Function test_fuzzing

subprojects/llama.cpp/tests/test-jinja.cpp:1922–2290

}

static void test_fuzzing(testing & t) {
    const int num_iterations = JINJA_FUZZ_ITERATIONS;
    const unsigned int seed = 42; // fixed seed for reproducibility
    std::mt19937 rng(seed);

    // Distribution helpers
    std::uniform_int_distribution<int> choice_dist(0, 100);
    std::uniform_int_distribution<int> int_dist(-1000, 1000);
    std::uniform_int_distribution<size_t> idx_dist(0, 1000);

    // Template fragments for fuzzing
    const std::vector<std::string> var_names = {
        "x", "y", "z", "arr", "obj", "items", "foo", "bar", "undefined_var",
        "none", "true", "false", "None", "True", "False"
    };
    const std::vector<std::string> filters = {
        "length", "first", "last", "reverse", "sort", "unique", "join", "upper", "lower",
        "trim", "default", "tojson", "string", "int", "float", "abs", "list", "dictsort"
    };
    const std::vector<std::string> builtins = {
        "range", "len", "dict", "list", "join", "str", "int", "float", "namespace"
    };

    t.test("out of bound array access", [&](testing & t) {
        for (int i = 0; i < num_iterations; ++i) {
            int idx = int_dist(rng);
            std::string tmpl = "{{ arr[" + std::to_string(idx) + "] }}";
            json vars = {{"arr", json::array({1, 2, 3})}};
            t.assert_true("should not crash", fuzz_test_template(tmpl, vars));
        }
    });

    t.test("non-existing variables", [&](testing & t) {
        for (int i = 0; i < num_iterations; ++i) {
            std::string var = random_string(rng, 20);
            std::string tmpl = "{{ " + var + " }}";
            json vars = json::object(); // empty context
            t.assert_true("should not crash", fuzz_test_template(tmpl, vars));
        }
    });

    t.test("non-existing nested attributes", [&](testing & t) {
        for (int i = 0; i < num_iterations; ++i) {
            std::string var1 = var_names[choice_dist(rng) % var_names.size()];
            std::string var2 = random_string(rng, 10);
            std::string var3 = random_string(rng, 10);
            std::string tmpl = "{{ " + var1 + "." + var2 + "." + var3 + " }}";
            json vars = {{var1, {{"other", 123}}}};
            t.assert_true("should not crash", fuzz_test_template(tmpl, vars));
        }
    });

    t.test("invalid filter arguments", [&](testing & t) {
        for (int i = 0; i < num_iterations; ++i) {
            std::string filter = filters[choice_dist(rng) % filters.size()];
            int val = int_dist(rng);
            std::string tmpl = "{{ " + std::to_string(val) + " | " + filter + " }}";
            json vars = json::object();