Added tests for SwapChannels

Test/SwapChannels.cpp

@@ -0,0 +1,83 @@
+#include <Bmp.h>
+#include <stdexcept>
+#include "Catch2.h"
+
+using namespace Leonetienne::BmpPP;
+using namespace Eule;
+
+// Tests that swapping channels works
+TEST_CASE(__FILE__"/SwappingChannelsWorks", "[SwapChannels]")
+{
+    SECTION("R2G") {
+        // Read an image
+        BMP bmp("base_fuwadera.bmp");
+
+        // Swap channels
+        bmp.SwapChannels(0, 1);
+
+        // Read reference image
+        const BMP reference("base_fuwadera_channelswap_rg.bmp");
+
+        // Assert that they are equal
+        REQUIRE(bmp == reference);
+    }
+
+    SECTION("R2B") {
+        // Read an image
+        BMP bmp("base_fuwadera.bmp");
+
+        // Swap channels
+        bmp.SwapChannels(0, 2);
+
+        // Read reference image
+        const BMP reference("base_fuwadera_channelswap_rb.bmp");
+
+        // Assert that they are equal
+        REQUIRE(bmp == reference);
+    }
+
+    SECTION("G2B") {
+        // Read an image
+        BMP bmp("base_fuwadera.bmp");
+
+        // Swap channels
+        bmp.SwapChannels(1, 2);
+
+        // Read reference image
+        const BMP reference("base_fuwadera_channelswap_gb.bmp");
+
+        // Assert that they are equal
+        REQUIRE(bmp == reference);
+    }
+
+    return;
+}
+
+// Tests that swapping selecting a color channel that's out of range produces a runtime error
+TEST_CASE(__FILE__"/RuntimeError_on_channel_out_of_range", "[SwapChannels]")
+{
+    SECTION("RGB_OUT_OF_RANGE") {
+        BMP bmp(Vector2i(800, 600), Colormode::RGB);
+
+        REQUIRE_THROWS_AS(
+            bmp.SwapChannels(0, 3)
+            , std::runtime_error
+        );
+    }
+
+    SECTION("RGBA_OK") {
+        BMP bmp(Vector2i(800, 600), Colormode::RGBA);
+
+        bmp.SwapChannels(0, 3);
+    }
+
+    SECTION("RGBA_OUT_OF_RANGE") {
+        BMP bmp(Vector2i(800, 600), Colormode::RGBA);
+
+        REQUIRE_THROWS_AS(
+                bmp.SwapChannels(0, 4)
+        , std::runtime_error
+        );
+    }
+    return;
+}