feat: Dynamically retrieve pacts for a given provider

Author: rashiagarwal

lib/pact/hal/entity.rb

@@ -0,0 +1,76 @@
+require 'uri'
+require 'delegate'
+require 'pact/hal/link'
+
+module Pact
+  module Hal
+    class Entity
+      def initialize(data, http_client, response = nil)
+        @data = data
+        @links = @data.fetch("_links", {})
+        @client = http_client
+        @response = response
+      end
+
+      def get(key, *args)
+        _link(key).get(*args)
+      end
+
+      def post(key, *args)
+        _link(key).post(*args)
+      end
+
+      def put(key, *args)
+        _link(key).put(*args)
+      end
+
+      def can?(key)
+        @links.key? key.to_s
+      end
+
+      def follow(key, http_method, *args)
+        Link.new(@links[key].merge(method: http_method), @client).run(*args)
+      end
+
+      def _link(key)
+        if @links[key]
+          Link.new(@links[key], @client)
+        else
+          nil
+        end
+      end
+
+      def success?
+        true
+      end
+
+      def response
+        @response
+      end
+
+      def fetch(key)
+        @links[key]
+      end
+
+      def method_missing(method_name, *args, &block)
+        if @data.key?(method_name.to_s)
+          @data[method_name.to_s]
+        elsif @links.key?(method_name)
+          Link.new(@links[method_name], @client).run(*args)
+        else
+          super
+        end
+      end
+
+      def respond_to_missing?(method_name, include_private = false)
+        @data.key?(method_name) || @links.key?(method_name)
+      end
+    end
+
+    class ErrorEntity < Entity
+      def success?
+        false
+      end
+    end
+  end
+end

lib/pact/hal/http_client.rb

@@ -0,0 +1,64 @@
+require 'pact/retry'
+
+module Pact
+  module Hal
+    class HttpClient
+      attr_accessor :username, :password
+
+      def initialize options
+        @username = options[:username]
+        @password = options[:password]
+      end
+
+      def get href, params = {}
+        uri = URI(href)
+        perform_request(create_request(uri, 'Get'), uri)
+      end
+
+      def put href, body = nil
+        uri = URI(href)
+        perform_request(create_request(uri, 'Put', body), uri)
+      end
+
+      def post href, body = nil
+        uri = URI(href)
+        perform_request(create_request(uri, 'Post', body), uri)
+      end
+
+      def create_request uri, http_method, body = nil
+        path = uri.path.size == 0 ? "/" : uri.path
+        request = Net::HTTP.const_get(http_method).new(path)
+        request['Content-Type'] = "application/json"
+        request['Accept'] = "application/hal+json"
+        request.body = body if body
+        request.basic_auth username, password if username
+        request
+      end
+
+      def perform_request request, uri
+        options = {:use_ssl => uri.scheme == 'https'}
+        response = Retry.until_true do
+          Net::HTTP.start(uri.host, uri.port, :ENV, options) do |http|
+            http.request request
+          end
+        end
+        Response.new(response)
+      end
+
+      class Response < SimpleDelegator
+        def body
+          bod = __getobj__().body
+          if bod && bod != ''
+            JSON.parse(bod)
+          else
+            nil
+          end
+        end
+
+        def success?
+          __getobj__().code.start_with?("2")
+        end
+      end
+    end
+  end
+end

lib/pact/hal/link.rb

@@ -0,0 +1,65 @@
+require 'uri'
+require 'delegate'
+
+module Pact
+  module Hal
+    class Link
+      attr_reader :request_method, :href
+
+      def initialize(attrs, http_client)
+        @attrs = attrs
+        @request_method = attrs.fetch(:method, :get).to_sym
+        @href = attrs.fetch('href')
+        @http_client = http_client
+      end
+
+      def run(payload = nil)
+        response = case request_method
+          when :get
+            get(payload)
+          when :put
+            put(payload)
+          when :post
+            post(payload)
+          end
+      end
+
+      def get(payload = {})
+        wrap_response(@http_client.get(href, payload))
+      end
+
+      def put(payload = nil)
+        wrap_response(@http_client.put(href, payload ? JSON.dump(payload) : nil))
+      end
+
+      def post(payload = nil)
+        wrap_response(@http_client.post(href, payload ? JSON.dump(payload) : nil))
+      end
+
+      def expand(params)
+        expanded_url = expand_url(params, href)
+        new_attrs = @attrs.merge('href' => expanded_url)
+        Link.new(new_attrs, @http_client)
+      end
+
+      private
+
+      def wrap_response(http_response)
+        require 'pact/hal/entity' # avoid circular reference
+        if http_response.success?
+          Entity.new(http_response.body, @http_client, http_response)
+        else
+          ErrorEntity.new(http_response.body, @http_client, http_response)
+        end
+      end
+
+      def expand_url(params, url)
+        new_url = url
+        params.each do | key, value |
+          new_url = new_url.gsub('{' + key.to_s + '}', value)
+        end
+        new_url
+      end
+    end
+  end
+end

lib/pact/pact_broker/fetch_pacts.rb

@@ -0,0 +1,53 @@
+require 'pact/hal/entity'
+require 'pact/hal/http_client'
+
+module Pact
+  module PactBroker
+    class FetchPacts
+      attr_reader :provider, :tags, :broker_base_url, :basic_auth_options, :http_client, :pact_entity
+
+      LATEST_PROVIDER_TAG_RELATION = 'pb:latest-provider-pacts-with-tag'.freeze
+      LATEST_PROVIDER_RELATION = 'pb:latest-provider-pacts'.freeze
+      PACTS = 'pacts'.freeze
+      HREF = 'href'.freeze
+
+      def initialize(provider, tags, broker_base_url, basic_auth_options)
+        @provider = provider
+        @tags = tags
+
+        @http_client = Pact::Hal::HttpClient.new(basic_auth_options)
+        @response = @http_client.get(broker_base_url)
+        @pact_entity = Pact::Hal::Entity.new(@response.body, http_client)
+      end
+
+      def self.call(provider, tags = nil, broker_base_url, basic_auth_options)
+        new(provider, tags, broker_base_url, basic_auth_options).call
+      end
+
+      def call
+        pact_urls = []
+        if tags
+          link = pact_entity._link(LATEST_PROVIDER_TAG_RELATION)
+          tags.each do |tag|
+            link_by_tag = link.expand(provider: provider, tag: tag).get
+            get_pact_urls(link_by_tag, pact_urls)
+          end
+        else
+          link = pact_entity._link(LATEST_PROVIDER_RELATION)
+          link_by_provider = link.expand(provider: provider).get
+          get_pact_urls(link_by_provider, pact_urls)
+        end
+        pact_urls
+      end
+
+      private
+
+      def get_pact_urls(link_by_provider, pact_urls)
+        pacts = link_by_provider.fetch(PACTS)
+        pacts.each do |pact|
+          pact_urls.push(pact[HREF])
+        end
+      end
+    end
+  end
+end