LibGLSL: Add tests for GLSL parser

Tests/LibGLSL/test-parser.cpp

@@ -0,0 +1,61 @@
+/*
+ * Copyright (c) 2021, Itamar S. <itamar8910@gmail.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <AK/LexicalPath.h>
+#include <AK/MemoryStream.h>
+#include <LibCore/Directory.h>
+#include <LibCore/File.h>
+#include <LibGLSL/Parser.h>
+#include <LibTest/TestCase.h>
+
+constexpr StringView TESTS_ROOT_DIR = "/home/anon/Tests/glsl-tests/parser"sv;
+
+static String read_all(String const& path)
+{
+    auto file = MUST(Core::File::open(path, Core::File::OpenMode::Read));
+    auto file_size = MUST(file->size());
+    return MUST(String::from_stream(*file, file_size));
+}
+
+TEST_CASE(test_regression)
+{
+    MUST(Core::Directory::for_each_entry(TESTS_ROOT_DIR, Core::DirIterator::Flags::SkipDots, [](auto const& entry, auto const& directory) -> ErrorOr<IterationDecision> {
+        auto path = LexicalPath::join(directory.path().string(), entry.name);
+        if (!path.has_extension(".glsl"sv))
+            return IterationDecision::Continue;
+
+        outln("Checking {}...", path.basename());
+        String file_path = MUST(String::from_deprecated_string(path.string()));
+
+        auto ast_file_path = MUST(String::formatted("{}.ast", MUST(file_path.substring_from_byte_offset(0, file_path.bytes_as_string_view().length() - sizeof(".glsl") + 1))));
+
+        auto source = read_all(file_path);
+        auto target_ast = read_all(ast_file_path);
+
+        GLSL::Preprocessor preprocessor(file_path, source);
+        GLSL::Parser parser(MUST(preprocessor.process_and_lex()), file_path);
+        auto root = MUST(parser.parse());
+
+        EXPECT(parser.errors().is_empty());
+
+        Vector<uint8_t> memory;
+        memory.resize(8 * 1024 * 1024);
+        AK::FixedMemoryStream output_stream(memory.span());
+
+        MUST(root->dump(output_stream));
+
+        auto written_bytes = MUST(output_stream.tell());
+        MUST(output_stream.seek(0));
+
+        String content = MUST(String::from_stream(output_stream, written_bytes));
+
+        auto equal = content == target_ast;
+        EXPECT(equal);
+        if (!equal)
+            outln("Failed on {}", path.basename());
+        return IterationDecision::Continue;
+    }));
+}