size_t seed, std::size_t h)
 template<typename BasicJsonType>
 std::size_t hash(const BasicJsonType& j)
 {
+    using string_t = typename BasicJsonType::string_t;
+    using number_integer_t = typename BasicJsonType::number_integer_t;
+    using number_unsigned_t = typename BasicJsonType::number_unsigned_t;
+    using number_float_t = typename BasicJsonType::number_float_t;
+
     switch (j.type())
     {
         case BasicJsonType::value_t::null:
@@ -4473,7 +4478,7 @@ std::size_t hash(const BasicJsonType& j)
             auto seed = combine(static_cast<std::size_t>(j.type()), j.size());
             for (const auto& element : j.items())
             {
-                const auto h = std::hash<typename BasicJsonType::string_t> {}(element.key());
+                const auto h = std::hash<string_t> {}(element.key());
                 seed = combine(seed, h);
                 seed = combine(seed, hash(element.value()));
             }
@@ -4492,7 +4497,7 @@ std::size_t hash(const BasicJsonType& j)
 
         case BasicJsonType::value_t::string:
         {
-            const auto h = std::hash<typename BasicJsonType::string_t> {}(j.template get_ref<const typename BasicJsonType::string_t&>());
+            const auto h = std::hash<string_t> {}(j.template get_ref<const string_t&>());
             return combine(static_cast<std::size_t>(j.type()), h);
         }
 
@@ -4504,25 +4509,27 @@ std::size_t hash(const BasicJsonType& j)
 
         case BasicJsonType::value_t::number_integer:
         {
-            const auto h = std::hash<typename BasicJsonType::number_integer_t> {}(j.template get<typename BasicJsonType::number_integer_t>());
+            const auto h = std::hash<number_integer_t> {}(j.template get<number_integer_t>());
             return combine(static_cast<std::size_t>(j.type()), h);
         }
 
         case nlohmann::detail::value_t::number_unsigned:
         {
-            const auto h = std::hash<typename BasicJsonType::number_unsigned_t> {}(j.template get<typename BasicJsonType::number_unsigned_t>());
+            const auto h = std::hash<number_unsigned_t> {}(j.template get<number_unsigned_t>());
             return combine(static_cast<std::size_t>(j.type()), h);
         }
 
         case nlohmann::detail::value_t::number_float:
         {
-            const auto h = std::hash<typename BasicJsonType::number_float_t> {}(j.template get<typename BasicJsonType::number_float_t>());
+            const auto h = std::hash<number_float_t> {}(j.template get<number_float_t>());
             return combine(static_cast<std::size_t>(j.type()), h);
         }
 
         case nlohmann::detail::value_t::binary:
         {
             auto seed = combine(static_cast<std::size_t>(j.type()), j.get_binary().size());
+            const auto h = std::hash<bool> {}(j.get_binary().has_subtype());
+            seed = combine(seed, h);
             seed = combine(seed, j.get_binary().subtype());
             for (const auto byte : j.get_binary())
             {
@@ -4530,9 +4537,10 @@ std::size_t hash(const BasicJsonType& j)
             }
             return seed;
         }
-    }
 
-    return 0;
+        default: // LCOV_EXCL_LINE
+            JSON_ASSERT(false); // LCOV_EXCL_LINE
+    }
 }
 
 }  // namespace detail

test/CMakeLists.txt

@@ -112,6 +112,7 @@ set(files
     src/unit-deserialization.cpp
     src/unit-element_access1.cpp
     src/unit-element_access2.cpp
+    src/unit-hash.cpp
     src/unit-inspection.cpp
     src/unit-items.cpp
     src/unit-iterators1.cpp

test/Makefile

@@ -10,6 +10,7 @@ SOURCES = src/unit.cpp \
           src/unit-algorithms.cpp \
           src/unit-allocator.cpp \
           src/unit-alt-string.cpp \
+		  src/unit-assert_macro.cpp \
           src/unit-bson.cpp \
           src/unit-capacity.cpp \
           src/unit-cbor.cpp \

