Implement AR#inspect using ParamterFilter.

AR instance support `filter_parameters` since #33756.
Though Regex or Proc is valid as `filter_parameters`,
they are not supported as AR#inspect.

I also add :mask option and #filter_params to
`ActiveSupport::ParameterFilter#new` to implement this.

activerecord/CHANGELOG.md

@@ -138,13 +138,13 @@
     specify sensitive attributes to specific model.
 
     ```
-    Rails.application.config.filter_parameters += [:credit_card_number]
+    Rails.application.config.filter_parameters += [:credit_card_number, /phone/]
-    Account.last.inspect # => #<Account id: 123, name: "DHH", credit_card_number: [FILTERED] ...>
+    Account.last.inspect # => #<Account id: 123, name: "DHH", credit_card_number: [FILTERED], telephone_number: [FILTERED] ...>
     SecureAccount.filter_attributes += [:name]
     SecureAccount.last.inspect # => #<SecureAccount id: 42, name: [FILTERED], credit_card_number: [FILTERED] ...>
     ```
 
-    *Zhang Kang*
+    *Zhang Kang*, *Yoshiyuki Kinjo*
 
 *   Deprecate `column_name_length`, `table_name_length`, `columns_per_table`,
     `indexes_per_table`, `columns_per_multicolumn_index`, `sql_query_length`,

activerecord/lib/active_record/attribute_methods.rb

@@ -336,14 +336,7 @@ module ActiveRecord
     #   # => "[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]"
     def attribute_for_inspect(attr_name)
       value = read_attribute(attr_name)
-
+      format_for_inspect(value)
-      if value.is_a?(String) && value.length > 50
-        "#{value[0, 50]}...".inspect
-      elsif value.is_a?(Date) || value.is_a?(Time)
-        %("#{value.to_s(:db)}")
-      else
-        value.inspect
-      end
     end
 
     # Returns +true+ if the specified +attribute+ has been set by the user or by a
@@ -463,6 +456,16 @@ module ActiveRecord
         end
       end
 
+      def format_for_inspect(value)
+        if value.is_a?(String) && value.length > 50
+          "#{value[0, 50]}...".inspect
+        elsif value.is_a?(Date) || value.is_a?(Time)
+          %("#{value.to_s(:db)}")
+        else
+          value.inspect
+        end
+      end
+
       def readonly_attribute?(name)
         self.class.readonly_attributes.include?(name)
       end

activerecord/lib/active_record/core.rb

@@ -2,15 +2,13 @@
 
 require "active_support/core_ext/hash/indifferent_access"
 require "active_support/core_ext/string/filters"
+require "active_support/parameter_filter"
 require "concurrent/map"
-require "set"
 
 module ActiveRecord
   module Core
     extend ActiveSupport::Concern
 
-    FILTERED = "[FILTERED]" # :nodoc:
-
     included do
       ##
       # :singleton-method:
@@ -239,9 +237,7 @@ module ActiveRecord
       end
 
       # Specifies columns which shouldn't be exposed while calling +#inspect+.
-      def filter_attributes=(attributes_names)
+      attr_writer :filter_attributes
-        @filter_attributes = attributes_names.map(&:to_s).to_set
-      end
 
       # Returns a string like 'Post(id:integer, title:string, body:text)'
       def inspect # :nodoc:
@@ -514,11 +510,14 @@ module ActiveRecord
       inspection = if defined?(@attributes) && @attributes
         self.class.attribute_names.collect do |name|
           if has_attribute?(name)
-            if filter_attribute?(name)
+            attr = read_attribute(name)
-              "#{name}: #{ActiveRecord::Core::FILTERED}"
+            value = if attr.nil?
+              attr.inspect
             else
-              "#{name}: #{attribute_for_inspect(name)}"
+              attr = format_for_inspect(attr)
+              inspection_filter.filter_param(name, attr)
             end
+            "#{name}: #{value}"
           end
         end.compact.join(", ")
       else
@@ -534,18 +533,16 @@ module ActiveRecord
       return super if custom_inspect_method_defined?
       pp.object_address_group(self) do
         if defined?(@attributes) && @attributes
-          column_names = self.class.column_names.select { |name| has_attribute?(name) || new_record? }
+          attr_names = self.class.attribute_names.select { |name| has_attribute?(name) }
-          pp.seplist(column_names, proc { pp.text "," }) do |column_name|
+          pp.seplist(attr_names, proc { pp.text "," }) do |attr_name|
             pp.breakable " "
             pp.group(1) do
-              pp.text column_name
+              pp.text attr_name
               pp.text ":"
               pp.breakable
-              if filter_attribute?(column_name)
+              value = read_attribute(attr_name)
-                pp.text ActiveRecord::Core::FILTERED
+              value = inspection_filter.filter_param(attr_name, value) unless value.nil?
-              else
+              pp.pp value
-                pp.pp read_attribute(column_name)
-              end
             end
           end
         else
@@ -597,8 +594,14 @@ module ActiveRecord
         self.class.instance_method(:inspect).owner != ActiveRecord::Base.instance_method(:inspect).owner
       end
 
