diff --git a/app/workers/admin_email_worker.rb b/app/workers/admin_email_worker.rb
index 044e470141ecbb931c2962b15fb858074908ffeb..06324575ffcb3b27f003d0824320c61aff2bd7c7 100644
--- a/app/workers/admin_email_worker.rb
+++ b/app/workers/admin_email_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AdminEmailWorker
   include ApplicationWorker
   include CronjobQueue
diff --git a/app/workers/archive_trace_worker.rb b/app/workers/archive_trace_worker.rb
index dea7425ad88d4d331d57f02e17e233d13f04fd03..9169f21af2a983a0712d11942468d4e9b0a30fc3 100644
--- a/app/workers/archive_trace_worker.rb
+++ b/app/workers/archive_trace_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ArchiveTraceWorker
   include ApplicationWorker
   include PipelineBackgroundQueue
diff --git a/app/workers/authorized_projects_worker.rb b/app/workers/authorized_projects_worker.rb
index 8fe3619f6ee2de70df8c9183fd3a201bb044c40e..dd62bb0f33d9831c02a99340232846c831d87a33 100644
--- a/app/workers/authorized_projects_worker.rb
+++ b/app/workers/authorized_projects_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class AuthorizedProjectsWorker
   include ApplicationWorker
   prepend WaitableWorker
diff --git a/app/workers/background_migration_worker.rb b/app/workers/background_migration_worker.rb
index 376703f631924349ef0bbc1d14f5b1a960dd2753..eaec7d48f35183849fafc107d57ba4c34418ae79 100644
--- a/app/workers/background_migration_worker.rb
+++ b/app/workers/background_migration_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class BackgroundMigrationWorker
   include ApplicationWorker
 
diff --git a/app/workers/build_coverage_worker.rb b/app/workers/build_coverage_worker.rb
index 62b212c79be56dc71da3a3946e5a48cf7d226e1e..53d77dc45249f37d1125e4f44c4d8aba075937f8 100644
--- a/app/workers/build_coverage_worker.rb
+++ b/app/workers/build_coverage_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class BuildCoverageWorker
   include ApplicationWorker
   include PipelineQueue
diff --git a/app/workers/build_finished_worker.rb b/app/workers/build_finished_worker.rb
index 46f1ac099156468446c05c8a89a471dfd53065c6..9dc2c7f36018d2d115429bd5d1d11af0eb548ecb 100644
--- a/app/workers/build_finished_worker.rb
+++ b/app/workers/build_finished_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class BuildFinishedWorker
   include ApplicationWorker
   include PipelineQueue
diff --git a/app/workers/build_hooks_worker.rb b/app/workers/build_hooks_worker.rb
index cbfca8c342c768802def31dade367fa96e7e8d33..f1f71dc589cc4ab592c29dd19c07919f9ec2b85f 100644
--- a/app/workers/build_hooks_worker.rb
+++ b/app/workers/build_hooks_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class BuildHooksWorker
   include ApplicationWorker
   include PipelineQueue
diff --git a/app/workers/build_queue_worker.rb b/app/workers/build_queue_worker.rb
index e4f4e6c1d9e2b513287bb75dd919a8d8c8a194e6..1b3f1fd3c2ac4998072d0d93b776dc4dc31b90c4 100644
--- a/app/workers/build_queue_worker.rb
+++ b/app/workers/build_queue_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class BuildQueueWorker
   include ApplicationWorker
   include PipelineQueue
diff --git a/app/workers/build_success_worker.rb b/app/workers/build_success_worker.rb
index 4b9097bc5e4ed9461a17abcb7a10d2ad674879b1..e1c1cc24a94a07e54ba1a52ac128169405b0c328 100644
--- a/app/workers/build_success_worker.rb
+++ b/app/workers/build_success_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class BuildSuccessWorker
   include ApplicationWorker
   include PipelineQueue
diff --git a/app/workers/build_trace_sections_worker.rb b/app/workers/build_trace_sections_worker.rb
index c0f5c144e10f6881573cd5cb8a63a4fa0a5ef7db..f4114b3353cdb518660e4c52ab41fcd7cb6f2dea 100644
--- a/app/workers/build_trace_sections_worker.rb
+++ b/app/workers/build_trace_sections_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class BuildTraceSectionsWorker
   include ApplicationWorker
   include PipelineQueue
diff --git a/app/workers/cluster_install_app_worker.rb b/app/workers/cluster_install_app_worker.rb
index f771cb4939f9fd500a1432f572c9003e68541eb1..32e2ea7996c4d6c7b3c2e32ffa698fa6df744783 100644
--- a/app/workers/cluster_install_app_worker.rb
+++ b/app/workers/cluster_install_app_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ClusterInstallAppWorker
   include ApplicationWorker
   include ClusterQueue
diff --git a/app/workers/cluster_provision_worker.rb b/app/workers/cluster_provision_worker.rb
index 1ab4de3b6479b6c82077acfc1f03e9d3ad8211ef..59de7903c1cdbb830cee602c62bdb13f3d1cd4d6 100644
--- a/app/workers/cluster_provision_worker.rb
+++ b/app/workers/cluster_provision_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ClusterProvisionWorker
   include ApplicationWorker
   include ClusterQueue
diff --git a/app/workers/cluster_wait_for_app_installation_worker.rb b/app/workers/cluster_wait_for_app_installation_worker.rb
index d564d5e48bf7abeb1788cdd9fa19ef0234857324..e8d7e52f70f9658a7d7dded787fd44f2ea745e9b 100644
--- a/app/workers/cluster_wait_for_app_installation_worker.rb
+++ b/app/workers/cluster_wait_for_app_installation_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ClusterWaitForAppInstallationWorker
   include ApplicationWorker
   include ClusterQueue
diff --git a/app/workers/cluster_wait_for_ingress_ip_address_worker.rb b/app/workers/cluster_wait_for_ingress_ip_address_worker.rb
index 8ba5951750c7818c067bde5911ecb6637c6db1d6..6865384df44755b559423dd6cf930b755bffe4a4 100644
--- a/app/workers/cluster_wait_for_ingress_ip_address_worker.rb
+++ b/app/workers/cluster_wait_for_ingress_ip_address_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ClusterWaitForIngressIpAddressWorker
   include ApplicationWorker
   include ClusterQueue
diff --git a/app/workers/create_gpg_signature_worker.rb b/app/workers/create_gpg_signature_worker.rb
index f371731f68c95180e2ca547a6a0855a3ee2e19fd..a2da1bda11fc507fbd04a5ad8f0e38a9b09035ab 100644
--- a/app/workers/create_gpg_signature_worker.rb
+++ b/app/workers/create_gpg_signature_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateGpgSignatureWorker
   include ApplicationWorker
 
