Start assets component image signature tests

tests/assets/image_format_tests.cpp

@@ -0,0 +1,88 @@
+#include "assets/image_format.h"
+#include "test_harness.h"
+
+#include <array>
+#include <cstddef>
+#include <string_view>
+
+using pp::assets::ImageFormat;
+using pp::assets::detect_image_format;
+using pp::assets::image_format_name;
+using pp::foundation::StatusCode;
+
+namespace {
+
+void detects_png_and_jpeg_signatures(pp::tests::Harness& h)
+{
+    constexpr std::array png {
+        std::byte { 0x89 },
+        std::byte { 0x50 },
+        std::byte { 0x4e },
+        std::byte { 0x47 },
+        std::byte { 0x0d },
+        std::byte { 0x0a },
+        std::byte { 0x1a },
+        std::byte { 0x0a },
+        std::byte { 0x00 },
+    };
+    constexpr std::array jpeg {
+        std::byte { 0xff },
+        std::byte { 0xd8 },
+        std::byte { 0xff },
+        std::byte { 0xe0 },
+    };
+
+    const auto png_format = detect_image_format(png);
+    const auto jpeg_format = detect_image_format(jpeg);
+
+    PP_EXPECT(h, png_format.ok());
+    PP_EXPECT(h, png_format.value() == ImageFormat::png);
+    PP_EXPECT(h, image_format_name(png_format.value()) == std::string_view("png"));
+    PP_EXPECT(h, jpeg_format.ok());
+    PP_EXPECT(h, jpeg_format.value() == ImageFormat::jpeg);
+    PP_EXPECT(h, image_format_name(jpeg_format.value()) == std::string_view("jpeg"));
+}
+
+void rejects_empty_truncated_and_unsupported_inputs(pp::tests::Harness& h)
+{
+    constexpr std::array<std::byte, 0> empty {};
+    constexpr std::array partial_png {
+        std::byte { 0x89 },
+        std::byte { 0x50 },
+        std::byte { 0x4e },
+    };
+    constexpr std::array short_unknown {
+        std::byte { 0x12 },
+        std::byte { 0x34 },
+    };
+    constexpr std::array unsupported {
+        std::byte { 0x47 },
+        std::byte { 0x49 },
+        std::byte { 0x46 },
+        std::byte { 0x38 },
+    };
+
+    const auto empty_result = detect_image_format(empty);
+    const auto partial_png_result = detect_image_format(partial_png);
+    const auto short_result = detect_image_format(short_unknown);
+    const auto unsupported_result = detect_image_format(unsupported);
+
+    PP_EXPECT(h, !empty_result.ok());
+    PP_EXPECT(h, empty_result.status().code == StatusCode::invalid_argument);
+    PP_EXPECT(h, !partial_png_result.ok());
+    PP_EXPECT(h, partial_png_result.status().code == StatusCode::out_of_range);
+    PP_EXPECT(h, !short_result.ok());
+    PP_EXPECT(h, short_result.status().code == StatusCode::out_of_range);
+    PP_EXPECT(h, !unsupported_result.ok());
+    PP_EXPECT(h, unsupported_result.status().code == StatusCode::invalid_argument);
+}
+
+}
+
+int main()
+{
+    pp::tests::Harness harness;
+    harness.run("detects_png_and_jpeg_signatures", detects_png_and_jpeg_signatures);
+    harness.run("rejects_empty_truncated_and_unsupported_inputs", rejects_empty_truncated_and_unsupported_inputs);
+    return harness.finish();
+}