Merge pull request #37940 from cpruitt/activesupport-disallowed-depre…

…cations

Introduce ActiveSupport Disallowed Deprecations

activesupport/lib/active_support/deprecation.rb

@@ -17,6 +17,7 @@ class Deprecation
     require "active_support/deprecation/instance_delegator"
     require "active_support/deprecation/behaviors"
     require "active_support/deprecation/reporting"
+    require "active_support/deprecation/disallowed"
     require "active_support/deprecation/constant_accessor"
     require "active_support/deprecation/method_wrappers"
     require "active_support/deprecation/proxy_wrappers"
@@ -27,6 +28,7 @@ class Deprecation
     include InstanceDelegator
     include Behavior
     include Reporting
+    include Disallowed
     include MethodWrapper
 
     # The version number in which the deprecated behavior will be removed, by default.
@@ -43,6 +45,7 @@ def initialize(deprecation_horizon = "6.2", gem_name = "Rails")
       self.silenced = false
       self.debug = false
       @silenced_thread = Concurrent::ThreadLocalVar.new(false)
+      @explicitly_allowed_warnings = Concurrent::ThreadLocalVar.new(nil)
     end
   end
 end

activesupport/lib/active_support/deprecation/behaviors.rb

@@ -67,6 +67,11 @@ def behavior
         @behavior ||= [DEFAULT_BEHAVIORS[:stderr]]
       end
 
+      # Returns the current behavior for disallowed deprecations or if one isn't set, defaults to +:raise+.
+      def disallowed_behavior
+        @disallowed_behavior ||= [DEFAULT_BEHAVIORS[:raise]]
+      end
+
       # Sets the behavior to the specified value. Can be a single value, array,
       # or an object that responds to +call+.
       #
@@ -92,6 +97,14 @@ def behavior=(behavior)
         @behavior = Array(behavior).map { |b| DEFAULT_BEHAVIORS[b] || arity_coerce(b) }
       end
 
+      # Sets the behavior for disallowed deprecations (those configured by
+      # ActiveSupport::Deprecation.disallowed_warnings=) to the specified
+      # value. As with +behavior=+, this can be a single value, array, or an
+      # object that responds to +call+.
+      def disallowed_behavior=(behavior)
+        @disallowed_behavior = Array(behavior).map { |b| DEFAULT_BEHAVIORS[b] || arity_coerce(b) }
+      end
+
       private
         def arity_coerce(behavior)
           unless behavior.respond_to?(:call)

activesupport/lib/active_support/deprecation/disallowed.rb

@@ -0,0 +1,56 @@
+# frozen_string_literal: true
+
+module ActiveSupport
+  class Deprecation
+    module Disallowed
+      # Sets the criteria used to identify deprecation messages which should be
+      # disallowed. Can be an array containing strings, symbols, or regular
+      # expressions. (Symbols are treated as strings). These are compared against
+      # the text of the generated deprecation warning.
+      #
+      # Additionally the scalar symbol +:all+ may be used to treat all
+      # deprecations as disallowed.
+      #
+      # Deprecations matching a substring or regular expression will be handled
+      # using the configured +ActiveSupport::Deprecation.disallowed_behavior+
+      # rather than +ActiveSupport::Deprecation.behavior+
+      attr_writer :disallowed_warnings
+
+      # Returns the configured criteria used to identify deprecation messages
+      # which should be treated as disallowed.
+      def disallowed_warnings
+        @disallowed_warnings ||= []
+      end
+
+      private
+        def deprecation_disallowed?(message)
+          disallowed = ActiveSupport::Deprecation.disallowed_warnings
+          return false if explicitly_allowed?(message)
+          return true if disallowed == :all
+          disallowed.any? do |rule|
+            case rule
+            when String, Symbol
+              message.include?(rule.to_s)
+            when Regexp
+              rule.match(message)
+            end
+          end
+        end
+
+        def explicitly_allowed?(message)
+          allowances = @explicitly_allowed_warnings.value
+          return false unless allowances
+          return true if allowances == :all
+          allowances = [allowances] unless allowances.kind_of?(Array)
+          allowances.any? do |rule|
+            case rule
+            when String, Symbol
+              message.include?(rule.to_s)
+            when Regexp
+              rule.match(message)
+            end
+          end
+        end
+    end
+  end
+end

activesupport/lib/active_support/deprecation/reporting.rb

@@ -20,7 +20,11 @@ def warn(message = nil, callstack = nil)
 
         callstack ||= caller_locations(2)
         deprecation_message(callstack, message).tap do |m|
-          behavior.each { |b| b.call(m, callstack, deprecation_horizon, gem_name) }
+          if deprecation_disallowed?(message)
+            disallowed_behavior.each { |b| b.call(m, callstack, deprecation_horizon, gem_name) }
+          else
+            behavior.each { |b| b.call(m, callstack, deprecation_horizon, gem_name) }
+          end
         end
       end
 
@@ -37,6 +41,44 @@ def silence(&block)
         @silenced_thread.bind(true, &block)
       end
 
+      # Allow previously disallowed deprecation warnings within the block.
+      # <tt>allowed_warnings<tt> can be an array containing strings, symbols, or regular
+      # expressions. (Symbols are treated as strings). These are compared against
+      # the text of deprecation warning messages generated within the block.
+      # Matching warnings will be exempt from the rules set by
+      # +ActiveSupport::Deprecation.disallowed_warnings+
+      #
+      # The optional <tt>if:</tt> argument accepts a truthy/falsy value or an object that
+      # responds to <tt>.call</tt>. If truthy, then matching warnings will be allowed.
+      # If falsey then the method yields to the block without allowing the warning.
+      #
+      #   ActiveSupport::Deprecation.disallowed_behavior = :raise
+      #   ActiveSupport::Deprecation.disallowed_warnings = [
+      #     "something broke"
+      #   ]
+      #
+      #   ActiveSupport::Deprecation.warn('something broke!')
+      #   # => ActiveSupport::DeprecationException
+      #
+      #   ActiveSupport::Deprecation.allow ['something broke'] do
+      #     ActiveSupport::Deprecation.warn('something broke!')
+      #   end
+      #   # => nil
+      #
+      #   ActiveSupport::Deprecation.allow ['something broke'], if: Rails.env.production? do
+      #     ActiveSupport::Deprecation.warn('something broke!')
+      #   end
+      #   # => ActiveSupport::DeprecationException for dev/test, nil for production
+      def allow(allowed_warnings = :all, if: true, &block)
+        conditional = binding.local_variable_get(:if)
+        conditional = conditional.call if conditional.respond_to?(:call)
+        if conditional
+          @explicitly_allowed_warnings.bind(allowed_warnings, &block)
+        else
+          yield
+        end
+      end
+
       def silenced
         @silenced || @silenced_thread.value
       end

activesupport/lib/active_support/railtie.rb

@@ -28,6 +28,14 @@ class Railtie < Rails::Railtie # :nodoc:
       if deprecation = app.config.active_support.deprecation
         ActiveSupport::Deprecation.behavior = deprecation
       end
+
+      if disallowed_deprecation = app.config.active_support.disallowed_deprecation
+        ActiveSupport::Deprecation.disallowed_behavior = disallowed_deprecation
+      end
+
+      if disallowed_warnings = app.config.active_support.disallowed_deprecation_warnings
+        ActiveSupport::Deprecation.disallowed_warnings = disallowed_warnings
+      end
     end
 
     # Sets the default value for Time.zone