diff --git a/app/workers/create_note_diff_file_worker.rb b/app/workers/create_note_diff_file_worker.rb
index 624b638a24e5d1561a3dc2baacefade7756e1d57..0850250f7e3ec9ce682975ee37fbc4d63b9ab321 100644
--- a/app/workers/create_note_diff_file_worker.rb
+++ b/app/workers/create_note_diff_file_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreateNoteDiffFileWorker
   include ApplicationWorker
 
diff --git a/app/workers/create_pipeline_worker.rb b/app/workers/create_pipeline_worker.rb
index c3ac35e54f54499da8b4889f497f51783ea429ca..037b4a57d4b24fa4a0e38ae259652c52a80e1e6d 100644
--- a/app/workers/create_pipeline_worker.rb
+++ b/app/workers/create_pipeline_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CreatePipelineWorker
   include ApplicationWorker
   include PipelineQueue
diff --git a/app/workers/delete_merged_branches_worker.rb b/app/workers/delete_merged_branches_worker.rb
index 07cd1f02fb59bb10923212daeebc55236e9fc60d..017d7fd1cb033d50fe89b1bbdb46d7f5df0683d8 100644
--- a/app/workers/delete_merged_branches_worker.rb
+++ b/app/workers/delete_merged_branches_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class DeleteMergedBranchesWorker
   include ApplicationWorker
 
diff --git a/app/workers/delete_user_worker.rb b/app/workers/delete_user_worker.rb
index 6c431b02979dffcce4cc5e147a16c28557c06a0c..4d0295f8d2e339887ec8a5ce2446154d74f0d33d 100644
--- a/app/workers/delete_user_worker.rb
+++ b/app/workers/delete_user_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class DeleteUserWorker
   include ApplicationWorker
 
diff --git a/app/workers/email_receiver_worker.rb b/app/workers/email_receiver_worker.rb
index dd8a6cbbef1eaf27f82ddce69237c1a8c209e2a3..f9f0efb302ad43dc637016ae0655e8d3063b5c34 100644
--- a/app/workers/email_receiver_worker.rb
+++ b/app/workers/email_receiver_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class EmailReceiverWorker
   include ApplicationWorker
 
diff --git a/app/workers/emails_on_push_worker.rb b/app/workers/emails_on_push_worker.rb
index 2a4d65b5cb3b18f15a6ab495db2c91c27920314f..8d0cfc73ccd6c51fa6f8fa0f984150cddae640fd 100644
--- a/app/workers/emails_on_push_worker.rb
+++ b/app/workers/emails_on_push_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class EmailsOnPushWorker
   include ApplicationWorker
 
diff --git a/app/workers/expire_build_artifacts_worker.rb b/app/workers/expire_build_artifacts_worker.rb
index 87e5dca01fd9dd55f0a59527273e58d2d5fdb4c6..5d3a9a39b931523098dcaf85f471fb3d36deb902 100644
--- a/app/workers/expire_build_artifacts_worker.rb
+++ b/app/workers/expire_build_artifacts_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ExpireBuildArtifactsWorker
   include ApplicationWorker
   include CronjobQueue
diff --git a/app/workers/expire_build_instance_artifacts_worker.rb b/app/workers/expire_build_instance_artifacts_worker.rb
index 234b4357cf7fe2d5486ca126ac694992c0acaa67..3b57ecb36e316ddd57501ebbead13de7860fe866 100644
--- a/app/workers/expire_build_instance_artifacts_worker.rb
+++ b/app/workers/expire_build_instance_artifacts_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ExpireBuildInstanceArtifactsWorker
   include ApplicationWorker
 
