Use head ref for url generation in offense formatter

Author: martinemde

lib/danger-packwerk/danger_package_todo_yml_changes.rb

@@ -42,7 +42,7 @@ def check(
     )
       offenses_formatter ||= Update::DefaultFormatter.new
       repo_link = github.pr_json[:base][:repo][:html_url]
-      repo_url_builder = ->(constant_path) { "#{repo_link}/blob/main/#{constant_path}" }
+      repo_url_builder = ->(constant_path) { "#{repo_link}/blob/#{github.pr_json[:head][:ref]}/#{constant_path}" }
       org_name = github.pr_json[:base][:repo][:owner][:login]
 
       git_filesystem = Private::GitFilesystem.new(git: git, root: root_path || '')

lib/danger-packwerk/danger_packwerk.rb

@@ -64,7 +64,7 @@ def check(
     )
       offenses_formatter ||= Check::DefaultFormatter.new
       repo_link = github.pr_json[:base][:repo][:html_url]
-      repo_url_builder = ->(constant_path) { "#{repo_link}/blob/main/#{constant_path}" }
+      repo_url_builder = ->(constant_path) { "#{repo_link}/blob/#{github.pr_json[:head][:ref]}/#{constant_path}" }
       org_name = github.pr_json[:base][:repo][:owner][:login]
 
       # This is important because by default, Danger will leave a concantenated list of all its messages if it can't find a commentable place in the

spec/danger_packwerk/danger_packwerk_spec.rb

@@ -859,7 +859,7 @@ def format_offenses(offenses, repo_link, org_name, repo_url_builder: nil)
             expected = <<~EXPECTED
               **Packwerk Violation**
               - Type: Privacy :lock:
-              - Constant: [<ins>`PrivateConstant`</ins>](https://github.com/MyOrg/my_repo/blob/main/packs/gusto_slack/app/services/private_constant.rb)
+              - Constant: [<ins>`PrivateConstant`</ins>](https://github.com/MyOrg/my_repo/blob/my_branch/packs/gusto_slack/app/services/private_constant.rb)
               - Owning pack: packs/gusto_slack
                 - Owned by [<ins>@MyOrg/product-infrastructure</ins>](https://github.com/orgs/MyOrg/teams/product-infrastructure/members) (Slack: [<ins>#prod-infra</ins>](https://slack.com/app_redirect?channel=prod-infra))
 
@@ -900,7 +900,7 @@ def format_offenses(offenses, repo_link, org_name, repo_url_builder: nil)
               expected = <<~EXPECTED
                 **Packwerk Violation**
                 - Type: Privacy :lock:
-                - Constant: [<ins>`PrivateConstant`</ins>](https://github.com/MyOrg/my_repo/blob/main/packs/gusto_slack/app/services/private_constant.rb)
+                - Constant: [<ins>`PrivateConstant`</ins>](https://github.com/MyOrg/my_repo/blob/my_branch/packs/gusto_slack/app/services/private_constant.rb)
                 - Owning pack: packs/gusto_slack
                   - This pack is unowned.
 
@@ -943,7 +943,7 @@ def format_offenses(offenses, repo_link, org_name, repo_url_builder: nil)
             expected = <<~EXPECTED
               **Packwerk Violation**
               - Type: Dependency :knot:
-              - Constant: [<ins>`PrivateConstant`</ins>](https://github.com/MyOrg/my_repo/blob/main/packs/gusto_slack/app/services/private_constant.rb)
+              - Constant: [<ins>`PrivateConstant`</ins>](https://github.com/MyOrg/my_repo/blob/my_branch/packs/gusto_slack/app/services/private_constant.rb)
               - Owning pack: packs/gusto_slack
                 - Owned by [<ins>@MyOrg/product-infrastructure</ins>](https://github.com/orgs/MyOrg/teams/product-infrastructure/members) (Slack: [<ins>#prod-infra</ins>](https://slack.com/app_redirect?channel=prod-infra))
 
@@ -984,7 +984,7 @@ def format_offenses(offenses, repo_link, org_name, repo_url_builder: nil)
             expected = <<~EXPECTED
               **Packwerk Violation**
               - Type: Privacy :lock: + Dependency :knot:
-              - Constant: [<ins>`PrivateConstant`</ins>](https://github.com/MyOrg/my_repo/blob/main/packs/gusto_slack/app/services/private_constant.rb)
+              - Constant: [<ins>`PrivateConstant`</ins>](https://github.com/MyOrg/my_repo/blob/my_branch/packs/gusto_slack/app/services/private_constant.rb)
               - Owning pack: packs/gusto_slack
                 - Owned by [<ins>@MyOrg/product-infrastructure</ins>](https://github.com/orgs/MyOrg/teams/product-infrastructure/members) (Slack: [<ins>#prod-infra</ins>](https://slack.com/app_redirect?channel=prod-infra))
 
@@ -1057,7 +1057,7 @@ def format_offenses(offenses, repo_link, org_name, repo_url_builder: nil)
               expected = <<~EXPECTED
                 **Packwerk Violation**
                 - Type: Privacy :lock:
-                - Constant: [<ins>`PrivateConstant`</ins>](https://github.com/MyOrg/my_repo/blob/main/packs/gusto_slack/app/services/private_constant.rb)
+                - Constant: [<ins>`PrivateConstant`</ins>](https://github.com/MyOrg/my_repo/blob/my_branch/packs/gusto_slack/app/services/private_constant.rb)
                 - Owning pack: packs/gusto_slack
                   - Owned by [<ins>@MyOrg/product-infrastructure</ins>](https://github.com/orgs/MyOrg/teams/product-infrastructure/members) (Slack: [<ins>#prod-infra</ins>](https://slack.com/app_redirect?channel=prod-infra))
 

spec/support/danger_plugin.rb

@@ -6,6 +6,7 @@
   let(:renamed_files) { [] }
   let(:pr_json) do
     {
+      head: { ref: 'my_branch' },
       base: {
         repo: {
           html_url: 'https://github.com/MyOrg/my_repo',