Enable more frozen string in lib/**/*.rb

Enables frozen for the following:

* lib/*.rb
* lib/banzai/**/*.rb
* lib/bitbucket/**/*.rb
* lib/constraints/**/*.rb
* lib/container_registry/**/*.rb
* lib/declarative_policy/**/*.rb

Partially addresses #47424.

102 files changed, 212 insertions, 5 deletions

diff --git a/lib/after_commit_queue.rb b/lib/after_commit_queue.rb
index a4d8507960e..6fb7985f955 100644
--- a/lib/after_commit_queue.rb
+++ b/lib/after_commit_queue.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module AfterCommitQueue
   extend ActiveSupport::Concern
 
diff --git a/lib/backup.rb b/lib/backup.rb
index e2c62af23ae..2712b33b4b4 100644
--- a/lib/backup.rb
+++ b/lib/backup.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Backup
   Error = Class.new(StandardError)
 end
diff --git a/lib/banzai.rb b/lib/banzai.rb
index 788f29a6c08..1eb41ff7133 100644
--- a/lib/banzai.rb
+++ b/lib/banzai.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Banzai
   # if you need to render markdown, then you probably need to post_process as well,
   # such as removing references that the current user doesn't have
diff --git a/lib/banzai/color_parser.rb b/lib/banzai/color_parser.rb
index 355c364b07b..6d01d51955c 100644
--- a/lib/banzai/color_parser.rb
+++ b/lib/banzai/color_parser.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Banzai
   module ColorParser
     ALPHA = /0(?:\.\d+)?|\.\d+|1(?:\.0+)?/ # 0.0..1.0
diff --git a/lib/banzai/commit_renderer.rb b/lib/banzai/commit_renderer.rb
index c351a155ae5..f346151a3c1 100644
--- a/lib/banzai/commit_renderer.rb
+++ b/lib/banzai/commit_renderer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Banzai
   module CommitRenderer
     ATTRIBUTES = [:description, :title].freeze
diff --git a/lib/banzai/cross_project_reference.rb b/lib/banzai/cross_project_reference.rb
index 43f913a8859..b7344808989 100644
--- a/lib/banzai/cross_project_reference.rb
+++ b/lib/banzai/cross_project_reference.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Banzai
   # Common methods for ReferenceFilters that support an optional cross-project
   # reference.
diff --git a/lib/banzai/filter.rb b/lib/banzai/filter.rb
index 3eb544dfef9..7d9766c906c 100644
--- a/lib/banzai/filter.rb
+++ b/lib/banzai/filter.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Banzai
   module Filter
     def self.[](name)
diff --git a/lib/banzai/filter/markdown_engines/common_mark.rb b/lib/banzai/filter/markdown_engines/common_mark.rb
index dbb25280849..e52c0d15b31 100644
--- a/lib/banzai/filter/markdown_engines/common_mark.rb
+++ b/lib/banzai/filter/markdown_engines/common_mark.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # `CommonMark` markdown engine for GitLab's Banzai markdown filter.
 # This module is used in Banzai::Filter::MarkdownFilter.
 # Used gem is `commonmarker` which is a ruby wrapper for libcmark (CommonMark parser)
diff --git a/lib/banzai/filter/markdown_engines/redcarpet.rb b/lib/banzai/filter/markdown_engines/redcarpet.rb
index ac99941fefa..ec150d041ff 100644
--- a/lib/banzai/filter/markdown_engines/redcarpet.rb
+++ b/lib/banzai/filter/markdown_engines/redcarpet.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # `Redcarpet` markdown engine for GitLab's Banzai markdown filter.
 # This module is used in Banzai::Filter::MarkdownFilter.
 # Used gem is `redcarpet` which is a ruby library for markdown processing.
diff --git a/lib/banzai/filter/wiki_link_filter/rewriter.rb b/lib/banzai/filter/wiki_link_filter/rewriter.rb
index 4bf80aff418..f4cc8beeb52 100644
--- a/lib/banzai/filter/wiki_link_filter/rewriter.rb
+++ b/lib/banzai/filter/wiki_link_filter/rewriter.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Banzai
   module Filter
     class WikiLinkFilter < HTML::Pipeline::Filter
diff --git a/lib/banzai/filter_array.rb b/lib/banzai/filter_array.rb
index 77835a14027..818af4643a7 100644
--- a/lib/banzai/filter_array.rb
+++ b/lib/banzai/filter_array.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Banzai
   class FilterArray < Array
     # Insert a value immediately after another value
diff --git a/lib/banzai/issuable_extractor.rb b/lib/banzai/issuable_extractor.rb
index ae7dc71e7eb..0a05d46db4c 100644
--- a/lib/banzai/issuable_extractor.rb
+++ b/lib/banzai/issuable_extractor.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Banzai
   # Extract references to issuables from multiple documents
 