diff --git a/app/workers/expire_job_cache_worker.rb b/app/workers/expire_job_cache_worker.rb
index 7217364a9f220c1957a95f62d7495143d3c8ecfa..14a57b90114c7fa3bbe660851637574d0363c153 100644
--- a/app/workers/expire_job_cache_worker.rb
+++ b/app/workers/expire_job_cache_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ExpireJobCacheWorker
   include ApplicationWorker
   include PipelineQueue
diff --git a/app/workers/expire_pipeline_cache_worker.rb b/app/workers/expire_pipeline_cache_worker.rb
index db73d37868a3f82c454a5258cb8a5b6eb709b668..992fc63c4516376e976c71b6094cf158b314088c 100644
--- a/app/workers/expire_pipeline_cache_worker.rb
+++ b/app/workers/expire_pipeline_cache_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ExpirePipelineCacheWorker
   include ApplicationWorker
   include PipelineQueue
diff --git a/app/workers/git_garbage_collect_worker.rb b/app/workers/git_garbage_collect_worker.rb
index ae5c5fac83456b45fbe2f5d3c9bc146e86322760..fd49bc18161381af37dcdb80e418ef91f06ec6f5 100644
--- a/app/workers/git_garbage_collect_worker.rb
+++ b/app/workers/git_garbage_collect_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class GitGarbageCollectWorker
   include ApplicationWorker
 
diff --git a/app/workers/gitlab_shell_worker.rb b/app/workers/gitlab_shell_worker.rb
index a0028e41332a808228762ca7b176ad905bc0d9ef..0e4d40acc5c89d61a07e152ee244c3bee2b1dfed 100644
--- a/app/workers/gitlab_shell_worker.rb
+++ b/app/workers/gitlab_shell_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class GitlabShellWorker
   include ApplicationWorker
   include Gitlab::ShellAdapter
diff --git a/app/workers/gitlab_usage_ping_worker.rb b/app/workers/gitlab_usage_ping_worker.rb
index 6dd281b1147d5d6c55f4a44bc1b491ba74e95062..b75e724ca98dfac648d225ca622a0f96257a9391 100644
--- a/app/workers/gitlab_usage_ping_worker.rb
+++ b/app/workers/gitlab_usage_ping_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class GitlabUsagePingWorker
   LEASE_TIMEOUT = 86400
 
diff --git a/app/workers/group_destroy_worker.rb b/app/workers/group_destroy_worker.rb
index 509bd09dc2e81a4742a42684f08934e1a40a223b..b4a3ddcae51a5a49112b0d8875db733a69c4c397 100644
--- a/app/workers/group_destroy_worker.rb
+++ b/app/workers/group_destroy_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class GroupDestroyWorker
   include ApplicationWorker
   include ExceptionBacktrace
diff --git a/app/workers/import_export_project_cleanup_worker.rb b/app/workers/import_export_project_cleanup_worker.rb
index 9788c8df3a3fa4308a1ac664e14d4348cc312a98..da3debdeede6c37099f3d367143ae4ed79c5258f 100644
--- a/app/workers/import_export_project_cleanup_worker.rb
+++ b/app/workers/import_export_project_cleanup_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ImportExportProjectCleanupWorker
   include ApplicationWorker
   include CronjobQueue
diff --git a/app/workers/invalid_gpg_signature_update_worker.rb b/app/workers/invalid_gpg_signature_update_worker.rb
index 6774ab307c602c15a03398e105e3bc291b7a2e6d..4724ab7ad985a31597166266365ac32a4031edfb 100644
--- a/app/workers/invalid_gpg_signature_update_worker.rb
+++ b/app/workers/invalid_gpg_signature_update_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class InvalidGpgSignatureUpdateWorker
   include ApplicationWorker
 
diff --git a/app/workers/irker_worker.rb b/app/workers/irker_worker.rb
index 9ae5456be4cc3f5d51d001866ee9fe75643c216f..29631c6b7ac68300ac36c123c28f3dde4ee0eb37 100644
--- a/app/workers/irker_worker.rb
+++ b/app/workers/irker_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'json'
 require 'socket'
 
@@ -69,8 +71,8 @@ class IrkerWorker
     newbranch = "#{Gitlab.config.gitlab.url}/#{repo_path}/branches"
     newbranch = "\x0302\x1f#{newbranch}\x0f" if @colors
 
-    privmsg = "[#{repo_name}] #{committer} has created a new branch "
-    privmsg += "#{branch}: #{newbranch}"
+    privmsg = "[#{repo_name}] #{committer} has created a new branch " \
+              "#{branch}: #{newbranch}"
     sendtoirker privmsg
   end
 
@@ -112,9 +114,7 @@ class IrkerWorker
     url = compare_url data, project.full_path
     commits = colorize_commits data['total_commits_count']
 
