Add `Style/RedundantFreeze` to remove redudant `.freeze`

Since Rails 6.0 will support Ruby 2.4.1 or higher
`# frozen_string_literal: true` magic comment is enough to make string object frozen.
This magic comment is enabled by `Style/FrozenStringLiteralComment` cop.

* Exclude these files not to auto correct false positive `Regexp#freeze`
 - 'actionpack/lib/action_dispatch/journey/router/utils.rb'
 - 'activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb'

It has been fixed by https://github.com/rubocop-hq/rubocop/pull/6333
Once the newer version of RuboCop released and available at Code Climate these exclude entries should be removed.

* Replace `String#freeze` with `String#-@` manually if explicit frozen string objects are required

 - 'actionpack/test/controller/test_case_test.rb'
 - 'activemodel/test/cases/type/string_test.rb'
 - 'activesupport/lib/active_support/core_ext/string/strip.rb'
 - 'activesupport/test/core_ext/string_ext_test.rb'
 - 'railties/test/generators/actions_test.rb'

19 files changed, 42 insertions, 42 deletions

diff --git a/activerecord/lib/active_record/associations/builder/has_and_belongs_to_many.rb b/activerecord/lib/active_record/associations/builder/has_and_belongs_to_many.rb
index e3070e0472..0140aa15c8 100644
--- a/activerecord/lib/active_record/associations/builder/has_and_belongs_to_many.rb
+++ b/activerecord/lib/active_record/associations/builder/has_and_belongs_to_many.rb
@@ -63,7 +63,7 @@ module ActiveRecord::Associations::Builder # :nodoc:
 
     def middle_reflection(join_model)
       middle_name = [lhs_model.name.downcase.pluralize,
-                     association_name].join("_".freeze).gsub("::".freeze, "_".freeze).to_sym
+                     association_name].join("_").gsub("::", "_").to_sym
       middle_options = middle_options join_model
 
       HasMany.create_reflection(lhs_model,
diff --git a/activerecord/lib/active_record/attribute_methods.rb b/activerecord/lib/active_record/attribute_methods.rb
index 42eba27b2a..221ebea8ea 100644
--- a/activerecord/lib/active_record/attribute_methods.rb
+++ b/activerecord/lib/active_record/attribute_methods.rb
@@ -272,9 +272,9 @@ module ActiveRecord
 
       case name
       when :to_partial_path
-        name = "to_partial_path".freeze
+        name = "to_partial_path"
       when :to_model
-        name = "to_model".freeze
+        name = "to_model"
       else
         name = name.to_s
       end
diff --git a/activerecord/lib/active_record/attribute_methods/read.rb b/activerecord/lib/active_record/attribute_methods/read.rb
index 0f7bcba564..903fe86e04 100644
--- a/activerecord/lib/active_record/attribute_methods/read.rb
+++ b/activerecord/lib/active_record/attribute_methods/read.rb
@@ -27,7 +27,7 @@ module ActiveRecord
           # Making it frozen means that it doesn't get duped when used to
           # key the @attributes in read_attribute.
           def define_method_attribute(name)
-            safe_name = name.unpack1("h*".freeze)
+            safe_name = name.unpack1("h*")
             temp_method = "__temp__#{safe_name}"
 
             ActiveRecord::AttributeMethods::AttrNames.set_name_cache safe_name, name
@@ -59,7 +59,7 @@ module ActiveRecord
         end
 
         primary_key = self.class.primary_key
-        name = primary_key if name == "id".freeze && primary_key
+        name = primary_key if name == "id" && primary_key
         sync_with_transaction_state if name == primary_key
         _read_attribute(name, &block)
       end
diff --git a/activerecord/lib/active_record/attribute_methods/write.rb b/activerecord/lib/active_record/attribute_methods/write.rb
index c7521422bb..62743bc9d8 100644
--- a/activerecord/lib/active_record/attribute_methods/write.rb
+++ b/activerecord/lib/active_record/attribute_methods/write.rb
@@ -13,7 +13,7 @@ module ActiveRecord
         private
 
           def define_method_attribute=(name)
-            safe_name = name.unpack1("h*".freeze)
+            safe_name = name.unpack1("h*")
             ActiveRecord::AttributeMethods::AttrNames.set_name_cache safe_name, name
             sync_with_transaction_state = "sync_with_transaction_state" if name == primary_key
 
@@ -40,7 +40,7 @@ module ActiveRecord
         end
 
         primary_key = self.class.primary_key
-        name = primary_key if name == "id".freeze && primary_key
+        name = primary_key if name == "id" && primary_key
         sync_with_transaction_state if name == primary_key
         _write_attribute(name, value)
       end
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/quoting.rb b/activerecord/lib/active_record/connection_adapters/abstract/quoting.rb
index 98b1348135..07e86afe9a 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/quoting.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/quoting.rb
@@ -60,7 +60,7 @@ module ActiveRecord
       # Quotes a string, escaping any ' (single quote) and \ (backslash)
       # characters.
       def quote_string(s)
-        s.gsub('\\'.freeze, '\&\&'.freeze).gsub("'".freeze, "''".freeze) # ' (for ruby-mode)
+        s.gsub('\\', '\&\&').gsub("'", "''") # ' (for ruby-mode)
       end
 
