How to change return value

[zhangguanzhang]

method YYY:

public static byte[] YYY(ref string contentFile)

hook return value will Error: expected a pointer

import "frida-il2cpp-bridge";

Il2Cpp.perform(() => {

    console.log("Unity version: " + Il2Cpp.unityVersion);
    const XXX = Il2Cpp.domain.assembly('Assembly-CSharp').image.class('XXX');
    const YYY = XXX.method("YYY");

    YYY.implementation = function (item): Uint8Array {
        var result = this.method<Uint8Array>("YYY").invoke(item);
        var file = new File("text.txt", "r");
        return file.readBytes(); // <------ Error: expected a pointer
    };
});

---

this will hung:

import "frida-il2cpp-bridge";

Il2Cpp.perform(() => {

    console.log("Unity version: " + Il2Cpp.unityVersion);
    const XXX = Il2Cpp.domain.assembly('Assembly-CSharp').image.class('XXX');
    const YYY = XXX.method("YYY");

   var byteArray;

    YYY.implementation = function (item): Uint8Array {
        var result = this.method<Uint8Array>("YYY").invoke(item);
        var file = new File("text.txt", "r");
         byteArray = file.readBytes()
            console.log(hexdump(byteArray, {
                offset: 0,
                length: byteArray.byteLength,
                header: true,
                ansi: true,
            }));
            return byteArray.unwrap();
    };
});

---

use Il2Cpp.array will：

Error: expected an unsigned integer
    at array (il2cpp/structs/array.ts:92)
    at <anonymous> (index.ts:xx) <---- return bytePointer line
    at call (native)
    at <anonymous> (il2cpp/structs/method.ts:354)

import "frida-il2cpp-bridge";

Il2Cpp.perform(() => {

    console.log("Unity version: " + Il2Cpp.unityVersion);
    const XXX = Il2Cpp.domain.assembly('Assembly-CSharp').image.class('XXX');
    const YYY = XXX.method("YYY");

   const SystemByte = Il2Cpp.corlib.class("System.Byte");

   var byteArray;

    YYY.implementation = function (item): Uint8Array {
        var result = this.method<Uint8Array>("YYY").invoke(item);
        var file = new File("text.txt", "r");
         byteArray = file.readBytes()
         var bytePointer = Il2Cpp.array(SystemByte, byteArray);
            return bytePointer;
    };
});

[zhangguanzhang]

@vfsfitvnm PTAL 😘

[zhangguanzhang]

var resultPoint = new NativePointer(result.handle)
            var newResultPoint = resultPoint.add(32)