-    new_commits = 'new commit'
-    new_commits += 's' if data['total_commits_count'] > 1
-
+    new_commits = 'new commit'.pluralize(data['total_commits_count'])
     sendtoirker "[#{repo}] #{committer} pushed #{commits} #{new_commits} " \
                 "to #{branch}: #{url}"
   end
@@ -122,8 +122,8 @@ class IrkerWorker
   def compare_url(data, repo_path)
     sha1 = Commit.truncate_sha(data['before'])
     sha2 = Commit.truncate_sha(data['after'])
-    compare_url = "#{Gitlab.config.gitlab.url}/#{repo_path}/compare"
-    compare_url += "/#{sha1}...#{sha2}"
+    compare_url = "#{Gitlab.config.gitlab.url}/#{repo_path}/compare" \
+                  "/#{sha1}...#{sha2}"
     colorize_url compare_url
   end
 
@@ -144,8 +144,7 @@ class IrkerWorker
   def files_count(commit)
     diff_size = commit.raw_deltas.size
 
-    files = "#{diff_size} file"
-    files += 's' if diff_size > 1
+    files = "#{diff_size} file".pluralize(diff_size)
     files
   end
 
diff --git a/app/workers/issue_due_scheduler_worker.rb b/app/workers/issue_due_scheduler_worker.rb
index 16ab5d069e020485a7822153e29f57924691b4d0..c04a2d75e0b23a9dcf2f99393cacd56028e3a276 100644
--- a/app/workers/issue_due_scheduler_worker.rb
+++ b/app/workers/issue_due_scheduler_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class IssueDueSchedulerWorker
   include ApplicationWorker
   include CronjobQueue
diff --git a/app/workers/merge_worker.rb b/app/workers/merge_worker.rb
index ba832fe30c6b2baa81237c1de847063cc6087932..ee864b733cd83c5a348ddd9347cade9e54b57369 100644
--- a/app/workers/merge_worker.rb
+++ b/app/workers/merge_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class MergeWorker
   include ApplicationWorker
 
diff --git a/app/workers/namespaceless_project_destroy_worker.rb b/app/workers/namespaceless_project_destroy_worker.rb
index adb25c2a170582d1203366c79123f06274a40958..d9df42c9e1701a6cb64fc9033e380672c53df95a 100644
--- a/app/workers/namespaceless_project_destroy_worker.rb
+++ b/app/workers/namespaceless_project_destroy_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Worker to destroy projects that do not have a namespace
 #
 # It destroys everything it can without having the info about the namespace it
diff --git a/app/workers/new_issue_worker.rb b/app/workers/new_issue_worker.rb
index 3bc030f9c620fa94e9635590136097f2c5d6043d..85b53973f565fa5510577e262424f63ee8d4d3b8 100644
--- a/app/workers/new_issue_worker.rb
+++ b/app/workers/new_issue_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class NewIssueWorker
   include ApplicationWorker
   include NewIssuable
diff --git a/app/workers/new_merge_request_worker.rb b/app/workers/new_merge_request_worker.rb
index bda2a0ab59da61b7f64ccbbb70a52e89d1dea051..5d8b8904502bc80780570ceeaa7c1e933c5c3693 100644
--- a/app/workers/new_merge_request_worker.rb
+++ b/app/workers/new_merge_request_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class NewMergeRequestWorker
   include ApplicationWorker
   include NewIssuable
diff --git a/app/workers/new_note_worker.rb b/app/workers/new_note_worker.rb
index 67c54fbf10e05a127386c8129bd7cdc02fbd19ab..74f34dcf9aa9e515ab596db84a2d2c778d9ad9f1 100644
--- a/app/workers/new_note_worker.rb
+++ b/app/workers/new_note_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class NewNoteWorker
   include ApplicationWorker
 
diff --git a/app/workers/object_storage_upload_worker.rb b/app/workers/object_storage_upload_worker.rb
index 5c80f34069c2412f961f8941f33b2127f053a10d..f17980a83d8837e17130129f3da482b848916075 100644
--- a/app/workers/object_storage_upload_worker.rb
+++ b/app/workers/object_storage_upload_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # @Deprecated - remove once the `object_storage_upload` queue is empty
 # The queue has been renamed `object_storage:object_storage_background_upload`
 #
diff --git a/app/workers/pages_domain_verification_cron_worker.rb b/app/workers/pages_domain_verification_cron_worker.rb
index a3ff4bd2101138c41cdbc1c79850c2cc33199c3c..92d62a15aee649c925aedbbc2865dac03610c4f6 100644
--- a/app/workers/pages_domain_verification_cron_worker.rb
+++ b/app/workers/pages_domain_verification_cron_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PagesDomainVerificationCronWorker
   include ApplicationWorker
   include CronjobQueue
diff --git a/app/workers/pages_domain_verification_worker.rb b/app/workers/pages_domain_verification_worker.rb
index 2e93489113cbb6295bb3c79beb5e1f4e9352cd9e..4610b68818952d27573d5852013b6339b5bbd9dd 100644
--- a/app/workers/pages_domain_verification_worker.rb
+++ b/app/workers/pages_domain_verification_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PagesDomainVerificationWorker
   include ApplicationWorker
 
diff --git a/app/workers/pages_worker.rb b/app/workers/pages_worker.rb
index 66a0ff83bef28d9d64e74db814d4d1fa889b8203..13a6576a30150b86f394dca9d0ac47738e976296 100644
--- a/app/workers/pages_worker.rb
+++ b/app/workers/pages_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PagesWorker
   include ApplicationWorker
 