       # Quotes the column name. Defaults to no quoting.
@@ -95,7 +95,7 @@ module ActiveRecord
       end
 
       def quoted_true
-        "TRUE".freeze
+        "TRUE"
       end
 
       def unquoted_true
@@ -103,7 +103,7 @@ module ActiveRecord
       end
 
       def quoted_false
-        "FALSE".freeze
+        "FALSE"
       end
 
       def unquoted_false
diff --git a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
index 79aafc956f..fa10f18cb7 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
@@ -65,7 +65,7 @@ module ActiveRecord
     # Most of the methods in the adapter are useful during migrations. Most
     # notably, the instance methods provided by SchemaStatements are very useful.
     class AbstractAdapter
-      ADAPTER_NAME = "Abstract".freeze
+      ADAPTER_NAME = "Abstract"
       include ActiveSupport::Callbacks
       define_callbacks :checkout, :checkin
 
diff --git a/activerecord/lib/active_record/connection_adapters/mysql/quoting.rb b/activerecord/lib/active_record/connection_adapters/mysql/quoting.rb
index be038403b8..75564a61d6 100644
--- a/activerecord/lib/active_record/connection_adapters/mysql/quoting.rb
+++ b/activerecord/lib/active_record/connection_adapters/mysql/quoting.rb
@@ -5,7 +5,7 @@ module ActiveRecord
     module MySQL
       module Quoting # :nodoc:
         def quote_column_name(name)
-          @quoted_column_names[name] ||= "`#{super.gsub('`', '``')}`".freeze
+          @quoted_column_names[name] ||= "`#{super.gsub('`', '``')}`"
         end
 
         def quote_table_name(name)
diff --git a/activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb b/activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb
index 10c8c8e8ab..9bdaa00336 100644
--- a/activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb
@@ -14,7 +14,7 @@ module ActiveRecord
       config[:flags] ||= 0
 
       if config[:flags].kind_of? Array
-        config[:flags].push "FOUND_ROWS".freeze
+        config[:flags].push "FOUND_ROWS"
       else
         config[:flags] |= Mysql2::Client::FOUND_ROWS
       end
@@ -32,7 +32,7 @@ module ActiveRecord
 
   module ConnectionAdapters
     class Mysql2Adapter < AbstractMysqlAdapter
-      ADAPTER_NAME = "Mysql2".freeze
+      ADAPTER_NAME = "Mysql2"
 
       include MySQL::DatabaseStatements
 
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/type_map_initializer.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/type_map_initializer.rb
index 79351bc3a4..83c21ba6ea 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/oid/type_map_initializer.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/type_map_initializer.rb
@@ -19,10 +19,10 @@ module ActiveRecord
           def run(records)
             nodes = records.reject { |row| @store.key? row["oid"].to_i }
             mapped = nodes.extract! { |row| @store.key? row["typname"] }
-            ranges = nodes.extract! { |row| row["typtype"] == "r".freeze }
-            enums = nodes.extract! { |row| row["typtype"] == "e".freeze }
-            domains = nodes.extract! { |row| row["typtype"] == "d".freeze }
-            arrays = nodes.extract! { |row| row["typinput"] == "array_in".freeze }
+            ranges = nodes.extract! { |row| row["typtype"] == "r" }
+            enums = nodes.extract! { |row| row["typtype"] == "e" }
+            domains = nodes.extract! { |row| row["typtype"] == "d" }
+            arrays = nodes.extract! { |row| row["typinput"] == "array_in" }
             composites = nodes.extract! { |row| row["typelem"].to_i != 0 }
 
             mapped.each     { |row| register_mapped_type(row)    }
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/type_metadata.rb b/activerecord/lib/active_record/connection_adapters/postgresql/type_metadata.rb
index ffd3be26b0..cd69d28139 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/type_metadata.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/type_metadata.rb
@@ -17,7 +17,7 @@ module ActiveRecord
       end
 
       def sql_type
-        super.gsub(/\[\]$/, "".freeze)
+        super.gsub(/\[\]$/, "")
       end
 
       def ==(other)
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
index 11593f71c9..bc6eb11572 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
@@ -78,7 +78,7 @@ module ActiveRecord
     # In addition, default connection parameters of libpq can be set per environment variables.
     # See https://www.postgresql.org/docs/current/static/libpq-envars.html .
     class PostgreSQLAdapter < AbstractAdapter
-      ADAPTER_NAME = "PostgreSQL".freeze
+      ADAPTER_NAME = "PostgreSQL"
 
