diff --git a/.github/workflows/lint.yml b/.github/workflows/lint.yml
index 9a537186dbd..b01d005cc19 100644
--- a/.github/workflows/lint.yml
+++ b/.github/workflows/lint.yml
@@ -27,6 +27,7 @@ jobs:
       uses: actions/setup-python@v3
       with:
         python-version: "3.10"
+
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
@@ -34,19 +35,8 @@ jobs:
     - name: Check spelling with codespell
       run: codespell --ignore-words=codespell.txt --skip="./vendor/bundle,./actionview/test/ujs/public/vendor/qunit.js,./actiontext/app/assets/javascripts/trix.js,./yarn.lock" || exit 1
 
-    - uses: actions/checkout@v4
-      with:
-        repository: skipkayhil/rails-bin
-        ref: 748f4673a5fe5686b5859e89f814166280e51781
-    - uses: ruby/setup-ruby@v1
-      with:
-        ruby-version: 3.2
-        bundler-cache: true
-    - uses: actions/checkout@v4
-      with:
-        path: rails
-    - run: bin/check-changelogs ./rails
-    - run: bin/check-config-docs ./rails
+    - run: tools/railspect changelogs .
+    - run: tools/railspect configuration .
 
     - uses: zzak/action-discord@v8
       continue-on-error: true
diff --git a/.github/workflows/rail_inspector.yml b/.github/workflows/rail_inspector.yml
new file mode 100644
index 00000000000..ac7dd091faf
--- /dev/null
+++ b/.github/workflows/rail_inspector.yml
@@ -0,0 +1,24 @@
+name: Rail Inspector
+
+on:
+  pull_request:
+    paths:
+    - "tools/rail_inspector/**"
+  push:
+    paths:
+    - "tools/rail_inspector/**"
+
+permissions:
+  contents: read
+
+jobs:
+  rail_inspector:
+    name: rail_inspector tests
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: 3.2
+          bundler-cache: true
+      - run: cd tools/rail_inspector && bundle exec rake
diff --git a/.rubocop.yml b/.rubocop.yml
index 91fff120d77..08c8e60fe10 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -19,6 +19,7 @@ AllCops:
     - 'actionmailbox/test/dummy/**/*'
     - 'activestorage/test/dummy/**/*'
     - 'actiontext/test/dummy/**/*'
+    - 'tools/rail_inspector/test/fixtures/*'
     - '**/node_modules/**/*'
     - '**/CHANGELOG.md'
     - '**/2_*_release_notes.md'
diff --git a/Gemfile b/Gemfile
index d9de12e1e38..b208b3e9b18 100644
--- a/Gemfile
+++ b/Gemfile
@@ -45,6 +45,10 @@ gem "json", ">= 2.0.0"
 # Workaround until Ruby ships with cgi version 0.3.6 or higher.
 gem "cgi", ">= 0.3.6", require: false
 
+group :lint do
+  gem "syntax_tree", "6.1.1", require: false
+end
+
 group :rubocop do
   gem "rubocop", ">= 1.25.1", require: false
   gem "rubocop-minitest", require: false
diff --git a/Gemfile.lock b/Gemfile.lock
index 83adc65d13e..ef4e7a5f61d 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -369,6 +369,7 @@ GEM
       ast (~> 2.4.1)
     path_expander (1.1.1)
     pg (1.5.3)
+    prettier_print (1.2.1)
     propshaft (0.6.4)
       actionpack (>= 7.0.0)
       activesupport (>= 7.0.0)
@@ -513,6 +514,8 @@ GEM
     stringio (3.0.7)
     sucker_punch (3.1.0)
       concurrent-ruby (~> 1.0)
+    syntax_tree (6.1.1)
+      prettier_print (>= 1.2.0)
     tailwindcss-rails (2.0.21)
       railties (>= 6.0.0)
     tailwindcss-rails (2.0.21-x86_64-darwin)
@@ -631,6 +634,7 @@ DEPENDENCIES
   stackprof
   stimulus-rails
   sucker_punch
+  syntax_tree (= 6.1.1)
   tailwindcss-rails
   terser (>= 1.1.4)
   trilogy (>= 2.5.0)
diff --git a/tools/README.md b/tools/README.md
index f133b27128d..2dbe65d14a3 100644
--- a/tools/README.md
+++ b/tools/README.md
@@ -5,6 +5,7 @@ They aren't used by Rails apps directly.
