fix userver: fix double to float conversion for 'Value' classes

Relates: <https://nda.ya.ru/t/Dx1JoAAr7M6sew>
commit_hash:62bb808e44373deaf2d19bda87f72a92c6072f35

Author: pananton

universal/include/userver/formats/parse/common.hpp

@@ -7,6 +7,7 @@
 /// @ingroup userver_universal userver_formats_parse
 
 #include <chrono>
+#include <cmath>
 #include <cstdint>
 #include <limits>
 
@@ -34,9 +35,25 @@ void CheckInBounds(const Value& value, T x, T min, T max) {
     }
 }
 
+template <typename Value>
+void CheckDoubleFitsInFloat(const Value& value, const double dval) {
+    if (std::isinf(dval) || std::isnan(dval)) {
+        // double infinity and NaN are directly convertible to float infinity and NaN
+        return;
+    }
+
+    auto fval = static_cast<float>(dval);
+
+    if (!std::isfinite(fval)) {
+        throw typename Value::ParseException(
+            fmt::format("Double value ({}) of '{}' does not fit into float", dval, value.GetPath())
+        );
+    }
+}
+
 template <typename Value>
 float NarrowToFloat(double x, const Value& value) {
-    CheckInBounds<double>(value, x, std::numeric_limits<float>::lowest(), std::numeric_limits<float>::max());
+    CheckDoubleFitsInFloat(value, x);
     return static_cast<float>(x);
 }
 

universal/src/formats/common/value_test.hpp

@@ -1,12 +1,16 @@
+#include <userver/formats/common/type.hpp>
 #include <userver/formats/parse/boost_flat_containers.hpp>
 #include <userver/formats/parse/boost_optional.hpp>
 #include <userver/formats/parse/time_of_day.hpp>
 #include <userver/formats/parse/to.hpp>
 #include <userver/formats/parse/variant.hpp>
+#include <userver/utils/meta_light.hpp>
 
+#include <limits>
 #include <map>
 #include <optional>
 #include <set>
+#include <stdexcept>
 #include <string>
 #include <unordered_map>
 #include <unordered_set>
@@ -199,6 +203,23 @@ TYPED_TEST_P(Parsing, IntOverflow) {
     EXPECT_EQ(65535, value.template As<uint16_t>());
 }
 
+TYPED_TEST_P(Parsing, MaxMinFloat) {
+    using Value = std::decay_t<decltype(this->kFromString(""))>;
+
+    constexpr float kFloatMax = std::numeric_limits<float>::max();
+    constexpr float kFloatMin = std::numeric_limits<float>::min();
+
+    auto float_max = this->kFromString(fmt::format("[{}]", kFloatMax))[0];
+    auto float_negative_max = this->kFromString(fmt::format("[{}]", -kFloatMax))[0];
+    auto float_min = this->kFromString(fmt::format("[{}]", kFloatMin))[0];
+    auto float_negative_min = this->kFromString(fmt::format("[{}]", -kFloatMin))[0];
+
+    EXPECT_EQ(float_max.template As<float>(), kFloatMax);
+    EXPECT_EQ(float_negative_max.template As<float>(), -kFloatMax);
+    EXPECT_EQ(float_min.template As<float>(), kFloatMin);
+    EXPECT_EQ(float_negative_min.template As<float>(), -kFloatMin);
+}
+
 TYPED_TEST_P(Parsing, UserProvidedCommonParser) {
     auto value = this->kFromString("[42]")[0];
 
@@ -372,6 +393,7 @@ REGISTER_TYPED_TEST_SUITE_P(
     Int,
     UInt,
     IntOverflow,
+    MaxMinFloat,
     UserProvidedCommonParser,
 
     ChronoDoubleSeconds,