如何用Js对decl_module中的方法进行测试

本文是对学习知识的总结和探索；如有不对的地方请指正；多谢；

学习了将近一个月的波卡开发，可是对一些测试的问题还是比较陌生；
如何使用Js对编写的decl_module中的方法进行测试，也成了一个不得不总结的问题；一句话会的人，不觉得难，不会的人找不到合适的方法；

1: 代码

#[derive(Encode, Decode, Default)]
pub struct Kitty(pub [u8; 16]);

decl_storage! {
    trait Store for Module as Kitties {
        /// Stores all the kitties, key is the kitty id / index
        pub Kitties get(kitty): map u32 => Kitty;
        /// Stores the total number of kitties. i.e. the next kitty index
        pub KittiesCount get(kitties_count): u32;
    }
}

decl_module! {
    pub struct Module for enum Call where origin: T::Origin {
        /// Create a new kitty
        pub fn create(origin) {
            let sender = ensure_signed(origin)?;
            let count = Self::kitties_count();
            if count == u32::max_value() {
                return Err("Kitties count overflow”);
            }
            let payload = (>::random_seed(), sender, >::extrinsic_index(), >::block_number());
            let dna = payload.using_encoded(blake2_128);
            let kitty = Kitty(dna);
            Kitties::insert(count, kitty);
            KittiesCount::put(count + 1);
        }
    }
}

2:启动环境

cargo run - - - - dev

2019-10-01 22:17:56 Prepared block for proposing at 7 [hash: 0x0b8e3245c6f8ae2972e9dbd64f45d985b0048fe6f49e7f312df1d40c9aae18ec; parent_hash: 0xedeb…fe45; extrinsics: [0x2d12…ab29]]
2019-10-01 22:17:56 Discarding proposal for slot 784969737; block production took too long
2019-10-01 22:17:56 Starting consensus session on top of parent 0xedebee52b36ac5c9e9e24e6a796d026ae53f9bed6d2eccf2d9295bc46905fe45
2019-10-01 22:17:57 Idle (0 peers), best: #6 (0xedeb…fe45), finalized #5 (0x3d2f…7d38), ⬇ 0 ⬆ 0
2019-10-01 22:17:58 Prepared block for proposing at 7 [hash: 0xea691d22666bde8c684b3d2d8392207a3bb9d7674f71d668206f631102b08aba; parent_hash: 0xedeb…fe45; extrinsics: [0x4e9d…7a6d]]
2019-10-01 22:17:58 Discarding proposal for slot 784969738; block production took too long
2019-10-01 22:17:58 Starting consensus session on top of parent 0xedebee52b36ac5c9e9e24e6a796d026ae53f9bed6d2eccf2d9295bc46905fe45
2019-10-01 22:18:00 Prepared block for proposing at 7 [hash: 0x96f22c8ad05a67b73b31772e025ee46d7005706d3782b2c92bfbbbfe9011b787; parent_hash: 0xedeb…fe45; extrinsics: [0x2e3d…5aad]]
2019-10-01 22:18:00 Discarding proposal for slot 784969739; block production took too long
2019-1