v3(services): fix documentation_url field

Fix the service offering documentation_url field when included in a
service instance request.

[#173447953](https://www.pivotaltracker.com/story/show/173447953)

Co-authored-by: George Blue <gblue@pivotal.io>

Author: Brian Butz

app/decorators/field_service_instance_offering_decorator.rb

@@ -25,7 +25,7 @@ def decorate(hash, service_instances)
         offering_view[:name] = offering.name if @fields.include?('name')
         offering_view[:guid] = offering.guid if @fields.include?('guid')
         offering_view[:description] = offering.description if @fields.include?('description')
-        offering_view[:documentation_url] = offering.documentation_url if @fields.include?('documentation_url')
+        offering_view[:documentation_url] = extract_documentation_url(offering.extra) if @fields.include?('documentation_url')
         if @fields.include?('relationships.service_broker')
           offering_view[:relationships] = {
             service_broker: {
@@ -41,5 +41,14 @@ def decorate(hash, service_instances)
 
       hash
     end
+
+    private
+
+    def extract_documentation_url(extra)
+      metadata = JSON.parse(extra)
+      metadata['documentation_url']
+    rescue JSON::ParserError
+      nil
+    end
   end
 end

spec/request/service_instances_spec.rb

@@ -144,7 +144,7 @@
               name: instance.service_plan.service.name,
               guid: instance.service_plan.service.guid,
               description: instance.service_plan.service.description,
-              documentation_url: instance.service_plan.service.documentation_url,
+              documentation_url: 'https://some.url.for.docs/',
             }
           ],
           service_brokers: [
@@ -407,7 +407,7 @@ def check_filtered_instances(*instances)
               name: msi_1.service_plan.service.name,
               guid: msi_1.service_plan.service.guid,
               description: msi_1.service_plan.service.description,
-              documentation_url: msi_1.service_plan.service.documentation_url,
+              documentation_url: 'https://some.url.for.docs/',
               relationships: {
                 service_broker: {
                   data: {
@@ -420,7 +420,7 @@ def check_filtered_instances(*instances)
               name: msi_2.service_plan.service.name,
               guid: msi_2.service_plan.service.guid,
               description: msi_2.service_plan.service.description,
-              documentation_url: msi_2.service_plan.service.documentation_url,
+              documentation_url: 'https://some.url.for.docs/',
               relationships: {
                 service_broker: {
                   data: {
@@ -433,7 +433,7 @@ def check_filtered_instances(*instances)
               name: ssi.service_plan.service.name,
               guid: ssi.service_plan.service.guid,
               description: ssi.service_plan.service.description,
-              documentation_url: ssi.service_plan.service.documentation_url,
+              documentation_url: 'https://some.url.for.docs/',
               relationships: {
                 service_broker: {
                   data: {

spec/unit/decorators/field_service_instance_offering_decorator_spec.rb

@@ -4,8 +4,8 @@
 module VCAP::CloudController
   RSpec.describe FieldServiceInstanceOfferingDecorator do
     describe '.decorate' do
-      let(:offering1) { Service.make }
-      let(:offering2) { Service.make }
+      let(:offering1) { Service.make(extra: '{"documentation_url": "https://offering1.com"}') }
+      let(:offering2) { Service.make(extra: '{"documentation_url": "https://offering2.com"}') }
 
       let(:plan1) { ServicePlan.make(service: offering1) }
       let(:plan2) { ServicePlan.make(service: offering2) }
@@ -91,10 +91,10 @@ module VCAP::CloudController
             monkeys: %w(zach greg),
             service_offerings: [
               {
-                documentation_url: offering1.documentation_url,
+                documentation_url: 'https://offering1.com',
               },
               {
-                documentation_url: offering2.documentation_url,
+                documentation_url: 'https://offering2.com',
               }
             ]
           }