Fixed too many decimals places in float serialization (issue #543)

test/Misc/FloatParts.cpp

@@ -0,0 +1,47 @@
+// Copyright Benoit Blanchon 2014-2017
+// MIT License
+//
+// Arduino JSON library
+// https://bblanchon.github.io/ArduinoJson/
+// If you like this project, please add a star!
+
+#include <ArduinoJson/Serialization/FloatParts.hpp>
+#include <catch.hpp>
+
+using namespace ArduinoJson::Internals;
+
+TEST_CASE("FloatParts<double>") {
+  SECTION("1.7976931348623157E+308") {
+    FloatParts<double> parts(1.7976931348623157E+308);
+    REQUIRE(parts.integral == 1);
+    REQUIRE(parts.decimal == 797693135);
+    REQUIRE(parts.decimalPlaces == 9);
+    REQUIRE(parts.exponent == 308);
+  }
+
+  SECTION("4.94065645841247e-324") {
+    FloatParts<double> parts(4.94065645841247e-324);
+    REQUIRE(parts.integral == 4);
+    REQUIRE(parts.decimal == 940656458);
+    REQUIRE(parts.decimalPlaces == 9);
+    REQUIRE(parts.exponent == -324);
+  }
+}
+
+TEST_CASE("FloatParts<float>") {
+  SECTION("3.4E+38") {
+    FloatParts<float> parts(3.4E+38f);
+    REQUIRE(parts.integral == 3);
+    REQUIRE(parts.decimal == 4);
+    REQUIRE(parts.decimalPlaces == 1);
+    REQUIRE(parts.exponent == 38);
+  }
+
+  SECTION("1.17549435e−38") {
+    FloatParts<float> parts(1.17549435e-38f);
+    REQUIRE(parts.integral == 1);
+    REQUIRE(parts.decimal == 175494);
+    REQUIRE(parts.decimalPlaces == 6);
+    REQUIRE(parts.exponent == -38);
+  }
+}