-      def filter_attribute?(attribute_name)
+      def inspection_filter
-        self.class.filter_attributes.include?(attribute_name) && !read_attribute(attribute_name).nil?
+        @inspection_filter ||= begin
+          mask = DelegateClass(::String).new(ActiveSupport::ParameterFilter::FILTERED)
+          def mask.pretty_print(pp)
+            pp.text __getobj__
+          end
+          ActiveSupport::ParameterFilter.new(self.class.filter_attributes, mask: mask)
+        end
       end
   end
 end

activerecord/test/cases/filter_attributes_test.rb

@@ -4,6 +4,7 @@ require "cases/helper"
 require "models/admin"
 require "models/admin/user"
 require "models/admin/account"
+require "models/user"
 require "pp"
 
 class FilterAttributesTest < ActiveRecord::TestCase
@@ -30,6 +31,32 @@ class FilterAttributesTest < ActiveRecord::TestCase
     end
   end
 
+  test "string filter_attributes perform pertial match" do
+    ActiveRecord::Base.filter_attributes = ["n"]
+    Admin::Account.all.each do |account|
+      assert_includes account.inspect, "name: [FILTERED]"
+      assert_equal 1, account.inspect.scan("[FILTERED]").length
+    end
+  end
+
+  test "regex filter_attributes are accepted" do
+    ActiveRecord::Base.filter_attributes = [/\An\z/]
+    account = Admin::Account.find_by(name: "37signals")
+    assert_includes account.inspect, 'name: "37signals"'
+    assert_equal 0, account.inspect.scan("[FILTERED]").length
+
+    ActiveRecord::Base.filter_attributes = [/\An/]
+    account = Admin::Account.find_by(name: "37signals")
+    assert_includes account.reload.inspect, "name: [FILTERED]"
+    assert_equal 1, account.inspect.scan("[FILTERED]").length
+  end
+
+  test "proc filter_attributes are accepted" do
+    ActiveRecord::Base.filter_attributes = [ lambda { |key, value| value.reverse! if key == "name" } ]
+    account = Admin::Account.find_by(name: "37signals")
+    assert_includes account.inspect, 'name: "slangis73"'
+  end
+
   test "filter_attributes could be overwritten by models" do
     Admin::Account.all.each do |account|
       assert_includes account.inspect, "name: [FILTERED]"
@@ -37,7 +64,6 @@ class FilterAttributesTest < ActiveRecord::TestCase
     end
 
     begin
-      previous_account_filter_attributes = Admin::Account.filter_attributes
       Admin::Account.filter_attributes = []
 
       # Above changes should not impact other models
@@ -51,7 +77,7 @@ class FilterAttributesTest < ActiveRecord::TestCase
         assert_equal 0, account.inspect.scan("[FILTERED]").length
       end
     ensure
-      Admin::Account.filter_attributes = previous_account_filter_attributes
+      Admin::Account.remove_instance_variable(:@filter_attributes)
     end
   end
 
@@ -63,6 +89,18 @@ class FilterAttributesTest < ActiveRecord::TestCase
     assert_equal 0, account.inspect.scan("[FILTERED]").length
   end
 
