Fixed error in float serialization (issue #324)

test/JsonWriter_WriteFloat_Tests.cpp

@@ -0,0 +1,113 @@
+// Copyright Benoit Blanchon 2014-2016
+// MIT License
+//
+// Arduino JSON library
+// https://github.com/bblanchon/ArduinoJson
+// If you like this project, please add a star!
+
+#include <gtest/gtest.h>
+#include <limits>
+
+#include <ArduinoJson/Internals/JsonWriter.hpp>
+#include <ArduinoJson/Internals/StaticStringBuilder.hpp>
+
+using namespace ArduinoJson::Internals;
+
+class JsonWriter_WriteFloat_Tests : public testing::Test {
+ protected:
+  void whenInputIs(double input, uint8_t digits = 2) {
+    StaticStringBuilder sb(buffer, sizeof(buffer));
+    JsonWriter writer(sb);
+    writer.writeFloat(input, digits);
+    returnValue = writer.bytesWritten();
+  }
+
+  void outputMustBe(const char *expected) {
+    EXPECT_STREQ(expected, buffer);
+    EXPECT_EQ(strlen(expected), returnValue);
+  }
+
+ private:
+  char buffer[1024];
+  size_t returnValue;
+};
+
+TEST_F(JsonWriter_WriteFloat_Tests, NaN) {
+  whenInputIs(std::numeric_limits<double>::signaling_NaN());
+  outputMustBe("NaN");
+}
+
+TEST_F(JsonWriter_WriteFloat_Tests, PositiveInfinity) {
+  whenInputIs(std::numeric_limits<double>::infinity());
+  outputMustBe("Infinity");
+}
+
+TEST_F(JsonWriter_WriteFloat_Tests, NegativeInfinity) {
+  whenInputIs(-std::numeric_limits<double>::infinity());
+  outputMustBe("-Infinity");
+}
+
+TEST_F(JsonWriter_WriteFloat_Tests, Zero) {
+  whenInputIs(0);
+  outputMustBe("0.00");
+}
+
+TEST_F(JsonWriter_WriteFloat_Tests, ZeroDigits_Rounding) {
+  whenInputIs(9.5, 0);
+  outputMustBe("10");
+}
+
+TEST_F(JsonWriter_WriteFloat_Tests, ZeroDigits_NoRounding) {
+  whenInputIs(9.4, 0);
+  outputMustBe("9");
+}
+
+TEST_F(JsonWriter_WriteFloat_Tests, OneDigit_Rounding) {
+  whenInputIs(9.95, 1);
+  outputMustBe("10.0");
+}
+
+TEST_F(JsonWriter_WriteFloat_Tests, OneDigit_NoRounding) {
+  whenInputIs(9.94, 1);
+  outputMustBe("9.9");
+}
+
+TEST_F(JsonWriter_WriteFloat_Tests, TwoDigits_Rounding) {
+  whenInputIs(9.995, 2);
+  outputMustBe("10.00");
+}
+
+TEST_F(JsonWriter_WriteFloat_Tests, TwoDigits_NoRounding) {
+  whenInputIs(9.994, 2);
+  outputMustBe("9.99");
+}
+
+TEST_F(JsonWriter_WriteFloat_Tests, ThreeDigits_Rounding) {
+  whenInputIs(9.9995, 3);
+  outputMustBe("10.000");
+}
+
+TEST_F(JsonWriter_WriteFloat_Tests, ThreeDigits_NoRounding) {
+  whenInputIs(9.9994, 3);
+  outputMustBe("9.999");
+}
+
+TEST_F(JsonWriter_WriteFloat_Tests, FourDigits_Rounding) {
+  whenInputIs(9.99995, 4);
+  outputMustBe("10.0000");
+}
+
+TEST_F(JsonWriter_WriteFloat_Tests, FourDigits_NoRounding) {
+  whenInputIs(9.99994, 4);
+  outputMustBe("9.9999");
+}
+
+TEST_F(JsonWriter_WriteFloat_Tests, FiveDigits_Rounding) {
+  whenInputIs(9.999995, 5);
+  outputMustBe("10.00000");
+}
+
+TEST_F(JsonWriter_WriteFloat_Tests, FiveDigits_NoRounding) {
+  whenInputIs(9.999994, 5);
+  outputMustBe("9.99999");
+}