Add helper method to parse URI parameter from an adapter URI

lib/rackstash/adapter/base_adapter.rb

@@ -5,6 +5,9 @@
 # This software may be modified and distributed under the terms
 # of the MIT license. See the LICENSE.txt file for details.
 
+require 'cgi'
+require 'uri'
+
 require 'rackstash/adapter'
 require 'rackstash/encoder/json'
 
@@ -34,6 +37,30 @@ module Rackstash
         Rackstash::Adapter.register(self, *matchers)
       end
 
+      class << self
+        private
+
+        def parse_uri_options(uri)
+          options = {}
+          (uri.query || EMPTY_STRING).split(/[&;] */n).each do |option|
+            next if option.empty?
+            k, v = option.split('='.freeze, 2).map! { |s| CGI.unescape(s) }
+            k = k.to_sym
+
+            if cur = options[k]
+              if cur.class == Array
+                options[k] << v
+              else
+                options[k] = [cur, v]
+              end
+            else
+              options[k] = v
+            end
+          end
+          options
+        end
+      end
+
       # Create a new adapter instance.
       #
       # Usually, this method is overwritten by child classes to accept a

spec/rackstash/adapter/base_adapter_spec.rb

@@ -12,6 +12,28 @@ require 'rackstash/adapter/base_adapter'
 describe Rackstash::Adapter::BaseAdapter do
   let(:adapter) { described_class.new }
 
+  describe '.parse_uri_options' do
+    it 'returns a Hash of query options' do
+      expect(described_class.send :parse_uri_options, URI('/?foo=bar&baz=bums'))
+        .to eql foo: 'bar', baz: 'bums'
+    end
+
+    it 'does not parse special values' do
+      expect(described_class.send :parse_uri_options, URI('/?i=42&f=3.14&b=false&a[]=nil'))
+        .to eql i: '42', f: '3.14', b: 'false', :'a[]' => 'nil'
+    end
+
+    it 'accepts common separators' do
+      expect(described_class.send :parse_uri_options, URI('/?a=b;c=d&e=f;g=h'))
+        .to eql a: 'b', c: 'd', e: 'f', g: 'h'
+    end
+
+    it 'parses multiple values of the same key into an array' do
+      expect(described_class.send :parse_uri_options, URI('/?key=foo&key=bar&key=baz'))
+        .to eql key: ['foo', 'bar', 'baz']
+    end
+  end
+
   describe '#initialize' do
     it 'accepts any arguments' do
       described_class.new
@@ -20,7 +42,7 @@ describe Rackstash::Adapter::BaseAdapter do
     end
   end
 
-  describe '.default_encoder' do
+  describe '#default_encoder' do
     it 'returns an encoder' do
       expect(adapter.default_encoder).to respond_to(:encode)
     end