diff --git a/lib/banzai/object_renderer.rb b/lib/banzai/object_renderer.rb
index 7137c1da57d..75661ffa233 100644
--- a/lib/banzai/object_renderer.rb
+++ b/lib/banzai/object_renderer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Banzai
   # Class for rendering multiple objects (e.g. Note instances) in a single pass,
   # using +render_field+ to benefit from caching in the database. Rendering and
diff --git a/lib/banzai/pipeline.rb b/lib/banzai/pipeline.rb
index 142a9962eb1..e8a81bebaa9 100644
--- a/lib/banzai/pipeline.rb
+++ b/lib/banzai/pipeline.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Banzai
   module Pipeline
     def self.[](name)
diff --git a/lib/banzai/pipeline/ascii_doc_pipeline.rb b/lib/banzai/pipeline/ascii_doc_pipeline.rb
index 1048b927cd3..cc4af280872 100644
--- a/lib/banzai/pipeline/ascii_doc_pipeline.rb
+++ b/lib/banzai/pipeline/ascii_doc_pipeline.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Banzai
   module Pipeline
     class AsciiDocPipeline < BasePipeline
diff --git a/lib/banzai/pipeline/atom_pipeline.rb b/lib/banzai/pipeline/atom_pipeline.rb
index 9694e4bc23f..13a342351b6 100644
--- a/lib/banzai/pipeline/atom_pipeline.rb
+++ b/lib/banzai/pipeline/atom_pipeline.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Banzai
   module Pipeline
     class AtomPipeline < FullPipeline
diff --git a/lib/banzai/pipeline/base_pipeline.rb b/lib/banzai/pipeline/base_pipeline.rb
index 3ae3bed570d..87d1cf9912f 100644
--- a/lib/banzai/pipeline/base_pipeline.rb
+++ b/lib/banzai/pipeline/base_pipeline.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Banzai
   module Pipeline
     class BasePipeline
diff --git a/lib/banzai/pipeline/broadcast_message_pipeline.rb b/lib/banzai/pipeline/broadcast_message_pipeline.rb
index 5dd572de3a1..a3d63e0aaf5 100644
--- a/lib/banzai/pipeline/broadcast_message_pipeline.rb
+++ b/lib/banzai/pipeline/broadcast_message_pipeline.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Banzai
   module Pipeline
     class BroadcastMessagePipeline < DescriptionPipeline
diff --git a/lib/banzai/pipeline/combined_pipeline.rb b/lib/banzai/pipeline/combined_pipeline.rb
index 60190f8d9dd..56b424dc8e0 100644
--- a/lib/banzai/pipeline/combined_pipeline.rb
+++ b/lib/banzai/pipeline/combined_pipeline.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Banzai
   module Pipeline
     module CombinedPipeline
diff --git a/lib/banzai/pipeline/commit_description_pipeline.rb b/lib/banzai/pipeline/commit_description_pipeline.rb
index 607c2731ed3..e8ec7453f0f 100644
--- a/lib/banzai/pipeline/commit_description_pipeline.rb
+++ b/lib/banzai/pipeline/commit_description_pipeline.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Banzai
   module Pipeline
     class CommitDescriptionPipeline < SingleLinePipeline
diff --git a/lib/banzai/pipeline/description_pipeline.rb b/lib/banzai/pipeline/description_pipeline.rb
index 042fb2e6e14..d5ff9b025cc 100644
--- a/lib/banzai/pipeline/description_pipeline.rb
+++ b/lib/banzai/pipeline/description_pipeline.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Banzai
   module Pipeline
     class DescriptionPipeline < FullPipeline
diff --git a/lib/banzai/pipeline/email_pipeline.rb b/lib/banzai/pipeline/email_pipeline.rb
index 8f5f144d582..2c08581ce0d 100644
--- a/lib/banzai/pipeline/email_pipeline.rb
+++ b/lib/banzai/pipeline/email_pipeline.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Banzai
   module Pipeline
     class EmailPipeline < FullPipeline
diff --git a/lib/banzai/pipeline/full_pipeline.rb b/lib/banzai/pipeline/full_pipeline.rb
index 3c974f73176..a5b1cbdd030 100644
--- a/lib/banzai/pipeline/full_pipeline.rb
+++ b/lib/banzai/pipeline/full_pipeline.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Banzai
   module Pipeline
     class FullPipeline < CombinedPipeline.new(PlainMarkdownPipeline, GfmPipeline)
diff --git a/lib/banzai/pipeline/gfm_pipeline.rb b/lib/banzai/pipeline/gfm_pipeline.rb
index bd34614f149..be75e34a673 100644
--- a/lib/banzai/pipeline/gfm_pipeline.rb
+++ b/lib/banzai/pipeline/gfm_pipeline.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Banzai
   module Pipeline
     class GfmPipeline < BasePipeline
diff --git a/lib/banzai/pipeline/markup_pipeline.rb b/lib/banzai/pipeline/markup_pipeline.rb
index c56d908009f..db79a22549c 100644
--- a/lib/banzai/pipeline/markup_pipeline.rb
+++ b/lib/banzai/pipeline/markup_pipeline.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Banzai
   module Pipeline
     class MarkupPipeline < BasePipeline
diff --git a/lib/banzai/pipeline/note_pipeline.rb b/lib/banzai/pipeline/note_pipeline.rb
index 7890f20f716..4480d7ede05 100644
--- a/lib/banzai/pipeline/note_pipeline.rb
+++ b/lib/banzai/pipeline/note_pipeline.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Banzai
   module Pipeline
     class NotePipeline < FullPipeline
diff --git a/lib/banzai/pipeline/plain_markdown_pipeline.rb b/lib/banzai/pipeline/plain_markdown_pipeline.rb
index 3f45db21869..b64f13cde47 100644
--- a/lib/banzai/pipeline/plain_markdown_pipeline.rb
+++ b/lib/banzai/pipeline/plain_markdown_pipeline.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Banzai
   module Pipeline
     class PlainMarkdownPipeline < BasePipeline
