diff --git a/tests/test_main.cpp b/tests/test_main.cpp
index 0fb9f2fcda0..84d2fe1f6c8 100644
--- a/tests/test_main.cpp
+++ b/tests/test_main.cpp
@@ -48,6 +48,7 @@
 #include "test_shader_lang.h"
 #include "test_string.h"
 #include "test_validate_testing.h"
+#include "test_variant.h"
 
 #include "modules/modules_tests.gen.h"
 
diff --git a/tests/test_variant.h b/tests/test_variant.h
new file mode 100644
index 00000000000..06dcfde6643
--- /dev/null
+++ b/tests/test_variant.h
@@ -0,0 +1,111 @@
+/*************************************************************************/
+/*  test_variant.h                                                       */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2020 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2020 Godot Engine contributors (cf. AUTHORS.md).   */
+/*                                                                       */
+/* 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.                */
+/*************************************************************************/
+
+#ifndef TEST_VARIANT_H
+#define TEST_VARIANT_H
+
+#include "core/variant.h"
+#include "core/variant_parser.h"
+
+#include "thirdparty/doctest/doctest.h"
+
+namespace TestVariant {
+
+TEST_CASE("[Variant] Writer and parser integer") {
+	int64_t a32 = 2147483648; // 2^31, so out of bounds for 32-bit signed int [-2^31,-2^31-1].
+	String a32_str;
+	VariantWriter::write_to_string(a32, a32_str);
+
+	CHECK_MESSAGE(a32_str != "-2147483648", "Should not wrap around");
+
+	int64_t b64 = 9223372036854775807; // 2^63-1, upper bound for signed 64-bit int.
+	String b64_str;
+	VariantWriter::write_to_string(b64, b64_str);
+
+	CHECK_MESSAGE(b64_str == "9223372036854775807", "Should not wrap around.");
+
+	VariantParser::StreamString ss;
+	String errs;
+	int line;
+	Variant b64_parsed;
+	int64_t b64_int_parsed;
+
+	ss.s = b64_str;
+	VariantParser::parse(&ss, b64_parsed, errs, line);
+	b64_int_parsed = b64_parsed;
+
+	CHECK_MESSAGE(b64_int_parsed == 9223372036854775807, "Should parse back.");
+
+	ss.s = "9223372036854775808"; // Overflowed by one.
+	VariantParser::parse(&ss, b64_parsed, errs, line);
+	b64_int_parsed = b64_parsed;
+
+	CHECK_MESSAGE(b64_int_parsed == 9223372036854775807, "The result should be clamped to max value.");
+
+	ss.s = "1e100"; // Googol! Scientific notation.
+	VariantParser::parse(&ss, b64_parsed, errs, line);
+	b64_int_parsed = b64_parsed;
+
+	CHECK_MESSAGE(b64_int_parsed == 9223372036854775807, "The result should be clamped to max value.");
+}
+
+TEST_CASE("[Variant] Writer and parser float") {
+	// Assuming real_t is double.
+	real_t a64 = 340282346638528859811704183484516925440.0; // std::numeric_limits<real_t>::max()
+	String a64_str;
+	VariantWriter::write_to_string(a64, a64_str);
+
+	CHECK_MESSAGE(a64_str == "3.40282e+38", "Writes in scientific notation.");
+	CHECK_MESSAGE(a64_str != "inf", "Should not overflow.");
+	CHECK_MESSAGE(a64_str != "nan", "The result should be defined.");
+
+	VariantParser::StreamString ss;
+	String errs;
+	int line;
+	Variant b64_parsed;
+	real_t b64_float_parsed;
+
+	ss.s = a64_str;
+	VariantParser::parse(&ss, b64_parsed, errs, line);
+	b64_float_parsed = b64_parsed;
+
+	CHECK_MESSAGE(b64_float_parsed == 340282001837565597733306976381245063168.0, "Should parse back.");
+	// Loses precision, but that's alright.
+
+	ss.s = "1.0e+100"; // Float version of Googol!
+	VariantParser::parse(&ss, b64_parsed, errs, line);
+	b64_float_parsed = b64_parsed;
+
+	CHECK_MESSAGE(b64_float_parsed == 340282001837565597733306976381245063168.0, "Should not overflow.");
+}
+
+} // namespace TestVariant
+
+#endif // TEST_VARIANT_H