Add dot params transformer

lib/remote_record/transformers.rb

@@ -2,6 +2,7 @@
 
 require 'remote_record/transformers/base'
 require 'remote_record/transformers/snake_case'
+require 'remote_record/transformers/dot_params'
 
 module RemoteRecord
   # Classes responsible for transforming the hash of data returned by API calls.

lib/remote_record/transformers/dot_params.rb

@@ -0,0 +1,26 @@
+# frozen_string_literal: true
+
+module RemoteRecord
+  module Transformers
+    # Converts keys to snake case.
+    class DotParams < RemoteRecord::Transformers::Base
+      def transform
+        convert_hash_keys(@data).map { |k, v| "#{CGI.escape(k.to_s)}:#{CGI.escape(v.to_s)}" }.join(';')
+      end
+
+      private
+
+      def convert_hash_keys(data)
+        data.each_with_object({}) do |(k, v), h|
+          if v.is_a? Hash
+            convert_hash_keys(v).map do |h_k, h_v|
+              h["#{k}.#{h_k}".to_sym] = h_v
+            end
+          else
+            h[k] = v
+          end
+        end
+      end
+    end
+  end
+end

spec/transformers_spec.rb

@@ -32,4 +32,33 @@
       it { is_expected.to eq(1) }
     end
   end
+
+  describe described_class::DotParams do
+    let(:transformer) { described_class.new(data, direction) }
+    subject(:result) { transformer.transform }
+
+    context 'when the direction is not valid' do
+      let(:direction) { :left }
+      let(:data) { { userId: 1 } }
+
+      it 'is expected to raise an error' do
+        expect { transformer }.to raise_error ArgumentError
+      end
+    end
+
+    context 'when the direction is up' do
+      let(:direction) { :up }
+      let(:data) { { customer: { user_id: 1 }, state: :completed } }
+
+      it { is_expected.to eq('customer.user_id:1;state:completed') }
+    end
+
+    xcontext 'when the direction is down' do
+      let(:direction) { :down }
+      let(:expected_attribute_name) { :userId }
+      let(:data) { 'customer.user_id:1;state:completed' }
+
+      it { is_expected.to eq({ customer: { user_id: 1 }, state: :completed }) }
+    end
+  end
 end