       NATIVE_DATABASE_TYPES = {
         primary_key: "bigserial primary key",
@@ -448,7 +448,7 @@ module ActiveRecord
           end
         end
 
-        def get_oid_type(oid, fmod, column_name, sql_type = "".freeze)
+        def get_oid_type(oid, fmod, column_name, sql_type = "")
           if !type_map.key?(oid)
             load_additional_types([oid])
           end
@@ -537,13 +537,13 @@ module ActiveRecord
             # Quoted types
           when /\A[\(B]?'(.*)'.*::"?([\w. ]+)"?(?:\[\])?\z/m
             # The default 'now'::date is CURRENT_DATE
-            if $1 == "now".freeze && $2 == "date".freeze
+            if $1 == "now" && $2 == "date"
               nil
             else
-              $1.gsub("''".freeze, "'".freeze)
+              $1.gsub("''", "'")
             end
             # Boolean types
-          when "true".freeze, "false".freeze
+          when "true", "false"
             default
             # Numeric types
           when /\A\(?(-?\d+(\.\d*)?)\)?(::bigint)?\z/
@@ -655,7 +655,7 @@ module ActiveRecord
         #
         # Check here for more details:
         # https://git.postgresql.org/gitweb/?p=postgresql.git;a=blob;f=src/backend/utils/cache/plancache.c#l573
-        CACHED_PLAN_HEURISTIC = "cached plan must not change result type".freeze
+        CACHED_PLAN_HEURISTIC = "cached plan must not change result type"
         def is_cached_plan_failure?(e)
           pgerror = e.cause
           code = pgerror.result.result_error_field(PG::PG_DIAG_SQLSTATE)
diff --git a/activerecord/lib/active_record/connection_adapters/sqlite3/quoting.rb b/activerecord/lib/active_record/connection_adapters/sqlite3/quoting.rb
index abedf01f10..b2dcdb5373 100644
--- a/activerecord/lib/active_record/connection_adapters/sqlite3/quoting.rb
+++ b/activerecord/lib/active_record/connection_adapters/sqlite3/quoting.rb
@@ -13,7 +13,7 @@ module ActiveRecord
         end
 
         def quote_column_name(name)
-          @quoted_column_names[name] ||= %Q("#{super.gsub('"', '""')}").freeze
+          @quoted_column_names[name] ||= %Q("#{super.gsub('"', '""')}")
         end
 
         def quoted_time(value)
@@ -26,19 +26,19 @@ module ActiveRecord
         end
 
         def quoted_true
-          ActiveRecord::ConnectionAdapters::SQLite3Adapter.represent_boolean_as_integer ? "1".freeze : "'t'".freeze
+          ActiveRecord::ConnectionAdapters::SQLite3Adapter.represent_boolean_as_integer ? "1" : "'t'"
         end
 
         def unquoted_true
-          ActiveRecord::ConnectionAdapters::SQLite3Adapter.represent_boolean_as_integer ? 1 : "t".freeze
+          ActiveRecord::ConnectionAdapters::SQLite3Adapter.represent_boolean_as_integer ? 1 : "t"
         end
 
         def quoted_false
-          ActiveRecord::ConnectionAdapters::SQLite3Adapter.represent_boolean_as_integer ? "0".freeze : "'f'".freeze
+          ActiveRecord::ConnectionAdapters::SQLite3Adapter.represent_boolean_as_integer ? "0" : "'f'"
         end
 
         def unquoted_false
-          ActiveRecord::ConnectionAdapters::SQLite3Adapter.represent_boolean_as_integer ? 0 : "f".freeze
+          ActiveRecord::ConnectionAdapters::SQLite3Adapter.represent_boolean_as_integer ? 0 : "f"
         end
 
         private
diff --git a/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb b/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb
index baa0a29afd..81882f6cc1 100644
--- a/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb
@@ -56,7 +56,7 @@ module ActiveRecord
     #
     # * <tt>:database</tt> - Path to the database file.
     class SQLite3Adapter < AbstractAdapter
-      ADAPTER_NAME = "SQLite".freeze
+      ADAPTER_NAME = "SQLite"
 
       include SQLite3::Quoting
       include SQLite3::SchemaStatements
diff --git a/activerecord/lib/active_record/inheritance.rb b/activerecord/lib/active_record/inheritance.rb
index b25057acda..138fd1cf53 100644
--- a/activerecord/lib/active_record/inheritance.rb
+++ b/activerecord/lib/active_record/inheritance.rb
@@ -180,7 +180,7 @@ module ActiveRecord
         # Returns the class type of the record using the current module as a prefix. So descendants of
         # MyApp::Business::Account would appear as MyApp::Business::AccountSubclass.
         def compute_type(type_name)
-          if type_name.start_with?("::".freeze)
+          if type_name.start_with?("::")
             # If the type is prefixed with a scope operator then we assume that
             # the type_name is an absolute reference.
             ActiveSupport::Dependencies.constantize(type_name)
diff --git a/activerecord/lib/active_record/migration.rb b/activerecord/lib/active_record/migration.rb
index d712d4b3cf..6e5a610642 100644
--- a/activerecord/lib/active_record/migration.rb
+++ b/activerecord/lib/active_record/migration.rb
@@ -140,8 +140,8 @@ module ActiveRecord
   end
 