diff --git a/app/workers/pipeline_hooks_worker.rb b/app/workers/pipeline_hooks_worker.rb
index c94918ff4eeba7dd21fd39b999282e4446107d2e..58023e0af1b115cdf3a7064b2b9f2b1348bf6651 100644
--- a/app/workers/pipeline_hooks_worker.rb
+++ b/app/workers/pipeline_hooks_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PipelineHooksWorker
   include ApplicationWorker
   include PipelineQueue
diff --git a/app/workers/pipeline_metrics_worker.rb b/app/workers/pipeline_metrics_worker.rb
index d46d1f122fcfa72624fed7e5aba2ab53475029a3..a97019b100aa5c91cb0b82f8ee65834f491383d1 100644
--- a/app/workers/pipeline_metrics_worker.rb
+++ b/app/workers/pipeline_metrics_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PipelineMetricsWorker
   include ApplicationWorker
   include PipelineQueue
diff --git a/app/workers/pipeline_notification_worker.rb b/app/workers/pipeline_notification_worker.rb
index a9a1168a6e3a0d8cddee5790c4ea1c0b38a4f2bf..3a8846b37473cef184f0787c2eac37ae0bfbda42 100644
--- a/app/workers/pipeline_notification_worker.rb
+++ b/app/workers/pipeline_notification_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PipelineNotificationWorker
   include ApplicationWorker
   include PipelineQueue
diff --git a/app/workers/pipeline_process_worker.rb b/app/workers/pipeline_process_worker.rb
index 24424b3f472cb7bf8bbf7307133cd6a6f5aaa48c..83744c5338a4b68a29018f67558112cdf9e3817d 100644
--- a/app/workers/pipeline_process_worker.rb
+++ b/app/workers/pipeline_process_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PipelineProcessWorker
   include ApplicationWorker
   include PipelineQueue
diff --git a/app/workers/pipeline_schedule_worker.rb b/app/workers/pipeline_schedule_worker.rb
index c49758878a4cc5a036cd62902cfbee8be1d8ccda..a18157577355a158c42a0f194845432b31658bdf 100644
--- a/app/workers/pipeline_schedule_worker.rb
+++ b/app/workers/pipeline_schedule_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PipelineScheduleWorker
   include ApplicationWorker
   include CronjobQueue
diff --git a/app/workers/pipeline_success_worker.rb b/app/workers/pipeline_success_worker.rb
index 2ab0739a17f5e02a93bbc23bdf5def208e81a5e4..68e9af6a619e946e201d979d0de7b62a91b60124 100644
--- a/app/workers/pipeline_success_worker.rb
+++ b/app/workers/pipeline_success_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PipelineSuccessWorker
   include ApplicationWorker
   include PipelineQueue
diff --git a/app/workers/pipeline_update_worker.rb b/app/workers/pipeline_update_worker.rb
index fc9da2d45b113fc73852e6bfab85d8ae810ca8e1..c33468c1f146d2e800f68165891e55148efb7764 100644
--- a/app/workers/pipeline_update_worker.rb
+++ b/app/workers/pipeline_update_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PipelineUpdateWorker
   include ApplicationWorker
   include PipelineQueue
diff --git a/app/workers/plugin_worker.rb b/app/workers/plugin_worker.rb
index bfcc683d99a8b2442ac8fc323f7619b6675d500b..c293e28be4a7eb264e0a3d859a3cd0df2ffb6ba6 100644
--- a/app/workers/plugin_worker.rb
+++ b/app/workers/plugin_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PluginWorker
   include ApplicationWorker
 
diff --git a/app/workers/post_receive.rb b/app/workers/post_receive.rb
index f88b3fdbfb145d8b36305a73fb14ba761df55ab2..09a594cdb4eabcc4b4fa0e5d1907281cad159dbb 100644
--- a/app/workers/post_receive.rb
+++ b/app/workers/post_receive.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PostReceive
   include ApplicationWorker
 
diff --git a/app/workers/process_commit_worker.rb b/app/workers/process_commit_worker.rb
index 201e7f332b4c39c90788c1e4808c3b816a19c6db..ed39b4a1ea837881bee4a89160636227615ec406 100644
--- a/app/workers/process_commit_worker.rb
+++ b/app/workers/process_commit_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Worker for processing individiual commit messages pushed to a repository.
 #
 # Jobs for this worker are scheduled for every commit that is being pushed. As a
diff --git a/app/workers/project_cache_worker.rb b/app/workers/project_cache_worker.rb
index a993b4b2680f251f20caea957b5ebafc0221c4e3..b0e1d8837d9c0812ef202e87632bf0f827994119 100644
--- a/app/workers/project_cache_worker.rb
+++ b/app/workers/project_cache_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Worker for updating any project specific caches.
 class ProjectCacheWorker
   include ApplicationWorker
diff --git a/app/workers/project_destroy_worker.rb b/app/workers/project_destroy_worker.rb
index 1ba854ca4cb6c4b4d0b103189c5aa0bc41b12982..4447e8672400d6f5c5e4c30404368a538539bfa5 100644
--- a/app/workers/project_destroy_worker.rb
+++ b/app/workers/project_destroy_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ProjectDestroyWorker
   include ApplicationWorker
   include ExceptionBacktrace
diff --git a/app/workers/project_export_worker.rb b/app/workers/project_export_worker.rb
index c3d84bb0b93bf18bc6865d4024163ca6aa6189c2..ed9da39c7c39fb39de5324af454e23fbc0dd9ff5 100644
--- a/app/workers/project_export_worker.rb
+++ b/app/workers/project_export_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ProjectExportWorker
   include ApplicationWorker
   include ExceptionBacktrace
diff --git a/app/workers/project_migrate_hashed_storage_worker.rb b/app/workers/project_migrate_hashed_storage_worker.rb
index d01eb744e5d5bcbd11bd263ee8a796f907b2211f..9e4d66250a49580bc2b58bdfd118b2ace9bd4a55 100644
--- a/app/workers/project_migrate_hashed_storage_worker.rb
+++ b/app/workers/project_migrate_hashed_storage_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ProjectMigrateHashedStorageWorker
   include ApplicationWorker
 
