Add Bitcoin::Descriptor::KeyExpression#extracted_key

lib/bitcoin/descriptor/combo.rb

@@ -9,7 +9,7 @@ def type
 
       def to_scripts
         candidates = [Pk.new(key), Pkh.new(key)]
-        pubkey = extract_pubkey(key)
+        pubkey = extracted_key
         if pubkey.compressed?
           candidates << Wpkh.new(pubkey.pubkey)
           candidates << Sh.new(candidates.last)

lib/bitcoin/descriptor/key_expression.rb

@@ -18,6 +18,13 @@ def args
       def top_level?
         false
       end
+
+      # Get extracted key.
+      # @return [Bitcoin::Key] Extracted key.
+      def extracted_key
+        extract_pubkey(key)
+      end
+
     end
   end
 end

lib/bitcoin/descriptor/pk.rb

@@ -18,7 +18,7 @@ def type
       # Convert to bitcoin script.
       # @return [Bitcoin::Script]
       def to_script
-        k = extract_pubkey(key)
+        k = extracted_key
         target_key = xonly ? k.xonly_pubkey : k.pubkey
         Bitcoin::Script.new << target_key << OP_CHECKSIG
       end

lib/bitcoin/descriptor/pkh.rb

@@ -8,7 +8,7 @@ def type
       end
 
       def to_script
-        Script.to_p2pkh(extract_pubkey(key).hash160)
+        Script.to_p2pkh(extracted_key.hash160)
       end
     end
   end

lib/bitcoin/descriptor/raw_tr.rb

@@ -13,8 +13,7 @@ def top_level?
       end
 
       def to_script
-        k = extract_pubkey(key)
-        Bitcoin::Script.new << OP_1 << k.xonly_pubkey
+        Bitcoin::Script.new << OP_1 << extract_pubkey(key).xonly_pubkey
       end
     end
   end

lib/bitcoin/descriptor/wpkh.rb

@@ -12,7 +12,7 @@ def type
       end
 
       def to_script
-        Script.to_p2wpkh(extract_pubkey(key).hash160)
+        Script.to_p2wpkh(extracted_key.hash160)
       end
     end
   end