test(byteswap): adding deeper unit testing

Found a glitch during ESP-IDF testing

test/arduino/unity/test/test_embedded/test_main.cpp

@@ -58,6 +58,7 @@ void setup()
     test_avr_pgm();
 #endif
     test_bipbuf();
+    test_bit();
     test_chrono();
     test_cpp();
     test_cstddef();

test/catch/bit-test.cpp

@@ -17,6 +17,10 @@ TEST_CASE("bit operations")
             auto v = estd::byteswap<int32_t>(0x1234);
 
             REQUIRE(v == 0x34120000);
+
+            auto v1 = estd::byteswap<int32_t>(-500);
+
+            REQUIRE(estd::byteswap(v1) == -500);
         }
     }
 }

test/unity/bit.cpp

@@ -0,0 +1,16 @@
+#include <estd/bit.h>
+
+#include "unit-test.h"
+
+#ifdef ESP_IDF_TESTING
+TEST_CASE("bit/endian tests", "[bit]")
+#else
+void test_bit()
+#endif
+{
+    auto vu16 = estd::byteswap<uint16_t>(0x1234);
+    auto vi32 = estd::byteswap<int32_t>(-500);
+
+    TEST_ASSERT_EQUAL(0x3421, vu16);
+    TEST_ASSERT_EQUAL(-500, estd::byteswap(vi32));
+}

test/unity/unit-test.h

@@ -19,6 +19,7 @@ void test_align();
 void test_array();
 void test_avr_pgm();
 void test_bipbuf();
+void test_bit();
 void test_cpp();
 void test_chrono();
 void test_cstddef();