test/src/unit-hash.cpp

@@ -0,0 +1,90 @@
+/*
+    __ _____ _____ _____
+ __|  |   __|     |   | |  JSON for Modern C++ (test suite)
+|  |  |__   |  |  | | | |  version 3.8.0
+|_____|_____|_____|_|___|  https://github.com/nlohmann/json
+
+Licensed under the MIT License <http://opensource.org/licenses/MIT>.
+SPDX-License-Identifier: MIT
+Copyright (c) 2013-2019 Niels Lohmann <http://nlohmann.me>.
+
+Permission is hereby  granted, free of charge, to any  person obtaining a copy
+of this software and associated  documentation files (the "Software"), to deal
+in the Software  without restriction, including without  limitation the rights
+to  use, copy,  modify, merge,  publish, distribute,  sublicense, and/or  sell
+copies  of  the Software,  and  to  permit persons  to  whom  the Software  is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE  IS PROVIDED "AS  IS", WITHOUT WARRANTY  OF ANY KIND,  EXPRESS OR
+IMPLIED,  INCLUDING BUT  NOT  LIMITED TO  THE  WARRANTIES OF  MERCHANTABILITY,
+FITNESS FOR  A PARTICULAR PURPOSE AND  NONINFRINGEMENT. IN NO EVENT  SHALL THE
+AUTHORS  OR COPYRIGHT  HOLDERS  BE  LIABLE FOR  ANY  CLAIM,  DAMAGES OR  OTHER
+LIABILITY, WHETHER IN AN ACTION OF  CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE  OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+*/
+
+#include "doctest_compatibility.h"
+
+#include <nlohmann/json.hpp>
+using json = nlohmann::json;
+
+TEST_CASE("hash")
+{
+    SECTION("null")
+    {
+        CHECK(std::hash<json> {}(json(nullptr)) == 2654435769U);
+    }
+
+    SECTION("boolean")
+    {
+        CHECK(std::hash<json> {}(json(true)) == 2654436031U);
+        CHECK(std::hash<json> {}(json(false)) == 2654436030U);
+    }
+
+    SECTION("string")
+    {
+        CHECK(std::hash<json> {}(json("")) == 11160318156688833227U);
+        CHECK(std::hash<json> {}(json("foo")) == 910203211069189493U);
+    }
+
+    SECTION("number")
+    {
+        CHECK(std::hash<json> {}(json(int(0))) == 2654436095U);
+        CHECK(std::hash<json> {}(json(unsigned(0))) == 2654436156U);
+
+        CHECK(std::hash<json> {}(json(-1)) == 2654436092U);
+        CHECK(std::hash<json> {}(json(0.0)) == 2654436221U);
+        CHECK(std::hash<json> {}(json(42.23)) == 4631140164097181104U);
+    }
+
+    SECTION("array")
+    {
+        CHECK(std::hash<json> {}(json::array()) == 2654435899U);
+        CHECK(std::hash<json> {}(json::array({1, 2, 3})) == 717272658337467U);
+    }
+
+    SECTION("object")
+    {
+        CHECK(std::hash<json> {}(json::object()) == 2654435832U);
+        CHECK(std::hash<json> {}(json::object({{"foo", "bar"}})) == 4042265434648078139U);
+    }
+
+    SECTION("binary")
+    {
+        CHECK(std::hash<json> {}(json::binary({})) == 11093832941624U);
+        CHECK(std::hash<json> {}(json::binary({}, 0)) == 11093832941691U);
+        CHECK(std::hash<json> {}(json::binary({}, 42)) == 11093832941581U);
+        CHECK(std::hash<json> {}(json::binary({1, 2, 3})) == 3005324138949694928U);
+        CHECK(std::hash<json> {}(json::binary({1, 2, 3}, 0)) == 3005324138988516582U);
+        CHECK(std::hash<json> {}(json::binary({1, 2, 3}, 42)) == 3005324138986241627U);
+    }
+
+    SECTION("discarded")
+    {
+        CHECK(std::hash<json> {}(json(json::value_t::discarded)) == 2654436338U);
+    }
+}