diff --git a/lib/banzai/pipeline/post_process_pipeline.rb b/lib/banzai/pipeline/post_process_pipeline.rb
index 0b2e584ef16..63a998a2c1f 100644
--- a/lib/banzai/pipeline/post_process_pipeline.rb
+++ b/lib/banzai/pipeline/post_process_pipeline.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Banzai
   module Pipeline
     class PostProcessPipeline < BasePipeline
diff --git a/lib/banzai/pipeline/pre_process_pipeline.rb b/lib/banzai/pipeline/pre_process_pipeline.rb
index 6cf219661d3..c937f783180 100644
--- a/lib/banzai/pipeline/pre_process_pipeline.rb
+++ b/lib/banzai/pipeline/pre_process_pipeline.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Banzai
   module Pipeline
     class PreProcessPipeline < BasePipeline
diff --git a/lib/banzai/pipeline/relative_link_pipeline.rb b/lib/banzai/pipeline/relative_link_pipeline.rb
index 270990e7ab4..88651892acc 100644
--- a/lib/banzai/pipeline/relative_link_pipeline.rb
+++ b/lib/banzai/pipeline/relative_link_pipeline.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Banzai
   module Pipeline
     class RelativeLinkPipeline < BasePipeline
diff --git a/lib/banzai/pipeline/single_line_pipeline.rb b/lib/banzai/pipeline/single_line_pipeline.rb
index cd5a6c8875c..61ff7b0bcce 100644
--- a/lib/banzai/pipeline/single_line_pipeline.rb
+++ b/lib/banzai/pipeline/single_line_pipeline.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Banzai
   module Pipeline
     class SingleLinePipeline < GfmPipeline
diff --git a/lib/banzai/pipeline/wiki_pipeline.rb b/lib/banzai/pipeline/wiki_pipeline.rb
index c37b8e71cb0..97a03895ff3 100644
--- a/lib/banzai/pipeline/wiki_pipeline.rb
+++ b/lib/banzai/pipeline/wiki_pipeline.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Banzai
   module Pipeline
     class WikiPipeline < FullPipeline
diff --git a/lib/banzai/querying.rb b/lib/banzai/querying.rb
index a19a05e8c0d..55aa5fa66c3 100644
--- a/lib/banzai/querying.rb
+++ b/lib/banzai/querying.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Banzai
   module Querying
     module_function
diff --git a/lib/banzai/redactor.rb b/lib/banzai/redactor.rb
index e77bee78496..7db5f5e1f7d 100644
--- a/lib/banzai/redactor.rb
+++ b/lib/banzai/redactor.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Banzai
   # Class for removing Markdown references a certain user is not allowed to
   # view.
diff --git a/lib/banzai/reference_extractor.rb b/lib/banzai/reference_extractor.rb
index 78588299c18..3fc3ae02088 100644
--- a/lib/banzai/reference_extractor.rb
+++ b/lib/banzai/reference_extractor.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Banzai
   # Extract possible GFM references from an arbitrary String for further processing.
   class ReferenceExtractor
diff --git a/lib/banzai/reference_parser.rb b/lib/banzai/reference_parser.rb
index 557bec4316e..efe15096f08 100644
--- a/lib/banzai/reference_parser.rb
+++ b/lib/banzai/reference_parser.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Banzai
   module ReferenceParser
     # Returns the reference parser class for the given type
diff --git a/lib/banzai/reference_parser/base_parser.rb b/lib/banzai/reference_parser/base_parser.rb
index 334ba97bfb3..8419769085a 100644
--- a/lib/banzai/reference_parser/base_parser.rb
+++ b/lib/banzai/reference_parser/base_parser.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Banzai
   module ReferenceParser
     # Base class for reference parsing classes.
diff --git a/lib/banzai/reference_parser/commit_parser.rb b/lib/banzai/reference_parser/commit_parser.rb
index 30dc87248b4..0bfb6a92020 100644
--- a/lib/banzai/reference_parser/commit_parser.rb
+++ b/lib/banzai/reference_parser/commit_parser.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Banzai
   module ReferenceParser
     class CommitParser < BaseParser
diff --git a/lib/banzai/reference_parser/commit_range_parser.rb b/lib/banzai/reference_parser/commit_range_parser.rb
index 2920e886938..480eefd5c4d 100644
--- a/lib/banzai/reference_parser/commit_range_parser.rb
+++ b/lib/banzai/reference_parser/commit_range_parser.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Banzai
   module ReferenceParser
     class CommitRangeParser < BaseParser
diff --git a/lib/banzai/reference_parser/directly_addressed_user_parser.rb b/lib/banzai/reference_parser/directly_addressed_user_parser.rb
index 77df9bbd024..1f18f82b916 100644
--- a/lib/banzai/reference_parser/directly_addressed_user_parser.rb
+++ b/lib/banzai/reference_parser/directly_addressed_user_parser.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Banzai
   module ReferenceParser
     class DirectlyAddressedUserParser < UserParser
diff --git a/lib/banzai/reference_parser/epic_parser.rb b/lib/banzai/reference_parser/epic_parser.rb
index 08b8a4c9a0f..7f366f0f8ab 100644
--- a/lib/banzai/reference_parser/epic_parser.rb
+++ b/lib/banzai/reference_parser/epic_parser.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Banzai
   module ReferenceParser
     # The actual parser is implemented in the EE mixin
diff --git a/lib/banzai/reference_parser/external_issue_parser.rb b/lib/banzai/reference_parser/external_issue_parser.rb
index 1802cd04854..029b09dcd25 100644
--- a/lib/banzai/reference_parser/external_issue_parser.rb
+++ b/lib/banzai/reference_parser/external_issue_parser.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Banzai