 
   * `console` drops you in irb and loads local Rails repos
   * `profile` profiles `Kernel#require` to help reduce startup time
+  * `railspect` provides commands to run internal linters
   * `line_statistics` provides CodeTools module and LineStatistics class to count lines
   * `test` is loaded by every major component of Rails to simplify testing, for example:
     `cd ./actioncable; bin/test ./path/to/actioncable_test_with_line_number.rb:5`
diff --git a/tools/rail_inspector/LICENSE b/tools/rail_inspector/LICENSE
new file mode 100644
index 00000000000..d39c8b0f421
--- /dev/null
+++ b/tools/rail_inspector/LICENSE
@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) Hartley McGuire
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/tools/rail_inspector/Rakefile b/tools/rail_inspector/Rakefile
new file mode 100644
index 00000000000..478656f61ed
--- /dev/null
+++ b/tools/rail_inspector/Rakefile
@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+require "bundler/gem_tasks"
+require "minitest/test_task"
+require "rubocop/rake_task"
+
+Minitest::TestTask.create
+
+RuboCop::RakeTask.new
+
+task default: [:test, :rubocop]
diff --git a/tools/rail_inspector/bin/console b/tools/rail_inspector/bin/console
new file mode 100755
index 00000000000..534eaa8d0b5
--- /dev/null
+++ b/tools/rail_inspector/bin/console
@@ -0,0 +1,15 @@
+#!/usr/bin/env ruby
+# frozen_string_literal: true
+
+require "bundler/setup"
+require_relative "../lib/rail_inspector"
+
+# You can add fixtures and/or initialization code here to make experimenting
+# with your gem easier. You can also use a different console, if you like.
+
+# (If you use this, don't forget to add pry to your Gemfile!)
+# require "pry"
+# Pry.start
+
+require "irb"
+IRB.start(__FILE__)
diff --git a/tools/rail_inspector/lib/rail_inspector.rb b/tools/rail_inspector/lib/rail_inspector.rb
new file mode 100644
index 00000000000..98dd03fe925
--- /dev/null
+++ b/tools/rail_inspector/lib/rail_inspector.rb
@@ -0,0 +1,28 @@
+# frozen_string_literal: true
+
+require_relative "rail_inspector/version"
+
+# MIT License
+#
+# Copyright (c) Hartley McGuire
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in all
+# copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+
+module RailInspector
+end
diff --git a/tools/rail_inspector/lib/rail_inspector/changelog.rb b/tools/rail_inspector/lib/rail_inspector/changelog.rb
new file mode 100644
index 00000000000..aace936efa7
--- /dev/null
+++ b/tools/rail_inspector/lib/rail_inspector/changelog.rb
@@ -0,0 +1,257 @@
+# frozen_string_literal: true
+
+require "pathname"
+require "strscan"
+
+module RailInspector
+  class Changelog
+    class Offense
+      attr_reader :line, :line_number, :range, :message
+
+      def initialize(line, line_number, range, message)
+        @line = line
+        @line_number = line_number
+        @range = range
+        @message = message
+      end
+    end
+
+    class Entry
+      attr_reader :lines, :offenses
+
+      def initialize(lines, starting_line)
+        @lines = lines
+        @starting_line = starting_line
+
+        @offenses = []
+
+        validate_authors
+        validate_leading_whitespace
+        validate_trailing_whitespace
+      end
+
+      private
+        def header
+          lines.first
+        end
+
+        def validate_authors
+          authors =
+            lines.reverse.find { |line| line.match?(/\*[^\d\s]+(\s[^\d\s]+)*\*/) }
+
+          return if authors
+
+          add_offense(
+            header,
+            line_in_file(0),
+            1..header.length,
+            "CHANGELOG entry is missing authors."
