An exception occures when an invalid JWT is passed to the TryDecode method

[xin9le]

Summary

The decoding process in JWT is generally performed on the token sent from the client side. For this token, invalid values such as missing strings need to be considered. Generally, the TryXxx method doesn't throw any exceptions and returns the boolean value of success/failure. However, TryDecode method throws an exception when an invalid value is passed.

Reproduction Code

using LitJWT;
using LitJWT.Algorithms;
using Utf8Json;

void Main()
{
    var algo = new HS256Algorithm(HS256Algorithm.GenerateRandomRecommendedKey());
    var encoder = new JwtEncoder(algo);
    var decoder = new JwtDecoder(encoder.SignAlgorithm);

    var input = new Person{ Name = "xin9le", Age = 36 };
    var expiry = TimeSpan.FromSeconds(10);
    var jwt = encoder.Encode(input, expiry, (x, w) => w.Write(JsonSerializer.SerializeUnsafe(x)));
    jwt.Dump("JWT");
    
    var invalidJwt = jwt.AsSpan(0, 10);
    var result = decoder.TryDecode(invalidJwt, x => JsonSerializer.Deserialize<Person>(x.ToArray()), out var output);
    
    result.Dump("Result");
    output.Dump("Output");
}

public class Person
{
    public string Name { get; init; }
    public int Age { get; init; }
}

Expected behavior

• No exception occurs
• Should return enum value like DecodeResult.InvalidFormat