   module ReferenceParser
     class ExternalIssueParser < BaseParser
diff --git a/lib/banzai/reference_parser/issuable_parser.rb b/lib/banzai/reference_parser/issuable_parser.rb
index fad127d7e5b..f8c26288017 100644
--- a/lib/banzai/reference_parser/issuable_parser.rb
+++ b/lib/banzai/reference_parser/issuable_parser.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Banzai
   module ReferenceParser
     class IssuableParser < BaseParser
diff --git a/lib/banzai/reference_parser/issue_parser.rb b/lib/banzai/reference_parser/issue_parser.rb
index 7b5915899cf..97c7173ac0f 100644
--- a/lib/banzai/reference_parser/issue_parser.rb
+++ b/lib/banzai/reference_parser/issue_parser.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Banzai
   module ReferenceParser
     class IssueParser < IssuableParser
diff --git a/lib/banzai/reference_parser/label_parser.rb b/lib/banzai/reference_parser/label_parser.rb
index 30e2a012f09..398cc45fea0 100644
--- a/lib/banzai/reference_parser/label_parser.rb
+++ b/lib/banzai/reference_parser/label_parser.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Banzai
   module ReferenceParser
     class LabelParser < BaseParser
diff --git a/lib/banzai/reference_parser/merge_request_parser.rb b/lib/banzai/reference_parser/merge_request_parser.rb
index 9e5d55f72bc..e8147ac591a 100644
--- a/lib/banzai/reference_parser/merge_request_parser.rb
+++ b/lib/banzai/reference_parser/merge_request_parser.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Banzai
   module ReferenceParser
     class MergeRequestParser < IssuableParser
diff --git a/lib/banzai/reference_parser/milestone_parser.rb b/lib/banzai/reference_parser/milestone_parser.rb
index 68675abe22a..925d736fb9a 100644
--- a/lib/banzai/reference_parser/milestone_parser.rb
+++ b/lib/banzai/reference_parser/milestone_parser.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Banzai
   module ReferenceParser
     class MilestoneParser < BaseParser
diff --git a/lib/banzai/reference_parser/snippet_parser.rb b/lib/banzai/reference_parser/snippet_parser.rb
index 3ade168b566..6f6ac08de04 100644
--- a/lib/banzai/reference_parser/snippet_parser.rb
+++ b/lib/banzai/reference_parser/snippet_parser.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Banzai
   module ReferenceParser
     class SnippetParser < BaseParser
diff --git a/lib/banzai/reference_parser/user_parser.rb b/lib/banzai/reference_parser/user_parser.rb
index ceb7f1d165c..067b06b7590 100644
--- a/lib/banzai/reference_parser/user_parser.rb
+++ b/lib/banzai/reference_parser/user_parser.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Banzai
   module ReferenceParser
     class UserParser < BaseParser
diff --git a/lib/banzai/renderer.rb b/lib/banzai/renderer.rb
index 0050295eeda..c7239a5eaa6 100644
--- a/lib/banzai/renderer.rb
+++ b/lib/banzai/renderer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Banzai
   module Renderer
     # Convert a Markdown String into an HTML-safe String of HTML
diff --git a/lib/banzai/renderer/common_mark/html.rb b/lib/banzai/renderer/common_mark/html.rb
index 0b27316da1b..837665451a1 100644
--- a/lib/banzai/renderer/common_mark/html.rb
+++ b/lib/banzai/renderer/common_mark/html.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Banzai
   module Renderer
     module CommonMark
diff --git a/lib/banzai/renderer/redcarpet/html.rb b/lib/banzai/renderer/redcarpet/html.rb
index 30e815f1224..84931fdc784 100644
--- a/lib/banzai/renderer/redcarpet/html.rb
+++ b/lib/banzai/renderer/redcarpet/html.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Banzai
   module Renderer
     module Redcarpet
diff --git a/lib/banzai/request_store_reference_cache.rb b/lib/banzai/request_store_reference_cache.rb
index 9a9704f9837..91fb489b72d 100644
--- a/lib/banzai/request_store_reference_cache.rb
+++ b/lib/banzai/request_store_reference_cache.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Banzai
   module RequestStoreReferenceCache
     def cached_call(request_store_key, cache_key, path: [])
diff --git a/lib/bitbucket/client.rb b/lib/bitbucket/client.rb
index f8ee7e0f9ae..1343f424c51 100644
--- a/lib/bitbucket/client.rb
+++ b/lib/bitbucket/client.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Bitbucket
   class Client
     attr_reader :connection
diff --git a/lib/bitbucket/collection.rb b/lib/bitbucket/collection.rb
index a78495dbf5e..9c496daccaa 100644
--- a/lib/bitbucket/collection.rb
+++ b/lib/bitbucket/collection.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Bitbucket
   class Collection < Enumerator
     def initialize(paginator)
diff --git a/lib/bitbucket/connection.rb b/lib/bitbucket/connection.rb
index ba5a9e2f04c..0041634f9e3 100644
--- a/lib/bitbucket/connection.rb
+++ b/lib/bitbucket/connection.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Bitbucket
   class Connection
     DEFAULT_API_VERSION = '2.0'.freeze
diff --git a/lib/bitbucket/error/unauthorized.rb b/lib/bitbucket/error/unauthorized.rb
index efe10542f19..3cde11babee 100644
--- a/lib/bitbucket/error/unauthorized.rb
+++ b/lib/bitbucket/error/unauthorized.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Bitbucket
   module Error
     Unauthorized = Class.new(StandardError)
diff --git a/lib/bitbucket/page.rb b/lib/bitbucket/page.rb