diff --git a/app/workers/project_service_worker.rb b/app/workers/project_service_worker.rb
index 75c4b8b36632e231a7bf363a3e44c923b1ff8158..a0bc9288cf043974fd397d9d150dc2ee7e8642c1 100644
--- a/app/workers/project_service_worker.rb
+++ b/app/workers/project_service_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ProjectServiceWorker
   include ApplicationWorker
 
diff --git a/app/workers/propagate_service_template_worker.rb b/app/workers/propagate_service_template_worker.rb
index 635a97c99afc89e394489b81f25771bf633f5149..c9da1cae255997584649fe04c86d581f55ce7a64 100644
--- a/app/workers/propagate_service_template_worker.rb
+++ b/app/workers/propagate_service_template_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Worker for updating any project specific caches.
 class PropagateServiceTemplateWorker
   include ApplicationWorker
diff --git a/app/workers/prune_old_events_worker.rb b/app/workers/prune_old_events_worker.rb
index 5ff62ab1369e7ce9c8386ab3ca184f2b28dafa8d..c1d05ebbcfd3e3267b28b13a4192663cbd6cfa13 100644
--- a/app/workers/prune_old_events_worker.rb
+++ b/app/workers/prune_old_events_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class PruneOldEventsWorker
   include ApplicationWorker
   include CronjobQueue
diff --git a/app/workers/reactive_caching_worker.rb b/app/workers/reactive_caching_worker.rb
index ef3ddb9024bacf8106a0ff33f40de5e50bdcc607..9b331f15dc5f7fd5add6c74cd32222fa504a4808 100644
--- a/app/workers/reactive_caching_worker.rb
+++ b/app/workers/reactive_caching_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ReactiveCachingWorker
   include ApplicationWorker
 
diff --git a/app/workers/rebase_worker.rb b/app/workers/rebase_worker.rb
index 090987778a2d28f87b4c6d41a203cfb035d8cfed..a6baebc144308cfcaf9694b787268d9c0db1f2bf 100644
--- a/app/workers/rebase_worker.rb
+++ b/app/workers/rebase_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class RebaseWorker
   include ApplicationWorker
 