   class ConcurrentMigrationError < MigrationError #:nodoc:
-    DEFAULT_MESSAGE = "Cannot run migrations because another migration process is currently running.".freeze
-    RELEASE_LOCK_FAILED_MESSAGE = "Failed to release advisory lock".freeze
+    DEFAULT_MESSAGE = "Cannot run migrations because another migration process is currently running."
+    RELEASE_LOCK_FAILED_MESSAGE = "Failed to release advisory lock"
 
     def initialize(message = DEFAULT_MESSAGE)
       super
diff --git a/activerecord/lib/active_record/relation/delegation.rb b/activerecord/lib/active_record/relation/delegation.rb
index 488f71cdde..8f657840f5 100644
--- a/activerecord/lib/active_record/relation/delegation.rb
+++ b/activerecord/lib/active_record/relation/delegation.rb
@@ -17,7 +17,7 @@ module ActiveRecord
           delegate = Class.new(klass) {
             include ClassSpecificRelation
           }
-          mangled_name = klass.name.gsub("::".freeze, "_".freeze)
+          mangled_name = klass.name.gsub("::", "_")
           const_set mangled_name, delegate
           private_constant mangled_name
 
diff --git a/activerecord/lib/active_record/relation/predicate_builder.rb b/activerecord/lib/active_record/relation/predicate_builder.rb
index f734cd0ad8..b59ff912fe 100644
--- a/activerecord/lib/active_record/relation/predicate_builder.rb
+++ b/activerecord/lib/active_record/relation/predicate_builder.rb
@@ -27,7 +27,7 @@ module ActiveRecord
           key
         else
           key = key.to_s
-          key.split(".".freeze).first if key.include?(".".freeze)
+          key.split(".").first if key.include?(".")
         end
       end.compact
     end
@@ -115,11 +115,11 @@ module ActiveRecord
 
       def convert_dot_notation_to_hash(attributes)
         dot_notation = attributes.select do |k, v|
-          k.include?(".".freeze) && !v.is_a?(Hash)
+          k.include?(".") && !v.is_a?(Hash)
         end
 
         dot_notation.each_key do |key|
-          table_name, column_name = key.split(".".freeze)
+          table_name, column_name = key.split(".")
           value = attributes.delete(key)
           attributes[table_name] ||= {}
 
diff --git a/activerecord/lib/active_record/relation/query_methods.rb b/activerecord/lib/active_record/relation/query_methods.rb
index 56497e11cb..5170d38fa8 100644
--- a/activerecord/lib/active_record/relation/query_methods.rb
+++ b/activerecord/lib/active_record/relation/query_methods.rb
@@ -939,7 +939,7 @@ module ActiveRecord
         arel.having(having_clause.ast) unless having_clause.empty?
         if limit_value
           limit_attribute = ActiveModel::Attribute.with_cast_value(
-            "LIMIT".freeze,
+            "LIMIT",
             connection.sanitize_limit(limit_value),
             Type.default_value,
           )
@@ -947,7 +947,7 @@ module ActiveRecord
         end
         if offset_value
           offset_attribute = ActiveModel::Attribute.with_cast_value(
-            "OFFSET".freeze,
+            "OFFSET",
             offset_value.to_i,
             Type.default_value,
           )
diff --git a/activerecord/lib/active_record/tasks/postgresql_database_tasks.rb b/activerecord/lib/active_record/tasks/postgresql_database_tasks.rb
index d3c85b161e..8acb11f75f 100644
--- a/activerecord/lib/active_record/tasks/postgresql_database_tasks.rb
+++ b/activerecord/lib/active_record/tasks/postgresql_database_tasks.rb
@@ -6,8 +6,8 @@ module ActiveRecord
   module Tasks # :nodoc:
     class PostgreSQLDatabaseTasks # :nodoc:
       DEFAULT_ENCODING = ENV["CHARSET"] || "utf8"
-      ON_ERROR_STOP_1 = "ON_ERROR_STOP=1".freeze
-      SQL_COMMENT_BEGIN = "--".freeze
+      ON_ERROR_STOP_1 = "ON_ERROR_STOP=1"
+      SQL_COMMENT_BEGIN = "--"
 
       delegate :connection, :establish_connection, :clear_active_connections!,
         to: ActiveRecord::Base