add Symbol class unit tests

tests/test_symbol.cpp

@@ -0,0 +1,99 @@
+#include <catch2/catch_test_macros.hpp>
+#include "../src/symbol.hpp"
+#include <fcntl.h>
+#include <unistd.h>
+#include <filesystem>
+
+TEST_CASE("VarInfo struct construction", "[symbol]") {
+    VarInfo info{"test_var", 0x1000, 4};
+
+    REQUIRE(info.name == "test_var");
+    REQUIRE(info.address == 0x1000);
+    REQUIRE(info.size == 4);
+}
+
+TEST_CASE("VarInfo struct with different sizes", "[symbol]") {
+    SECTION("1 byte variable") {
+        VarInfo info{"char_var", 0x2000, 1};
+        REQUIRE(info.size == 1);
+    }
+
+    SECTION("2 byte variable") {
+        VarInfo info{"short_var", 0x2000, 2};
+        REQUIRE(info.size == 2);
+    }
+
+    SECTION("4 byte variable") {
+        VarInfo info{"int_var", 0x2000, 4};
+        REQUIRE(info.size == 4);
+    }
+
+    SECTION("8 byte variable") {
+        VarInfo info{"long_var", 0x2000, 8};
+        REQUIRE(info.size == 8);
+    }
+}
+
+TEST_CASE("Symbol class finds global variables in test binary", "[symbol][integration]") {
+    // Use the test_access binary if it exists
+    std::filesystem::path test_binary = "./test_access";
+
+    if (!std::filesystem::exists(test_binary)) {
+        WARN("test_access binary not found, skipping integration test");
+        return;
+    }
+
+    int fd = open(test_binary.c_str(), O_RDONLY);
+    REQUIRE(fd >= 0);
+
+    Dwarf_Debug dbg = nullptr;
+    Dwarf_Error err;
+    int res = dwarf_init_b(fd, DW_GROUPNUMBER_ANY, nullptr, nullptr, &dbg, &err);
+
+    if (res != DW_DLV_OK) {
+        close(fd);
+        WARN("Failed to initialize DWARF for test_access, skipping test");
+        return;
+    }
+
+    Symbol symbol;
+    auto var_info = symbol.find_global_var(dbg, "global_counter");
+
+    dwarf_finish(dbg);
+    close(fd);
+
+    REQUIRE(var_info.has_value());
+    REQUIRE(var_info->name == "global_counter");
+    REQUIRE(var_info->size > 0);
+    REQUIRE(var_info->size <= 8);
+}
+
+TEST_CASE("Symbol class returns nullopt for non-existent variable", "[symbol][integration]") {
+    std::filesystem::path test_binary = "./test_access";
+
+    if (!std::filesystem::exists(test_binary)) {
+        WARN("test_access binary not found, skipping integration test");
+        return;
+    }
+
+    int fd = open(test_binary.c_str(), O_RDONLY);
+    REQUIRE(fd >= 0);
+
+    Dwarf_Debug dbg = nullptr;
+    Dwarf_Error err;
+    int res = dwarf_init_b(fd, DW_GROUPNUMBER_ANY, nullptr, nullptr, &dbg, &err);
+
+    if (res != DW_DLV_OK) {
+        close(fd);
+        WARN("Failed to initialize DWARF for test_access, skipping test");
+        return;
+    }
+
+    Symbol symbol;
+    auto var_info = symbol.find_global_var(dbg, "nonexistent_variable_xyz");
+
+    dwarf_finish(dbg);
+    close(fd);
+
+    REQUIRE_FALSE(var_info.has_value());
+}