diff --git a/app/workers/remove_expired_group_links_worker.rb b/app/workers/remove_expired_group_links_worker.rb
index 7e64c3070a89cf33cd587dedf97276bc32a8bd8b..6b8b972a440c738ac302066e3fe718b8c022ecaf 100644
--- a/app/workers/remove_expired_group_links_worker.rb
+++ b/app/workers/remove_expired_group_links_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class RemoveExpiredGroupLinksWorker
   include ApplicationWorker
   include CronjobQueue
diff --git a/app/workers/remove_expired_members_worker.rb b/app/workers/remove_expired_members_worker.rb
index 68960f72bf670398bc4b25699bf26e36a4af2020..41913900571ee3d211cd8ba2df5bc25672ffacae 100644
--- a/app/workers/remove_expired_members_worker.rb
+++ b/app/workers/remove_expired_members_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class RemoveExpiredMembersWorker
   include ApplicationWorker
   include CronjobQueue
diff --git a/app/workers/remove_old_web_hook_logs_worker.rb b/app/workers/remove_old_web_hook_logs_worker.rb
index 87fed42d7ce203107c4f2c2547c14ce8ca38a7c0..17140ac44500dfb40857cf160375a13b097c5d4f 100644
--- a/app/workers/remove_old_web_hook_logs_worker.rb
+++ b/app/workers/remove_old_web_hook_logs_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class RemoveOldWebHookLogsWorker
   include ApplicationWorker
   include CronjobQueue
diff --git a/app/workers/remove_unreferenced_lfs_objects_worker.rb b/app/workers/remove_unreferenced_lfs_objects_worker.rb
index 8daf079fc3160179cf43a6fa06f8dd6bfc7e5bc9..95e7a9f537f5f7dfc04a06e5b4777e018d0a8287 100644
--- a/app/workers/remove_unreferenced_lfs_objects_worker.rb
+++ b/app/workers/remove_unreferenced_lfs_objects_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class RemoveUnreferencedLfsObjectsWorker
   include ApplicationWorker
   include CronjobQueue
diff --git a/app/workers/repository_archive_cache_worker.rb b/app/workers/repository_archive_cache_worker.rb
index 86a258cf94f3f6fc05cb38c77ae48be38c124696..c1dff8ced9077bd766fbc9db768e0b242dc61b43 100644
--- a/app/workers/repository_archive_cache_worker.rb
+++ b/app/workers/repository_archive_cache_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class RepositoryArchiveCacheWorker
   include ApplicationWorker
   include CronjobQueue
diff --git a/app/workers/repository_fork_worker.rb b/app/workers/repository_fork_worker.rb
index dbb215f1964ce0b16ebc4c9e1a8e017680e9d870..5ef9b744db3908233de237eb4d94862a95391b2b 100644
--- a/app/workers/repository_fork_worker.rb
+++ b/app/workers/repository_fork_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class RepositoryForkWorker
   include ApplicationWorker
   include Gitlab::ShellAdapter
diff --git a/app/workers/repository_import_worker.rb b/app/workers/repository_import_worker.rb
index d79b5ee5346fa02117f4cc1ce4001f7ce57ed0d0..25fec542ac7aa8b8644e4e1695857bd2e40160b2 100644
--- a/app/workers/repository_import_worker.rb
+++ b/app/workers/repository_import_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class RepositoryImportWorker
   include ApplicationWorker
   include ExceptionBacktrace
diff --git a/app/workers/repository_remove_remote_worker.rb b/app/workers/repository_remove_remote_worker.rb
index 1c19b604b77898c2fe8b874c788e0af721b79d33..a85e9fa93948627b271c10507a0c9aaf313717a0 100644
--- a/app/workers/repository_remove_remote_worker.rb
+++ b/app/workers/repository_remove_remote_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class RepositoryRemoveRemoteWorker
   include ApplicationWorker
   include ExclusiveLeaseGuard
diff --git a/app/workers/repository_update_remote_mirror_worker.rb b/app/workers/repository_update_remote_mirror_worker.rb
index bb963979e88c47537587e7cd8da47fcbb7bbda3c..9d4e67deb9cc2101f3d2d2ae43cf45ff90f1ca28 100644
--- a/app/workers/repository_update_remote_mirror_worker.rb
+++ b/app/workers/repository_update_remote_mirror_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class RepositoryUpdateRemoteMirrorWorker
   UpdateAlreadyInProgressError = Class.new(StandardError)
   UpdateError = Class.new(StandardError)
diff --git a/app/workers/requests_profiles_worker.rb b/app/workers/requests_profiles_worker.rb
index 55c236e9e9de37d76f3114e4fa3e1d0835b7ac1f..ae022d43e2976bf1c29b0a40e04c49f3f64ed3ce 100644
--- a/app/workers/requests_profiles_worker.rb
+++ b/app/workers/requests_profiles_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class RequestsProfilesWorker
   include ApplicationWorker
   include CronjobQueue
diff --git a/app/workers/run_pipeline_schedule_worker.rb b/app/workers/run_pipeline_schedule_worker.rb
index 8f5138fc873998a6dba8f95f80ae13bed6f8383f..1f6cb18c812ea24686ee5b665ee8b5d068daefcf 100644
--- a/app/workers/run_pipeline_schedule_worker.rb
+++ b/app/workers/run_pipeline_schedule_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class RunPipelineScheduleWorker
   include ApplicationWorker
   include PipelineQueue
diff --git a/app/workers/schedule_update_user_activity_worker.rb b/app/workers/schedule_update_user_activity_worker.rb
index d93765775970cc0bd7905c423e48cd8d98c089c7..ff42fb8f0e5cd231c21ae2128540ac192c33660b 100644
--- a/app/workers/schedule_update_user_activity_worker.rb
+++ b/app/workers/schedule_update_user_activity_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ScheduleUpdateUserActivityWorker
   include ApplicationWorker
   include CronjobQueue
diff --git a/app/workers/stage_update_worker.rb b/app/workers/stage_update_worker.rb
index e4b683fca3352fa4e1c22ae31dbe610436b49e49..ec8c8e3689f3106e1d682bb010de3d266ed5a39c 100644
--- a/app/workers/stage_update_worker.rb
+++ b/app/workers/stage_update_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class StageUpdateWorker
   include ApplicationWorker
   include PipelineQueue
diff --git a/app/workers/storage_migrator_worker.rb b/app/workers/storage_migrator_worker.rb
index 0aff0c4c7c65fd7c6e0bb0a9e533792af82162a3..fa76fbac55c85f512ffa848978f910ea71b08752 100644
--- a/app/workers/storage_migrator_worker.rb
+++ b/app/workers/storage_migrator_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class StorageMigratorWorker
   include ApplicationWorker
 