+          )
+        end
+
+        def validate_leading_whitespace
+          unless header.match?(/\* {3}\S/)
+            add_offense(
+              header,
+              line_in_file(0),
+              1..4,
+              "CHANGELOG header must start with '*' and 3 spaces"
+            )
+          end
+
+          lines.each_with_index do |line, i|
+            next if i == 0
+            next if line.strip.empty?
+            next if line.start_with?(" " * 4)
+
+            add_offense(
+              line,
+              line_in_file(i),
+              1..4,
+              "CHANGELOG line must be indented 4 spaces"
+            )
+          end
+        end
+
+        def validate_trailing_whitespace
+          lines.each_with_index do |line, i|
+            next unless line.end_with?(" ", "\t")
+
+            add_offense(
+              line,
+              line_in_file(i),
+              (line.rstrip.length + 1)..line.length,
+              "Trailing whitespace detected."
+            )
+          end
+        end
+
+      private
+        def add_offense(...)
+          @offenses << Offense.new(...)
+        end
+
+        def line_in_file(line_in_entry)
+          @starting_line + line_in_entry
+        end
+    end
+
+    class Parser
+      def self.call(file)
+        new(file).parse
+      end
+
+      def self.to_proc
+        method(:call).to_proc
+      end
+
+      def initialize(file)
+        @buffer = StringScanner.new(file)
+        @lines = []
+        @current_line = 1
+
+        @entries = []
+      end
+
+      def parse
+        until @buffer.eos?
+          if peek_footer?
+            pop_entry
+            next parse_footer
+          end
+
+          pop_entry if peek_probably_header?
+
+          parse_line
+        end
+
+        @entries
+      end
+
+      private
+        def parse_line
+          @current_line += 1
+          @lines << @buffer.scan_until(/\n/)[0...-1]
+        end
+
+        FOOTER_TEXT = "Please check"
+
+        def parse_footer
+          @buffer.scan(
+            /#{FOOTER_TEXT} \[\d-\d-stable\]\(.*\) for previous changes\.\n/o
+          )
+        end
+
+        def peek_probably_header?
+          return false unless @buffer.peek(1) == "*"
+
+          maybe_header = @buffer.check_until(/\n/).strip
+
+          # If there are an odd number of *, then the line is almost certainly a
+          # header since bolding requires pairs.
+          return true unless maybe_header.count("*").even?
+
+          !maybe_header.end_with?("*")
+        end
+
+        def peek_footer?
+          @buffer.peek(FOOTER_TEXT.length) == FOOTER_TEXT
+        end
+
+        def pop_entry
+          # Ensure we don't pop an entry if we only see newlines and the footer
+          return unless @lines.any? { |line| line.match?(/\S/) }
+
+          @entries << Changelog::Entry.new(@lines, @current_line - @lines.length)
+          @lines = []
+        end
+    end
+
+    class Formatter
+      def initialize
+        @changelog_count = 0
+        @offense_count = 0
+      end
+
+      def to_proc
+        method(:call).to_proc
+      end
+
+      def call(changelog)
+        @changelog_count += 1
+
+        changelog.offenses.each { |o| process_offense(changelog, o) }
+      end
+
+      def finish
+        puts "#{@changelog_count} changelogs inspected, #{@offense_count} offense#{"s" unless @offense_count == 1} detected"
+      end
+
+      private
+        def process_offense(file, offense)
+          @offense_count += 1
+
+          puts "#{file.path}:#{offense.line_number} #{offense.message}"
+          puts offense.line
+          puts ("^" * offense.range.count).rjust(offense.range.end)
+        end
+    end
+
+    class Runner
+      attr_reader :formatter, :rails_path
+
+      def initialize(rails_path)
+        @formatter = Formatter.new
+        @rails_path = Pathname.new(rails_path)
+      end
+
+      def call
+        invalid_changelogs =
+          changelogs.reject do |changelog|
+            output = changelog.valid? ? "." : "E"
+            $stdout.write(output)
+
+            changelog.valid?