index 2b0a3fe7b1a..7cc1342ad65 100644
--- a/lib/bitbucket/page.rb
+++ b/lib/bitbucket/page.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Bitbucket
   class Page
     attr_reader :attrs, :items
diff --git a/lib/bitbucket/paginator.rb b/lib/bitbucket/paginator.rb
index 135d0d55674..0d004592e67 100644
--- a/lib/bitbucket/paginator.rb
+++ b/lib/bitbucket/paginator.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Bitbucket
   class Paginator
     PAGE_LENGTH = 50 # The minimum length is 10 and the maximum is 100.
diff --git a/lib/bitbucket/representation/base.rb b/lib/bitbucket/representation/base.rb
index 800d5a075c6..bb8dcd91ad5 100644
--- a/lib/bitbucket/representation/base.rb
+++ b/lib/bitbucket/representation/base.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Bitbucket
   module Representation
     class Base
diff --git a/lib/bitbucket/representation/comment.rb b/lib/bitbucket/representation/comment.rb
index 4937aa9728f..1b8dc27793a 100644
--- a/lib/bitbucket/representation/comment.rb
+++ b/lib/bitbucket/representation/comment.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Bitbucket
   module Representation
     class Comment < Representation::Base
diff --git a/lib/bitbucket/representation/issue.rb b/lib/bitbucket/representation/issue.rb
index 44bcbc250b3..a88797cdab9 100644
--- a/lib/bitbucket/representation/issue.rb
+++ b/lib/bitbucket/representation/issue.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Bitbucket
   module Representation
     class Issue < Representation::Base
diff --git a/lib/bitbucket/representation/pull_request.rb b/lib/bitbucket/representation/pull_request.rb
index eebf8093380..6a0e8b354bf 100644
--- a/lib/bitbucket/representation/pull_request.rb
+++ b/lib/bitbucket/representation/pull_request.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Bitbucket
   module Representation
     class PullRequest < Representation::Base
diff --git a/lib/bitbucket/representation/pull_request_comment.rb b/lib/bitbucket/representation/pull_request_comment.rb
index c52acbc3ddc..34dbf9ad22d 100644
--- a/lib/bitbucket/representation/pull_request_comment.rb
+++ b/lib/bitbucket/representation/pull_request_comment.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Bitbucket
   module Representation
     class PullRequestComment < Comment
diff --git a/lib/bitbucket/representation/repo.rb b/lib/bitbucket/representation/repo.rb
index 59b0fda8e14..c5bfc91e43d 100644
--- a/lib/bitbucket/representation/repo.rb
+++ b/lib/bitbucket/representation/repo.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Bitbucket
   module Representation
     class Repo < Representation::Base
diff --git a/lib/bitbucket/representation/user.rb b/lib/bitbucket/representation/user.rb
index ba6b7667b49..2b45d751e70 100644
--- a/lib/bitbucket/representation/user.rb
+++ b/lib/bitbucket/representation/user.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Bitbucket
   module Representation
     class User < Representation::Base
diff --git a/lib/carrier_wave_string_file.rb b/lib/carrier_wave_string_file.rb
index 6c848902e4a..c9a64d9e631 100644
--- a/lib/carrier_wave_string_file.rb
+++ b/lib/carrier_wave_string_file.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class CarrierWaveStringFile < StringIO
   def original_filename
     ""
diff --git a/lib/constraints/feature_constrainer.rb b/lib/constraints/feature_constrainer.rb
index 05d48b0f25a..ca4376a9d38 100644
--- a/lib/constraints/feature_constrainer.rb
+++ b/lib/constraints/feature_constrainer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Constraints
   class FeatureConstrainer
     attr_reader :feature
diff --git a/lib/constraints/group_url_constrainer.rb b/lib/constraints/group_url_constrainer.rb
index 87649c50424..8a3f8d2faaf 100644
--- a/lib/constraints/group_url_constrainer.rb
+++ b/lib/constraints/group_url_constrainer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Constraints
   class GroupUrlConstrainer
     def matches?(request)
diff --git a/lib/constraints/project_url_constrainer.rb b/lib/constraints/project_url_constrainer.rb
index 32aea98f0f7..eadfbf7bc01 100644
--- a/lib/constraints/project_url_constrainer.rb
+++ b/lib/constraints/project_url_constrainer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Constraints
   class ProjectUrlConstrainer
     def matches?(request)
diff --git a/lib/constraints/user_url_constrainer.rb b/lib/constraints/user_url_constrainer.rb
index 8afa04d29a4..e763569cb2e 100644
--- a/lib/constraints/user_url_constrainer.rb
+++ b/lib/constraints/user_url_constrainer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Constraints
   class UserUrlConstrainer
     def matches?(request)
diff --git a/lib/container_registry/blob.rb b/lib/container_registry/blob.rb
index d5f85f9fcad..837b22c3082 100644
--- a/lib/container_registry/blob.rb
+++ b/lib/container_registry/blob.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ContainerRegistry
   class Blob
     attr_reader :repository, :config
diff --git a/lib/container_registry/client.rb b/lib/container_registry/client.rb
index 010ca1ec27b..c80f49f5ae0 100644
--- a/lib/container_registry/client.rb
+++ b/lib/container_registry/client.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'faraday'
 require 'faraday_middleware'
 
