Adding test code for 'RingbufferN::clear'

Author: aentinger

Diff for: test/CMakeLists.txt

@@ -29,6 +29,7 @@ set(TEST_SRCS
   src/Common/test_min.cpp
   src/Ringbuffer/test_available.cpp
   src/Ringbuffer/test_availableForStore.cpp
+  src/Ringbuffer/test_clear.cpp
   src/Ringbuffer/test_isFull.cpp
   src/WCharacter/test_isControl.cpp
   src/WCharacter/test_isDigit.cpp

Diff for: test/src/Ringbuffer/test_clear.cpp

@@ -0,0 +1,32 @@
+/*
+ * Copyright (c) 2020 Arduino.  All rights reserved.
+ */
+
+/**************************************************************************************
+ * INCLUDE
+ **************************************************************************************/
+
+#include <catch.hpp>
+
+#include <RingBuffer.h>
+
+/**************************************************************************************
+ * TEST CODE
+ **************************************************************************************/
+
+TEST_CASE ("Calling 'clear' on a empty ring buffer should have no effect", "[Ringbuffer-clear-01]")
+{
+  arduino::RingBufferN<2> ringbuffer;
+  REQUIRE(ringbuffer.available() == 0);
+  ringbuffer.clear();
+  REQUIRE(ringbuffer.available() == 0);
+}
+
+TEST_CASE ("Calling 'clear' on a partially filled ring buffer should \"remove\" all elements", "[Ringbuffer-clear-02]")
+{
+  arduino::RingBufferN<2> ringbuffer;
+  ringbuffer.store_char('A');
+  REQUIRE(ringbuffer.available() == 1);
+  ringbuffer.clear();
+  REQUIRE(ringbuffer.available() == 0);
+}