+          end
+
+        puts "\n\n"
+        puts "Offenses:\n\n" unless invalid_changelogs.empty?
+
+        changelogs.each(&formatter)
+        formatter.finish
+
+        invalid_changelogs.empty?
+      end
+
+      private
+        def changelogs
+          changelog_paths.map { |path| Changelog.new(path, File.read(path)) }
+        end
+
+        def changelog_paths
+          Dir[rails_path.join("*/CHANGELOG.md")]
+        end
+    end
+
+    attr_reader :path, :content, :entries
+
+    def initialize(path, content)
+      @path = path
+      @content = content
+      @entries = parser.parse
+    end
+
+    def valid?
+      offenses.empty?
+    end
+
+    def offenses
+      @offenses ||= entries.flat_map(&:offenses)
+    end
+
+    private
+      def parser
+        @parser ||= Parser.new(content)
+      end
+  end
+end
diff --git a/tools/rail_inspector/lib/rail_inspector/cli.rb b/tools/rail_inspector/lib/rail_inspector/cli.rb
new file mode 100644
index 00000000000..1823f81a916
--- /dev/null
+++ b/tools/rail_inspector/lib/rail_inspector/cli.rb
@@ -0,0 +1,34 @@
+# frozen_string_literal: true
+
+require "thor"
+
+module RailInspector
+  class Cli < Thor
+    class << self
+      def exit_on_failure?
+        true
+      end
+    end
+
+    desc "changelogs RAILS_PATH", "Check CHANGELOG files for common issues"
+    def changelogs(rails_path)
+      require_relative "./changelog"
+
+      exit Changelog::Runner.new(rails_path).call
+    end
+
+    desc "configuration RAILS_PATH", "Check various Configuration issues"
+    option :autocorrect, type: :boolean, aliases: :a
+    def configuration(rails_path)
+      require_relative "./configuring"
+
+      checker = Configuring.new(rails_path)
+      checker.check
+
+      puts checker.errors unless checker.errors.empty?
+      exit checker.errors.empty? unless options[:autocorrect]
+
+      checker.write!
+    end
+  end
+end
diff --git a/tools/rail_inspector/lib/rail_inspector/configuring.rb b/tools/rail_inspector/lib/rail_inspector/configuring.rb
new file mode 100644
index 00000000000..debd0148490
--- /dev/null
+++ b/tools/rail_inspector/lib/rail_inspector/configuring.rb
@@ -0,0 +1,91 @@
+# frozen_string_literal: true
+
+require "pathname"
+require_relative "./configuring/check/general_configuration"
+require_relative "./configuring/check/framework_defaults"
+
+module RailInspector
+  class Configuring
+    class CachedParser
+      def initialize
+        @cache = {}
+      end
+
+      def call(path)
+        @cache[path] ||= SyntaxTree.parse(SyntaxTree.read(path))
+      end
+    end
+
+    DOC_PATH = "guides/source/configuring.md"
+    APPLICATION_CONFIGURATION_PATH =
+      "railties/lib/rails/application/configuration.rb"
+    NEW_FRAMEWORK_DEFAULTS_PATH =
+      "railties/lib/rails/generators/rails/app/templates/config/initializers/new_framework_defaults_%{version}.rb.tt"
+
+    class Doc
+      attr_accessor :general_config, :versioned_defaults
+
+      def initialize(content)
+        @before, @versioned_defaults, @general_config, @after =
+          content
+            .split("\n")
+            .slice_before do |line|
+              [
+                "### Versioned Default Values",
+                "### Rails General Configuration",
+                "### Configuring Assets"
+              ].include?(line)
+            end
+            .to_a
+      end
+
+      def to_s
+        (@before + @versioned_defaults + @general_config + @after).join("\n") +
+          "\n"
+      end
+    end
+
+    attr_reader :errors, :parser
+
+    def initialize(rails_path)
+      @errors = []
+      @parser = CachedParser.new
+      @rails_path = Pathname.new(rails_path)
+    end
+
+    def check
+      [Check::GeneralConfiguration, Check::FrameworkDefaults].each do |check|
+        check.new(self).check
+      end
+    end
+
+    def doc
+      @doc ||=
+        begin
+          content = File.read(doc_path)
+          Configuring::Doc.new(content)
+        end
+    end
+
+    def parse(relative_path)
+      parser.call(@rails_path.join(relative_path))
+    end
+
+    def read(relative_path)
+      File.read(@rails_path.join(relative_path))
+    end
+
+    def rails_version
+      @rails_version ||= File.read(@rails_path.join("RAILS_VERSION")).to_f.to_s
+    end
+
+    def write!