diff --git a/lib/container_registry/config.rb b/lib/container_registry/config.rb
index 589f9f4380a..740c0e13da0 100644
--- a/lib/container_registry/config.rb
+++ b/lib/container_registry/config.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ContainerRegistry
   class Config
     attr_reader :tag, :blob, :data
diff --git a/lib/container_registry/path.rb b/lib/container_registry/path.rb
index 1ab14c1c155..9b2a61cdedc 100644
--- a/lib/container_registry/path.rb
+++ b/lib/container_registry/path.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ContainerRegistry
   ##
   # Class responsible for extracting project and repository name from
diff --git a/lib/container_registry/registry.rb b/lib/container_registry/registry.rb
index f90d711474a..523364ac7c7 100644
--- a/lib/container_registry/registry.rb
+++ b/lib/container_registry/registry.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ContainerRegistry
   class Registry
     attr_reader :uri, :client, :path
diff --git a/lib/container_registry/tag.rb b/lib/container_registry/tag.rb
index c785bca4dad..8633e764f90 100644
--- a/lib/container_registry/tag.rb
+++ b/lib/container_registry/tag.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ContainerRegistry
   class Tag
     attr_reader :repository, :name
diff --git a/lib/declarative_policy.rb b/lib/declarative_policy.rb
index 10d34b0c6e7..5e22523e45a 100644
--- a/lib/declarative_policy.rb
+++ b/lib/declarative_policy.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_dependency 'declarative_policy/cache'
 require_dependency 'declarative_policy/condition'
 require_dependency 'declarative_policy/delegate_dsl'
diff --git a/lib/declarative_policy/base.rb b/lib/declarative_policy/base.rb
index da3fabba39b..cd6e1606f22 100644
--- a/lib/declarative_policy/base.rb
+++ b/lib/declarative_policy/base.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DeclarativePolicy
   class Base
     # A map of ability => list of rules together with :enable
diff --git a/lib/declarative_policy/cache.rb b/lib/declarative_policy/cache.rb
index 780d8f707bd..13006e56454 100644
--- a/lib/declarative_policy/cache.rb
+++ b/lib/declarative_policy/cache.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DeclarativePolicy
   module Cache
     class << self
diff --git a/lib/declarative_policy/condition.rb b/lib/declarative_policy/condition.rb
index 51c4a8b2bbe..b77f40b1093 100644
--- a/lib/declarative_policy/condition.rb
+++ b/lib/declarative_policy/condition.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DeclarativePolicy
   # A Condition is the data structure that is created by the
   # `condition` declaration on DeclarativePolicy::Base. It is
diff --git a/lib/declarative_policy/delegate_dsl.rb b/lib/declarative_policy/delegate_dsl.rb
index ca2eb98e3e8..67e3429b696 100644
--- a/lib/declarative_policy/delegate_dsl.rb
+++ b/lib/declarative_policy/delegate_dsl.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DeclarativePolicy
   # Used when the name of a delegate is mentioned in
   # the rule DSL.
diff --git a/lib/declarative_policy/policy_dsl.rb b/lib/declarative_policy/policy_dsl.rb
index c96049768a1..96741c0478e 100644
--- a/lib/declarative_policy/policy_dsl.rb
+++ b/lib/declarative_policy/policy_dsl.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DeclarativePolicy
   # The return value of a rule { ... } declaration.
   # Can call back to register rules with the containing
diff --git a/lib/declarative_policy/preferred_scope.rb b/lib/declarative_policy/preferred_scope.rb
index c77784cb49d..239780d8626 100644
--- a/lib/declarative_policy/preferred_scope.rb
+++ b/lib/declarative_policy/preferred_scope.rb
@@ -1,4 +1,7 @@
-module DeclarativePolicy # rubocop:disable Naming/FileName
+# rubocop:disable Naming/FileName
+# frozen_string_literal: true
+
+module DeclarativePolicy
   PREFERRED_SCOPE_KEY = :"DeclarativePolicy.preferred_scope"
 
