feat: add compute_transaction_hash method

lib/ckb/wallet.rb

@@ -112,8 +112,7 @@ def generate_tx(target_address, capacity, data = "0x", key: nil, fee: 0)
         outputs_data: outputs.map(&:data),
         witnesses: i.witnesses
       )
-
-      tx_hash = api.compute_transaction_hash(tx)
+      tx_hash = compute_transaction_hash(tx)
 
       tx.sign(key, tx_hash)
     end
@@ -173,7 +172,7 @@ def deposit_to_dao(capacity, key: nil)
         witnesses: i.witnesses
       )
 
-      tx_hash = api.compute_transaction_hash(tx)
+      tx_hash = compute_transaction_hash(tx)
       send_transaction(tx.sign(key, tx_hash))
 
       Types::OutPoint.new(tx_hash: tx_hash, index: "0")
@@ -237,7 +236,7 @@ def generate_withdraw_from_dao_transaction(out_point, key: nil)
           Types::Witness.new(data: ["0x0000000000000000"])
         ]
       )
-      tx_hash = api.compute_transaction_hash(tx)
+      tx_hash = compute_transaction_hash(tx)
       tx.sign(key, tx_hash)
     end
 
@@ -271,6 +270,13 @@ def lock
 
     private
 
+    def compute_transaction_hash(tx)
+      raw_transaction_serializer = CKB::Serializers::RawTransactionSerializer.new(tx)
+      blake2b = CKB::Blake2b.new
+      blake2b << Utils.hex_to_bin("0x#{raw_transaction_serializer.serialize}")
+      blake2b.hexdigest
+    end
+
     # @param transaction [CKB::Transaction]
     def send_transaction(transaction)
       api.send_transaction(transaction)

spec/ckb/types/script_spec.rb

@@ -1,4 +1,3 @@
-require 'pry'
 RSpec.describe CKB::Types::Script do
   let(:script) do
     code_hash = CKB::Blake2b.hexdigest(