feat(webhooks): show better error message when the pb:webhooks relati…

…on doesn't exist when trying to create a webhook

lib/pact_broker/client/base_client.rb

@@ -125,7 +125,7 @@ def url_for_relation relation_name, params
             end
             url
           else
-            raise PactBroker::Client::RelationNotFound.new("Could not find relation #{relation_name} in index resource. Try upgrading your Pact Broker as the feature you require may not exist in your version.")
+            raise PactBroker::Client::RelationNotFound.new("Could not find relation #{relation_name} in index resource. Try upgrading your Pact Broker as the feature you require may not exist in your version. If you are using Pactflow, you may not have the permissions required for this action.")
           end
         end
       end

lib/pact_broker/client/hal/entity.rb

@@ -91,11 +91,11 @@ def _links(key)
         end
 
         def _link!(key)
-          _link(key) or raise RelationNotFoundError.new("Could not find relation '#{key}' in resource at #{@href}")
+          _link(key) or raise RelationNotFoundError.new(relation_not_found_error_message(key, @href))
         end
 
         def _links!(key)
-          _links(key) or raise RelationNotFoundError.new("Could not find relation '#{key}' in resource at #{@href}")
+          _links(key) or raise RelationNotFoundError.new(relation_not_found_error_message(key, @href))
         end
 
         def embedded_entity
@@ -161,6 +161,10 @@ def assert_success!(_ignored = nil)
         def self_href(entity_hash)
           entity_hash["_links"] && entity_hash["_links"]["self"] && entity_hash["_links"]["self"]["href"]
         end
+
+        def relation_not_found_error_message(key, href)
+          "Could not find relation '#{key}' in resource at #{href}. The most likely reason for this is that you are on an old version of the Pact Broker and you need to upgrade, or you are using Pactflow and you don't have the permissions required for this action."
+        end
       end
 
       class ErrorEntity < Entity

lib/pact_broker/client/webhooks/create.rb

@@ -50,7 +50,7 @@ def create_webhook_with_optional_consumer_and_provider
               return error_result(CREATING_WEBHOOK_WITH_UUID_NOT_SUPPORTED)
             end
           else
-            webhook_entity = index_entity._link("pb:webhooks").post(request_body_with_optional_consumer_and_provider)
+            webhook_entity = index_entity._link!("pb:webhooks").post(request_body_with_optional_consumer_and_provider)
           end
 
           if webhook_entity.response.status == 405

spec/lib/pact_broker/client/hal/entity_spec.rb

@@ -112,7 +112,7 @@ module Hal
 
         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"
+            expect { subject._link!('foo') }.to raise_error RelationNotFoundError, /Could not find relation 'foo' in resource at http:\/\/pact/
           end
         end
       end