   class << self
diff --git a/lib/declarative_policy/rule.rb b/lib/declarative_policy/rule.rb
index 407398cc770..f38f4f0a50f 100644
--- a/lib/declarative_policy/rule.rb
+++ b/lib/declarative_policy/rule.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DeclarativePolicy
   module Rule
     # A Rule is the object that results from the `rule` declaration,
diff --git a/lib/declarative_policy/rule_dsl.rb b/lib/declarative_policy/rule_dsl.rb
index 7254b08eda5..85da7f261fa 100644
--- a/lib/declarative_policy/rule_dsl.rb
+++ b/lib/declarative_policy/rule_dsl.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DeclarativePolicy
   # The DSL evaluation context inside rule { ... } blocks.
   # Responsible for creating and combining Rule objects.
diff --git a/lib/declarative_policy/runner.rb b/lib/declarative_policy/runner.rb
index fec672f4b8c..f739fe5e16e 100644
--- a/lib/declarative_policy/runner.rb
+++ b/lib/declarative_policy/runner.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DeclarativePolicy
   class Runner
     class State
diff --git a/lib/declarative_policy/step.rb b/lib/declarative_policy/step.rb
index 3469fe9f991..c289c17cc19 100644
--- a/lib/declarative_policy/step.rb
+++ b/lib/declarative_policy/step.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DeclarativePolicy
   # This object represents one step in the runtime decision of whether
   # an ability is allowed. It contains a Rule and a context (instance
diff --git a/lib/expand_variables.rb b/lib/expand_variables.rb
index 7b1533d0d32..c83cec9dc4a 100644
--- a/lib/expand_variables.rb
+++ b/lib/expand_variables.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ExpandVariables
   class << self
     def expand(value, variables)
diff --git a/lib/extracts_path.rb b/lib/extracts_path.rb
index e02d403f7b1..a340a276640 100644
--- a/lib/extracts_path.rb
+++ b/lib/extracts_path.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Module providing methods for dealing with separating a tree-ish string and a
 # file path string when combined in a request parameter
 module ExtractsPath
@@ -50,7 +52,9 @@ module ExtractsPath
       # branches and tags
 