+  test "filter_attributes should handle [FILTERED] value properly" do
+    begin
+      User.filter_attributes = ["auth"]
+      user = User.new(token: "[FILTERED]", auth_token: "[FILTERED]")
+
+      assert_includes user.inspect, "auth_token: [FILTERED]"
+      assert_includes user.inspect, 'token: "[FILTERED]"'
+    ensure
+      User.remove_instance_variable(:@filter_attributes)
+    end
+  end
+
   test "filter_attributes on pretty_print" do
     user = admin_users(:david)
     actual = "".dup
@@ -81,4 +119,18 @@ class FilterAttributesTest < ActiveRecord::TestCase
     assert_not_includes actual, "name: [FILTERED]"
     assert_equal 0, actual.scan("[FILTERED]").length
   end
+
+  test "filter_attributes on pretty_print should handle [FILTERED] value properly" do
+    begin
+      User.filter_attributes = ["auth"]
+      user = User.new(token: "[FILTERED]", auth_token: "[FILTERED]")
+      actual = "".dup
+      PP.pp(user, StringIO.new(actual))
+
+      assert_includes actual, "auth_token: [FILTERED]"
+      assert_includes actual, 'token: "[FILTERED]"'
+    ensure
+      User.remove_instance_variable(:@filter_attributes)
+    end
+  end
 end

activesupport/lib/active_support/parameter_filter.rb

@@ -28,22 +28,36 @@ module ActiveSupport
   class ParameterFilter
     FILTERED = "[FILTERED]" # :nodoc:
 
-    def initialize(filters = [])
+    # Create instance with given filters. Supported type of filters are +String+, +Regexp+, and +Proc+.
+    # Other types of filters are treated as +String+ using +to_s+.
+    # For +Proc+ filters, key, value, and optional original hash is passed to block arguments.
+    #
+    # ==== Options
+    #
+    # * <tt>:mask</tt> - A replaced object when filtered. Defaults to +"[FILTERED]"+
+    def initialize(filters = [], mask: FILTERED)
       @filters = filters
+      @mask = mask
     end
 
+    # Mask value of +params+ if key matches one of filters.
     def filter(params)
       compiled_filter.call(params)
     end
 
+    # Returns filtered value for given key. For +Proc+ filters, third block argument is not populated.
+    def filter_param(key, value)
+      @filters.empty? ? value : compiled_filter.value_for_key(key, value)
+    end
+
   private
 
     def compiled_filter
-      @compiled_filter ||= CompiledFilter.compile(@filters)
+      @compiled_filter ||= CompiledFilter.compile(@filters, mask: @mask)
     end
 
     class CompiledFilter # :nodoc:
-      def self.compile(filters)
+      def self.compile(filters, mask:)
         return lambda { |params| params.dup } if filters.empty?
 
         strings, regexps, blocks = [], [], []
@@ -65,26 +79,34 @@ module ActiveSupport
         regexps << Regexp.new(strings.join("|"), true) unless strings.empty?
         deep_regexps << Regexp.new(deep_strings.join("|"), true) unless deep_strings.empty?
 
-        new regexps, deep_regexps, blocks
+        new regexps, deep_regexps, blocks, mask: mask
       end
 
       attr_reader :regexps, :deep_regexps, :blocks
 
-      def initialize(regexps, deep_regexps, blocks)
+      def initialize(regexps, deep_regexps, blocks, mask:)
         @regexps = regexps
         @deep_regexps = deep_regexps.any? ? deep_regexps : nil
         @blocks = blocks
+        @mask = mask
       end
 
       def call(params, parents = [], original_params = params)
         filtered_params = params.class.new
 
         params.each do |key, value|
+          filtered_params[key] = value_for_key(key, value, parents, original_params)
+        end
+
+        filtered_params
+      end
+
+      def value_for_key(key, value, parents = [], original_params = nil)
         parents.push(key) if deep_regexps
-          if regexps.any? { |r| key =~ r }
+        if regexps.any? { |r| r.match?(key) }
-            value = FILTERED
+          value = @mask
-          elsif deep_regexps && (joined = parents.join(".")) && deep_regexps.any? { |r| joined =~ r }
+        elsif deep_regexps && (joined = parents.join(".")) && deep_regexps.any? { |r| r.match?(joined) }
-            value = FILTERED
+          value = @mask
         elsif value.is_a?(Hash)
           value = call(value, parents, original_params)
         elsif value.is_a?(Array)
@@ -95,11 +117,7 @@ module ActiveSupport
           blocks.each { |b| b.arity == 2 ? b.call(key, value) : b.call(key, value, original_params) }
         end
         parents.pop if deep_regexps
-
+        value
-          filtered_params[key] = value
-        end
-
-        filtered_params
       end
     end
   end

activesupport/test/parameter_filter_test.rb

@@ -36,6 +36,51 @@ class ParameterFilterTest < ActiveSupport::TestCase
     end
   end
 
