Tests/LibGfx: Consolidate jbig2 decode tests

Removes some duplication, and makes it easier to add additional tests.
No behavior change.

Tests/LibGfx/TestImageDecoder.cpp

@@ -336,38 +336,28 @@ TEST_CASE(test_jbig2_white_47x23)
         EXPECT_EQ(pixel, Gfx::Color(Gfx::Color::White).value());
 }
 
-TEST_CASE(test_jbig2_generic_region_arithmetic_code)
+TEST_CASE(test_jbig2_decode)
 {
-    auto file = TRY_OR_FAIL(Core::MappedFile::map(TEST_INPUT("jbig2/bitmap.jbig2"sv)));
-    EXPECT(Gfx::JBIG2ImageDecoderPlugin::sniff(file->bytes()));
-    auto plugin_decoder = TRY_OR_FAIL(Gfx::JBIG2ImageDecoderPlugin::create(file->bytes()));
-
     auto bmp_file = TRY_OR_FAIL(Core::MappedFile::map(TEST_INPUT("bmp/bitmap.bmp"sv)));
     auto bmp_plugin_decoder = TRY_OR_FAIL(Gfx::BMPImageDecoderPlugin::create(bmp_file->bytes()));
-
-    auto frame = TRY_OR_FAIL(expect_single_frame_of_size(*plugin_decoder, { 399, 400 }));
     auto bmp_frame = TRY_OR_FAIL(expect_single_frame_of_size(*bmp_plugin_decoder, { 399, 400 }));
 
-    for (int y = 0; y < frame.image->height(); ++y)
-        for (int x = 0; x < frame.image->width(); ++x)
-            EXPECT_EQ(frame.image->get_pixel(x, y), bmp_frame.image->get_pixel(x, y));
-}
-
-TEST_CASE(test_jbig2_generic_region_arithmetic_code_tpgdon)
-{
-    auto file = TRY_OR_FAIL(Core::MappedFile::map(TEST_INPUT("jbig2/bitmap-tpgdon.jbig2"sv)));
-    EXPECT(Gfx::JBIG2ImageDecoderPlugin::sniff(file->bytes()));
-    auto plugin_decoder = TRY_OR_FAIL(Gfx::JBIG2ImageDecoderPlugin::create(file->bytes()));
+    Array test_inputs = {
+        TEST_INPUT("jbig2/bitmap.jbig2"sv),
+        TEST_INPUT("jbig2/bitmap-tpgdon.jbig2"sv),
+    };
 
-    auto bmp_file = TRY_OR_FAIL(Core::MappedFile::map(TEST_INPUT("bmp/bitmap.bmp"sv)));
-    auto bmp_plugin_decoder = TRY_OR_FAIL(Gfx::BMPImageDecoderPlugin::create(bmp_file->bytes()));
+    for (auto test_input : test_inputs) {
+        auto file = TRY_OR_FAIL(Core::MappedFile::map(test_input));
+        EXPECT(Gfx::JBIG2ImageDecoderPlugin::sniff(file->bytes()));
+        auto plugin_decoder = TRY_OR_FAIL(Gfx::JBIG2ImageDecoderPlugin::create(file->bytes()));
 
-    auto frame = TRY_OR_FAIL(expect_single_frame_of_size(*plugin_decoder, { 399, 400 }));
-    auto bmp_frame = TRY_OR_FAIL(expect_single_frame_of_size(*bmp_plugin_decoder, { 399, 400 }));
+        auto frame = TRY_OR_FAIL(expect_single_frame_of_size(*plugin_decoder, { 399, 400 }));
 
-    for (int y = 0; y < frame.image->height(); ++y)
-        for (int x = 0; x < frame.image->width(); ++x)
-            EXPECT_EQ(frame.image->get_pixel(x, y), bmp_frame.image->get_pixel(x, y));
+        for (int y = 0; y < frame.image->height(); ++y)
+            for (int x = 0; x < frame.image->width(); ++x)
+                EXPECT_EQ(frame.image->get_pixel(x, y), bmp_frame.image->get_pixel(x, y));
+    }
 }
 
 TEST_CASE(test_jbig2_arithmetic_decoder)