       # Append a trailing slash if we only get a ref and no file path
-      id += '/' unless id.ends_with?('/')
+      unless id.ends_with?('/')
+        id = [id, '/'].join
+      end
 
       valid_refs = ref_names.select { |v| id.start_with?("#{v}/") }
 
@@ -151,9 +155,9 @@ module ExtractsPath
 
   # overriden in subclasses, do not remove
   def get_id
-    id = params[:id] || params[:ref]
-    id += "/" + params[:path] unless params[:path].blank?
-    id
+    id = [params[:id] || params[:ref]]
+    id << "/" + params[:path] unless params[:path].blank?
+    id.join
   end
 
   def ref_names
diff --git a/lib/feature.rb b/lib/feature.rb
index a8324d99c10..e048a443abc 100644
--- a/lib/feature.rb
+++ b/lib/feature.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'flipper/adapters/active_record'
 require 'flipper/adapters/active_support_cache_store'
 
diff --git a/lib/file_size_validator.rb b/lib/file_size_validator.rb
index 53aa8d04e5c..70a145cd5bd 100644
--- a/lib/file_size_validator.rb
+++ b/lib/file_size_validator.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class FileSizeValidator < ActiveModel::EachValidator
   MESSAGES = { is: :wrong_size, minimum: :size_too_small, maximum: :size_too_big }.freeze
   CHECKS   = { is: :==, minimum: :>=, maximum: :<= }.freeze
diff --git a/lib/forever.rb b/lib/forever.rb
index 7df17912544..0a37118fe68 100644
--- a/lib/forever.rb
+++ b/lib/forever.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Forever
   POSTGRESQL_DATE = DateTime.new(3000, 1, 1)
   MYSQL_DATE = DateTime.new(2038, 01, 19)
diff --git a/lib/gitlab.rb b/lib/gitlab.rb
index 7790534d5d7..2bb09684441 100644
--- a/lib/gitlab.rb
+++ b/lib/gitlab.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_dependency 'gitlab/popen'
 
 module Gitlab
diff --git a/lib/gt_one_coercion.rb b/lib/gt_one_coercion.rb
index ef2dc09767c..99be51bc8c6 100644
--- a/lib/gt_one_coercion.rb
+++ b/lib/gt_one_coercion.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class GtOneCoercion < Virtus::Attribute
   def coerce(value)
     [1, value.to_i].max
diff --git a/lib/milestone_array.rb b/lib/milestone_array.rb
index 4ed8485b36a..461e73e9670 100644
--- a/lib/milestone_array.rb
+++ b/lib/milestone_array.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module MilestoneArray
   class << self
     def sort(array, sort_method)
diff --git a/lib/mysql_zero_date.rb b/lib/mysql_zero_date.rb
index 64634f789da..216560148fa 100644
--- a/lib/mysql_zero_date.rb
+++ b/lib/mysql_zero_date.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Disable NO_ZERO_DATE mode for mysql in rails 5.
 # We use zero date as a default value
 # (config/initializers/active_record_mysql_timestamp.rb), in
diff --git a/lib/static_model.rb b/lib/static_model.rb
index 44673c2b5f6..86bf8d62f9a 100644
--- a/lib/static_model.rb
+++ b/lib/static_model.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Provides an ActiveRecord-like interface to a model whose data is not persisted to a database.
 module StaticModel
   extend ActiveSupport::Concern
diff --git a/lib/system_check.rb b/lib/system_check.rb
index 466c39904fa..7ffd7c03c5b 100644
--- a/lib/system_check.rb
+++ b/lib/system_check.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Library to perform System Checks
 #
 # Every Check is implemented as its own class inherited from SystemCheck::BaseCheck
diff --git a/lib/unfold_form.rb b/lib/unfold_form.rb
index fcd01503d1b..05bb3ed7f1c 100644
--- a/lib/unfold_form.rb
+++ b/lib/unfold_form.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_relative 'gt_one_coercion'
 
 class UnfoldForm
diff --git a/lib/uploaded_file.rb b/lib/uploaded_file.rb
index 53e5ac02e42..aae542f02ac 100644
--- a/lib/uploaded_file.rb
+++ b/lib/uploaded_file.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "tempfile"
 require "tmpdir"
 require "fileutils"
diff --git a/lib/version_check.rb b/lib/version_check.rb
index 91ad07feee5..ccf7bb493db 100644
--- a/lib/version_check.rb
+++ b/lib/version_check.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "base64"
 
 # This class is used to build image URL to