feat: raise error when an expected HAL relation cannot be found in a resource

Author: bethesque

lib/pact/hal/entity.rb

@@ -4,8 +4,12 @@
 
 module Pact
   module Hal
+    class RelationNotFoundError < ::Pact::Error; end
+
     class Entity
-      def initialize(data, http_client, response = nil)
+
+      def initialize(href, data, http_client, response = nil)
+        @href = href
         @data = data
         @links = (@data || {}).fetch("_links", {})
         @client = http_client
@@ -40,6 +44,10 @@ def _link(key)
         end
       end
 
+      def _link!(key)
+        _link(key) or raise RelationNotFoundError.new("Could not find relation '#{key}' in resource at #{@href}")
+      end
+
       def success?
         true
       end
@@ -69,7 +77,8 @@ def respond_to_missing?(method_name, include_private = false)
 
     class ErrorEntity < Entity
 
-      def initialize(data, http_client, response = nil)
+      def initialize(href, data, http_client, response = nil)
+        @href = href
         @data = data
         @links = {}
         @client = http_client

lib/pact/hal/link.rb

@@ -25,15 +25,15 @@ def run(payload = nil)
       end
 
       def get(payload = {}, headers = {})
-        wrap_response(@http_client.get(href, payload, headers))
+        wrap_response(href, @http_client.get(href, payload, headers))
       end
 
       def put(payload = nil, headers = {})
-        wrap_response(@http_client.put(href, payload ? JSON.dump(payload) : nil, headers))
+        wrap_response(href, @http_client.put(href, payload ? JSON.dump(payload) : nil, headers))
       end
 
       def post(payload = nil, headers = {})
-        wrap_response(@http_client.post(href, payload ? JSON.dump(payload) : nil, headers))
+        wrap_response(href, @http_client.post(href, payload ? JSON.dump(payload) : nil, headers))
       end
 
       def expand(params)
@@ -44,12 +44,12 @@ def expand(params)
 
       private
 
-      def wrap_response(http_response)
+      def wrap_response(href, http_response)
         require 'pact/hal/entity' # avoid circular reference
         if http_response.success?
-          Entity.new(http_response.body, @http_client, http_response)
+          Entity.new(href, http_response.body, @http_client, http_response)
         else
-          ErrorEntity.new(http_response.raw_body, @http_client, http_response)
+          ErrorEntity.new(href, http_response.raw_body, @http_client, http_response)
         end
       end
 

lib/pact/pact_broker/fetch_pacts.rb

@@ -64,9 +64,9 @@ def tagged_pacts_for_provider
 
       def link_for(tag)
         if !tag[:all]
-          index_entity._link(LATEST_PROVIDER_TAG_RELATION)
+          index_entity._link!(LATEST_PROVIDER_TAG_RELATION)
         else
-          index_entity._link(ALL_PROVIDER_TAG_RELATION)
+          index_entity._link!(ALL_PROVIDER_TAG_RELATION)
         end
       end
 
@@ -75,7 +75,7 @@ def index
       end
 
       def latest_pacts_for_provider
-        link = index_entity._link(LATEST_PROVIDER_RELATION)
+        link = index_entity._link!(LATEST_PROVIDER_RELATION)
         pact_urls(link.expand(provider: provider).get)
       end
 

lib/pact/provider/verification_results/publish.rb

@@ -32,7 +32,7 @@ def initialize pact_source, verification_result
           end
 
           @http_client = Pact::Hal::HttpClient.new(http_client_options)
-          @pact_entity = Pact::Hal::Entity.new(pact_source.pact_hash, http_client)
+          @pact_entity = Pact::Hal::Entity.new(pact_source.uri, pact_source.pact_hash, http_client)
         end
 
         def call

spec/lib/pact/hal/entity_spec.rb

@@ -32,7 +32,7 @@ module Hal
         }
       end
 
-      subject(:entity) { Entity.new(pact_hash, http_client) }
+      subject(:entity) { Entity.new("http://pact", pact_hash, http_client) }
 
       it "delegates to the properties in the data" do
         expect(subject.name).to eq "a name"
@@ -74,6 +74,21 @@ module Hal
         end
       end
 
+      describe "_link!" do
+        context 'when the key exists' do
+          it 'returns a Link' do
+            expect(subject._link!('pb:provider')).to be_a(Link)
+            expect(subject._link!('pb:provider').href).to eq 'http://provider'
+          end
+        end
+
+        context 'when the key does not exist' do
+          it 'raises an error' do
+            expect { subject._link!('foo') }.to raise_error RelationNotFoundError, "Could not find relation 'foo' in resource at http://pact"
+          end
+        end
+      end
+
       describe 'fetch' do
         context 'when the key exists' do
           it 'returns fetched value' do

spec/lib/pact/hal/link_spec.rb

@@ -48,7 +48,7 @@ module Hal
         end
 
         it "creates an Entity" do
-          expect(Pact::Hal::Entity).to receive(:new).with(response_body, http_client, response)
+          expect(Pact::Hal::Entity).to receive(:new).with("http://foo/{bar}", response_body, http_client, response)
           do_run
         end
 
@@ -64,7 +64,7 @@ module Hal
           let(:success) { false }
 
           it "creates an ErrorEntity" do
-            expect(Pact::Hal::ErrorEntity).to receive(:new).with(response_body.to_json, http_client, response)
+            expect(Pact::Hal::ErrorEntity).to receive(:new).with("http://foo/{bar}", response_body.to_json, http_client, response)
             do_run
           end
         end

spec/lib/pact/pact_broker/fetch_pacts_spec.rb

@@ -31,6 +31,16 @@ module PactBroker
           end
         end
 
+        context "when there is a HAL relation missing" do
+          before do
+            stub_request(:get, "http://broker.org/").to_return(status: 200, body: {"_links" => {} }.to_json, headers: {})
+          end
+
+          it "raises a Pact::Error" do
+            expect { subject }.to raise_error Pact::Error, /Could not find relation/
+          end
+        end
+
         context "for the latest tag" do
           it "logs a message" do
             expect(Pact.configuration.output_stream).to receive(:puts).with("INFO: Fetching pacts for Foo from http://broker.org for tags: latest master, latest prod")