add comments to api and basic class

app/models/cita_sync/api.rb

@@ -32,6 +32,13 @@ class << self
         end
       end
 
+      # post params to cita and get response, decode response body and get hash
+      #
+      # @param method [String, Symbol] rpc method name
+      # @param params [Hash] rpc params
+      # @param jsonrpc [String] jsonrpc version, default with "2.0"
+      # @param id [Integer] id number
+      # @return [Hash, String, Array] json decode to hash
       def call_rpc(method, params: params, jsonrpc: jsonrpc, id: id)
         resp = CitaSync::Basic.post(method, params: params, jsonrpc: jsonrpc, id: id)
         Oj.load(resp.body)

app/models/cita_sync/basic.rb

@@ -2,18 +2,37 @@ module CitaSync
   module Basic
     class << self
 
+      # convert decimal number to hex string with "0x" prefix
+      #
+      # @param number [Integer]
+      # @return [String]
       def number_to_hex_str(number)
         "0x" + number.to_s(16)
       end
 
+      # convert hex string to decimal number
+      #
+      # @param str [String] hex string
+      # @return [Integer] decimal number
       def hex_str_to_number(str)
         str.to_i(16)
       end
 
+      # post params to cita and get response
+      # @param method [String, Symbol]
+      # @param jsonrpc [String] jsonrpc version, default with "2.0" and only can be "2.0"
+      # @param id [Integer] rpc id, default with 83
+      # @return [Faraday::Response] http response
       def post(method, jsonrpc: "2.0", params: [], id: 83)
         conn.post("/", params(method, jsonrpc: jsonrpc, params: params, id: id))
       end
 
+      # wrapper params for cita with default params and to json
+      #
+      # @param method [String, Symbol] rpc method name
+      # @param jsonrpc [String] jsonrpc version, default with "2.0" and only can be "2.0"
+      # @param id [Integer] rpc id, default with 83
+      # @return [String] params in json
       def params(method, jsonrpc: "2.0", params: [], id: 83)
         {
           jsonrpc: jsonrpc,
@@ -23,6 +42,9 @@ def params(method, jsonrpc: "2.0", params: [], id: 83)
         }.to_json
       end
 
+      # wrapper faraday object with cita_url and Content-Type
+      #
+      # @return [Faraday]
       def conn
         Faraday.new(url: cita_url) do |faraday|
           faraday.headers['Content-Type'] = 'application/json'
@@ -32,17 +54,27 @@ def conn
         end
       end
 
+      # get CITA_URL in ENV
+      #
+      # @return [String] cita chain url (with port if need) like http://www.example.com
       def cita_url
         ENV.fetch("CITA_URL")
       end
 
       # make params key chainId => chain_id
       # not deep transfer keys, only transfer first level keys
+      #
+      # @param params [Hash]
+      # @return [Hash]
       def transfer_params(params)
         params.map { |k, v| { k.to_s.underscore => v } }.reduce(:merge)
       end
 
-      # select params
+      # select params that key in keys
+      #
+      # @param params [Hash]
+      # @param keys [Array<String, Symbol>]
+      # @return [Hash] selected params
       def select_params(params, keys = [])
         underscore_params = transfer_params(params)
         underscore_params.select { |k, _v| keys.include?(k) }