diff --git a/app/workers/stuck_ci_jobs_worker.rb b/app/workers/stuck_ci_jobs_worker.rb
index 7ebf69bdc397d7f5b68f84fa87b7a0a8faded6d0..c78b7fac589c1c7a6c940d873d44ebbca1510e30 100644
--- a/app/workers/stuck_ci_jobs_worker.rb
+++ b/app/workers/stuck_ci_jobs_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class StuckCiJobsWorker
   include ApplicationWorker
   include CronjobQueue
diff --git a/app/workers/stuck_import_jobs_worker.rb b/app/workers/stuck_import_jobs_worker.rb
index 6fdd7592e74a6d1d6aa1c7881e78397c88eac3e6..79ce06dd66e0085951c3e250b9e0fce87fe0031d 100644
--- a/app/workers/stuck_import_jobs_worker.rb
+++ b/app/workers/stuck_import_jobs_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class StuckImportJobsWorker
   include ApplicationWorker
   include CronjobQueue
diff --git a/app/workers/stuck_merge_jobs_worker.rb b/app/workers/stuck_merge_jobs_worker.rb
index 16394293c79e916607ff07222d38d73414f41528..b0a62f76e94170ac607610805a0c5f7e4b2ccd3b 100644
--- a/app/workers/stuck_merge_jobs_worker.rb
+++ b/app/workers/stuck_merge_jobs_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class StuckMergeJobsWorker
   include ApplicationWorker
   include CronjobQueue
diff --git a/app/workers/system_hook_push_worker.rb b/app/workers/system_hook_push_worker.rb
index ceeaaf8d18994a778679cba4a7f774a260fe2a0b..15e369ebcfb1b5f45541fff1acead3a07d7b385d 100644
--- a/app/workers/system_hook_push_worker.rb
+++ b/app/workers/system_hook_push_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class SystemHookPushWorker
   include ApplicationWorker
 
diff --git a/app/workers/trending_projects_worker.rb b/app/workers/trending_projects_worker.rb
index 7eb65452a7dcfc604432213efb401ca61ec8cdc1..3297a1fe3d0826d52ad4fb0b2b8948662cec0854 100644
--- a/app/workers/trending_projects_worker.rb
+++ b/app/workers/trending_projects_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class TrendingProjectsWorker
   include ApplicationWorker
   include CronjobQueue
diff --git a/app/workers/update_head_pipeline_for_merge_request_worker.rb b/app/workers/update_head_pipeline_for_merge_request_worker.rb
index 76f84ff920f302480bed2b0eeac6c42fb07dc326..0487a3935662925502d554ce44dae9526bce2a29 100644
--- a/app/workers/update_head_pipeline_for_merge_request_worker.rb
+++ b/app/workers/update_head_pipeline_for_merge_request_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class UpdateHeadPipelineForMergeRequestWorker
   include ApplicationWorker
   include PipelineQueue
diff --git a/app/workers/update_merge_requests_worker.rb b/app/workers/update_merge_requests_worker.rb
index 74bb999327501bd02e15401df047e75b389b16c9..742841219b33296c66252094f6d1a6c16d60e4f4 100644
--- a/app/workers/update_merge_requests_worker.rb
+++ b/app/workers/update_merge_requests_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class UpdateMergeRequestsWorker
   include ApplicationWorker
 
diff --git a/app/workers/update_user_activity_worker.rb b/app/workers/update_user_activity_worker.rb
index 27ec5cd33fb52ae24f98e1fa366316c21664a639..15f01a703375e4330c36e0b6819a78700d1c91b9 100644
--- a/app/workers/update_user_activity_worker.rb
+++ b/app/workers/update_user_activity_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class UpdateUserActivityWorker
   include ApplicationWorker
 
diff --git a/app/workers/upload_checksum_worker.rb b/app/workers/upload_checksum_worker.rb
index 65d40336f18b43d19ce089c817cfcc2b46abc292..2a0536106d73c8c657fb1b22e7bbcd7fde32d99a 100644
--- a/app/workers/upload_checksum_worker.rb
+++ b/app/workers/upload_checksum_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class UploadChecksumWorker
   include ApplicationWorker
 
diff --git a/app/workers/wait_for_cluster_creation_worker.rb b/app/workers/wait_for_cluster_creation_worker.rb
index 19cdb279aaaf929edae868f7febb2f9ad0a7741e..8aa1d9290fd3b0201e284270d0d145926df3aeaa 100644
--- a/app/workers/wait_for_cluster_creation_worker.rb
+++ b/app/workers/wait_for_cluster_creation_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class WaitForClusterCreationWorker
   include ApplicationWorker
   include ClusterQueue
diff --git a/app/workers/web_hook_worker.rb b/app/workers/web_hook_worker.rb
index dfc3f33ad9d4b439c069086ef0600e78306ab29a..09219a24a16c2d29fdc63707258b442902df63a2 100644
--- a/app/workers/web_hook_worker.rb
+++ b/app/workers/web_hook_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class WebHookWorker
   include ApplicationWorker
 
diff --git a/changelogs/unreleased/frozen-string-app-workers.yml b/changelogs/unreleased/frozen-string-app-workers.yml
new file mode 100644
index 0000000000000000000000000000000000000000..48b50cc6ca4892faf66e2d83d5da0a87cdf0d476
--- /dev/null
+++ b/changelogs/unreleased/frozen-string-app-workers.yml
@@ -0,0 +1,5 @@
+---
+title: Enable frozen string in app/workers/*.rb
+merge_request: 19944
+author: gfyoung
+type: other