flatten nested plugin config items (#27)

this builds upon PR #12 in that it extends the support to also cover
plugin configuration that is deeply nested:

    config = {
      a = {
        b = 1,
        c = 2
      }
    }

    # => {
    #      "config.a.b" => 1,
    #      "config.a.c" => 2
    #    }

lib/kong.rb

@@ -16,3 +16,4 @@
 require_relative 'kong/target'
 require_relative 'kong/upstream'
 require_relative 'kong/server'
+require_relative 'kong/util'

lib/kong/plugin.rb

@@ -1,3 +1,5 @@
+require_relative './util'
+
 module Kong
   class Plugin
     include Base
@@ -8,24 +10,22 @@ class Plugin
 
     # Create resource
     def create
-      if attributes['config']
-        attributes['config'].each do |key, value|
-          attributes["config.#{key}"] = value
-        end
-        attributes.delete('config')
-      end
+      flatten_config
       super
     end
 
     # update resource
     def update
+      flatten_config
+      super
+    end
+
+    private
+
+    def flatten_config
       if attributes['config']
-        attributes['config'].each do |key, value|
-          attributes["config.#{key}"] = value
-        end
-        attributes.delete('config')
+        attributes.merge!(Util.flatten(attributes.delete('config'), 'config'))
       end
-      super
     end
   end
 end

lib/kong/util.rb

@@ -0,0 +1,16 @@
+module Kong
+  module Util
+    def self.flatten(cursor, parent_key = nil, memo = {})
+      memo.tap do
+        case cursor
+        when Hash
+          cursor.keys.each do |key|
+            flatten(cursor[key], [parent_key, key].compact.join('.'), memo)
+          end
+        else
+          memo["#{parent_key}"] = cursor
+        end
+      end
+    end
+  end
+end

spec/kong/plugin_spec.rb

@@ -32,6 +32,14 @@
       subject = described_class.new({ api_id: ':api_id', config: { 'anonymous' => '12345' } })
       subject.create
     end
+
+    it 'transforms nested config keys to config.key format' do
+      headers = { 'Content-Type' => 'application/x-www-form-urlencoded' }
+      attributes = { 'api_id' => ':api_id', 'config.anonymous' => '12345', 'config.first.second' => '1' }
+      expect(Kong::Client.instance).to receive(:post).with('/apis/:api_id/plugins/', nil, attributes, headers).and_return(attributes)
+      subject = described_class.new({ api_id: ':api_id', config: { 'anonymous' => '12345', 'first' => { 'second' => '1' } } })
+      subject.create
+    end
   end
 
   describe '#update' do
@@ -42,5 +50,13 @@
       subject = described_class.new({ api_id: ':api_id', config: { 'anonymous' => '12345' } })
       subject.update
     end
+
+    it 'transforms nested config keys to config.key format' do
+      headers = { 'Content-Type' => 'application/x-www-form-urlencoded' }
+      attributes = { 'api_id' => ':api_id', 'config.anonymous' => '12345', 'config.first.second' => '1' }
+      expect(Kong::Client.instance).to receive(:patch).with('/apis/:api_id/plugins/', nil, attributes, headers).and_return(attributes)
+      subject = described_class.new({ api_id: ':api_id', config: { 'anonymous' => '12345', 'first' => { 'second' => '1' } } })
+      subject.update
+    end
   end
 end

spec/kong/util_spec.rb

@@ -0,0 +1,29 @@
+require_relative "../spec_helper"
+
+describe Kong::Util do
+  describe '.flatten' do
+    subject { described_class.method(:flatten) }
+
+    it 'works' do
+      expect(subject[{
+        a: {
+          b: 1,
+          c: {
+            d: 3
+          }
+        },
+        b: 2
+      }]).to include({
+        "a.b" => 1,
+        "a.c.d" => 3,
+        "b" => 2,
+      })
+    end
+
+    it 'accepts a scope' do
+      expect(subject[{ a: "1" }, 'config']).to eq({
+        "config.a" => "1"
+      })
+    end
+  end
+end