+      File.write(doc_path, doc.to_s)
+    end
+
+    private
+      def doc_path
+        @rails_path.join(DOC_PATH)
+      end
+  end
+end
diff --git a/tools/rail_inspector/lib/rail_inspector/configuring/check/framework_defaults.rb b/tools/rail_inspector/lib/rail_inspector/configuring/check/framework_defaults.rb
new file mode 100644
index 00000000000..b41ea1fc26c
--- /dev/null
+++ b/tools/rail_inspector/lib/rail_inspector/configuring/check/framework_defaults.rb
@@ -0,0 +1,134 @@
+# frozen_string_literal: true
+
+require "tempfile"
+require_relative "../../visitor/framework_default"
+
+module RailInspector
+  class Configuring
+    module Check
+      class FrameworkDefaults
+        class NewFrameworkDefaultsFile
+          attr_reader :checker, :visitor
+
+          def initialize(checker, visitor)
+            @checker = checker
+            @visitor = visitor
+          end
+
+          def check
+            visitor.config_map[checker.rails_version].each_key do |config|
+              app_config = config.gsub(/^self/, "config")
+
+              next if defaults_file_content.include? app_config
+
+              add_error(config)
+            end
+          end
+
+          private
+            def add_error(config)
+              checker.errors << <<~MESSAGE
+              #{new_framework_defaults_path}
+              Missing: #{config}
+
+              MESSAGE
+            end
+
+            def defaults_file_content
+              @defaults_file_content ||= checker.read(new_framework_defaults_path)
+            end
+
+            def new_framework_defaults_path
+              NEW_FRAMEWORK_DEFAULTS_PATH %
+                { version: checker.rails_version.tr(".", "_") }
+            end
+        end
+
+        attr_reader :checker
+
+        def initialize(checker)
+          @checker = checker
+        end
+
+        def check
+          header, *defaults_by_version = documented_defaults
+
+          NewFrameworkDefaultsFile.new(checker, visitor).check
+
+          checker.doc.versioned_defaults =
+            header +
+              defaults_by_version
+                .map { |defaults| check_defaults(defaults) }
+                .flatten
+        end
+
+        private
+          def app_config_tree
+            checker.parse(APPLICATION_CONFIGURATION_PATH)
+          end
+
+          def check_defaults(defaults)
+            header, configs = defaults[0], defaults[2, defaults.length - 3]
+
+            version = header.match(/\d\.\d/)[0]
+
+            generated_doc =
+              visitor.config_map[version]
+                .map do |config, value|
+                  full_config =
+                    case config
+                    when /^[A-Z]/
+                      config
+                    when /^self/
+                      config.sub("self", "config")
+                    else
+                      "config.#{config}"
+                    end
+
+                  "- [`#{full_config}`](##{full_config.tr("._", "-").downcase}): `#{value}`"
+                end
+                .sort
+
+            config_diff =
+              Tempfile.create("expected") do |doc|
+                doc << generated_doc.join("\n")
+                doc.flush
+
+                Tempfile.create("actual") do |code|
+                  code << configs.join("\n")
+                  code.flush
+
+                  `git diff --color --no-index #{doc.path} #{code.path}`
+                end
+              end
+
+            checker.errors << <<~MESSAGE unless config_diff.empty?