+  test "filter should return mask option when value is filtered" do
+    mask = Object.new.freeze
+    test_hashes = [
+    [{ "foo" => "bar" }, { "foo" => "bar" }, %w'food'],
+    [{ "foo" => "bar" }, { "foo" => mask }, %w'foo'],
+    [{ "foo" => "bar", "bar" => "foo" }, { "foo" => mask, "bar" => "foo" }, %w'foo baz'],
+    [{ "foo" => "bar", "baz" => "foo" }, { "foo" => mask, "baz" => mask }, %w'foo baz'],
+    [{ "bar" => { "foo" => "bar", "bar" => "foo" } }, { "bar" => { "foo" => mask, "bar" => "foo" } }, %w'fo'],
+    [{ "foo" => { "foo" => "bar", "bar" => "foo" } }, { "foo" => mask }, %w'f banana'],
+    [{ "deep" => { "cc" => { "code" => "bar", "bar" => "foo" }, "ss" => { "code" => "bar" } } }, { "deep" => { "cc" => { "code" => mask, "bar" => "foo" }, "ss" => { "code" => "bar" } } }, %w'deep.cc.code'],
+    [{ "baz" => [{ "foo" => "baz" }, "1"] }, { "baz" => [{ "foo" => mask }, "1"] }, [/foo/]]]
+
+    test_hashes.each do |before_filter, after_filter, filter_words|
+      parameter_filter = ActiveSupport::ParameterFilter.new(filter_words, mask: mask)
+      assert_equal after_filter, parameter_filter.filter(before_filter)
+
+      filter_words << "blah"
+      filter_words << lambda { |key, value|
+        value.reverse! if key =~ /bargain/
+      }
+      filter_words << lambda { |key, value, original_params|
+        value.replace("world!") if original_params["barg"]["blah"] == "bar" && key == "hello"
+      }
+
+      parameter_filter = ActiveSupport::ParameterFilter.new(filter_words, mask: mask)
+      before_filter["barg"] = { :bargain => "gain", "blah" => "bar", "bar" => { "bargain" => { "blah" => "foo", "hello" => "world" } } }
+      after_filter["barg"]  = { :bargain => "niag", "blah" => mask, "bar" => { "bargain" => { "blah" => mask, "hello" => "world!" } } }
+
+      assert_equal after_filter, parameter_filter.filter(before_filter)
+    end
+  end
+
+  test "filter_param" do
+    parameter_filter = ActiveSupport::ParameterFilter.new(["foo", /bar/])
+    assert_equal "[FILTERED]", parameter_filter.filter_param("food", "secret vlaue")
+    assert_equal "[FILTERED]", parameter_filter.filter_param("baz.foo", "secret vlaue")
+    assert_equal "[FILTERED]", parameter_filter.filter_param("barbar", "secret vlaue")
+    assert_equal "non secret value", parameter_filter.filter_param("baz", "non secret value")
+  end
+
+  test "filter_param can work with empty filters" do
+    parameter_filter = ActiveSupport::ParameterFilter.new
+    assert_equal "bar", parameter_filter.filter_param("foo", "bar")
+  end
+
   test "parameter filter should maintain hash with indifferent access" do
     test_hashes = [
       [{ "foo" => "bar" }.with_indifferent_access, ["blah"]],
@@ -48,4 +93,13 @@ class ParameterFilterTest < ActiveSupport::TestCase
                          parameter_filter.filter(before_filter)
     end
   end
+
+  test "filter_param should return mask option when value is filtered" do
+    mask = Object.new.freeze
+    parameter_filter = ActiveSupport::ParameterFilter.new(["foo", /bar/], mask: mask)
+    assert_equal mask, parameter_filter.filter_param("food", "secret vlaue")
+    assert_equal mask, parameter_filter.filter_param("baz.foo", "secret vlaue")
+    assert_equal mask, parameter_filter.filter_param("barbar", "secret vlaue")
+    assert_equal "non secret value", parameter_filter.filter_param("baz", "non secret value")
+  end
 end

railties/test/application/configuration_test.rb

@@ -2109,7 +2109,7 @@ module ApplicationTests
       RUBY
       app "development"
       assert_equal [ :password, :credit_card_number ], Rails.application.config.filter_parameters
-      assert_equal [ "password", "credit_card_number" ].to_set, ActiveRecord::Base.filter_attributes
+      assert_equal [ :password, :credit_card_number ], ActiveRecord::Base.filter_attributes
     end
 
     test "ActiveStorage.routes_prefix can be configured via config.active_storage.routes_prefix" do