Jira Issue: Fix comments' datetime

When we query the Jira API, we use renderedFields option to get some
values (description and comments) as HTML. That way we can render that
information in GitLab.  That way, we can get the Jira Issue data from
the Jira API response in two formats: fields and renderedFields.

"fields": {
  ...
  "comment": {
    "comments": [
      ...
          "displayName": "Arturo Herrero",
          "active": true,
          "timeZone": "Europe/London"
        },
        "created": "2021-03-10T10:05:51.199+0000",
        "updated": "2021-03-10T10:05:51.199+0000"
      },
  ...
}
"renderedFields": {
  ...
  "comment": {
    "comments": [
      ...
          "displayName": "Arturo Herrero",
          "active": true,
          "timeZone": "Europe/London"
        },
        "created": "2 days ago 10:05 AM",
        "updated": "2 days ago 10:05 AM"
      },
  ...
}

Using renderedFields we can get some of the following formats:

- "Just now"
- "2 days ago 10:05 AM"
- "24/Feb/21 7:19 AM"

Instead of the datetime with timezone from fields:

- "2021-03-10T10:05:51.199+0000"

We have to get the datetimes' fields from the fields key as it's more
reliable and easy to consume in our end.

ee/app/serializers/integrations/jira/issue_detail_entity.rb

@@ -4,8 +4,7 @@ module Integrations
   module Jira
     class IssueDetailEntity < ::Integrations::Jira::IssueEntity
       expose :description_html do |jira_issue|
-        Banzai::Pipeline::JiraGfmPipeline
-          .call(jira_issue.renderedFields['description'], project: project)[:output].to_html
+        jira_gfm_pipeline(jira_issue.renderedFields['description'])
       end
 
       expose :state do |jira_issue|
@@ -17,16 +16,22 @@ module Integrations
       end
 
       expose :comments do |jira_issue|
-        jira_issue.renderedFields['comment']['comments'].map do |comment|
+        jira_issue.fields['comment']['comments'].map.with_index do |comment, index|
           {
             id: comment['id'],
-            body_html: Banzai::Pipeline::JiraGfmPipeline.call(comment['body'], project: project)[:output].to_html,
+            body_html: jira_gfm_pipeline(jira_issue.renderedFields['comment']['comments'][index]['body']),
             created_at: comment['created'].to_datetime.utc,
             updated_at: comment['updated'].to_datetime.utc,
             author: jira_user(comment['author'])
           }
         end
       end
+
+      private
+
+      def jira_gfm_pipeline(html)
+        Banzai::Pipeline::JiraGfmPipeline.call(html, project: project)[:output].to_html
+      end
     end
   end
 end

ee/spec/serializers/integrations/jira/issue_detail_entity_spec.rb

@@ -40,11 +40,7 @@ RSpec.describe Integrations::Jira::IssueDetailEntity do
         'comment' => {
           'comments' => [
             {
-              'id' => '10022',
-              'author' => comment_author,
-              'body' => '<p>Comment</p>',
-              'created' => '2020-06-25T15:50:00.000+0000',
-              'updated' => '2020-06-25T15:51:00.000+0000'
+              'body' => '<p>Comment</p>'
             }
           ]
         }
@@ -56,7 +52,18 @@ RSpec.describe Integrations::Jira::IssueDetailEntity do
       labels: ['backend'],
       fields: {
         'reporter' => reporter,
-        'assignee' => assignee
+        'assignee' => assignee,
+        'comment' => {
+          'comments' => [
+            {
+              'id' => '10022',
+              'author' => comment_author,
+              'body' => '<p>Comment</p>',
+              'created' => '2020-06-25T15:50:00.000+0000',
+              'updated' => '2020-06-25T15:51:00.000+0000'
+            }
+          ]
+        }
       },
       project: double(key: 'GL'),
       key: 'GL-5',