+              #{APPLICATION_CONFIGURATION_PATH}: Incorrect load_defaults docs
+              --- Expected
+              +++ Actual
+              #{config_diff.split("\n")[5..].join("\n")}
+            MESSAGE
+
+            [header, "", *generated_doc, ""]
+          end
+
+          def documented_defaults
+            checker
+              .doc
+              .versioned_defaults
+              .slice_before { |line| line.start_with?("####") }
+              .to_a
+          end
+
+          def visitor
+            @visitor ||=
+              begin
+                visitor = Visitor::FrameworkDefault.new
+                visitor.visit(app_config_tree)
+                visitor
+              end
+          end
+      end
+    end
+  end
+end
diff --git a/tools/rail_inspector/lib/rail_inspector/configuring/check/general_configuration.rb b/tools/rail_inspector/lib/rail_inspector/configuring/check/general_configuration.rb
new file mode 100644
index 00000000000..32d57eb85b3
--- /dev/null
+++ b/tools/rail_inspector/lib/rail_inspector/configuring/check/general_configuration.rb
@@ -0,0 +1,67 @@
+# frozen_string_literal: true
+
+require_relative "../../visitor/attribute"
+
+module RailInspector
+  class Configuring
+    module Check
+      class GeneralConfiguration
+        attr_reader :checker
+
+        def initialize(checker)
+          @checker = checker
+        end
+
+        def check
+          header, *config_sections = documented_general_config
+
+          non_nested_accessors =
+            general_accessors.reject do |a|
+              config_sections.any? { |section| /\.#{a}\./.match?(section[0]) }
+            end
+
+          non_nested_accessors.each do |accessor|
+            config_header = "#### `config.#{accessor}`"
+
+            unless config_sections.any? { |section| section[0] == config_header }
+              checker.errors << config_header
+              config_sections << [config_header, "", "FIXME", ""]
+            end
+          end
+
+          checker.doc.general_config =
+            [header] +
+              config_sections.sort_by { |section| section[0].split("`")[1] }
+        end
+
+        private
+          APP_CONFIG_CONST = "Rails::Application::Configuration"
+
+          def app_config_tree
+            checker.parse(APPLICATION_CONFIGURATION_PATH)
+          end
+
+          def documented_general_config
+            checker
+              .doc
+              .general_config
+              .slice_before { |line| line.start_with?("####") }
+              .to_a
+          end
+
+          def general_accessors
+            visitor.attribute_map[APP_CONFIG_CONST]["attr_accessor"]
+          end
+
+          def visitor
+            @visitor ||=
+              begin
+                visitor = Visitor::Attribute.new
+                visitor.visit(app_config_tree)
+                visitor
+              end
+          end
+      end
+    end
+  end
+end
diff --git a/tools/rail_inspector/lib/rail_inspector/version.rb b/tools/rail_inspector/lib/rail_inspector/version.rb
new file mode 100644
index 00000000000..cfc482cf62a
--- /dev/null
+++ b/tools/rail_inspector/lib/rail_inspector/version.rb
@@ -0,0 +1,5 @@
+# frozen_string_literal: true
+
+module RailInspector
+  VERSION = "0.0.2"
+end
diff --git a/tools/rail_inspector/lib/rail_inspector/visitor/attribute.rb b/tools/rail_inspector/lib/rail_inspector/visitor/attribute.rb
new file mode 100644
index 00000000000..cc1166c741b
--- /dev/null
+++ b/tools/rail_inspector/lib/rail_inspector/visitor/attribute.rb
@@ -0,0 +1,44 @@
+# frozen_string_literal: true
+
+require "set"
+require "syntax_tree"
+
+module RailInspector
+  module Visitor
+    class Attribute < SyntaxTree::Visitor
+      attr_reader :attribute_map
+
+      def initialize
+        @attribute_map = {}
+        @namespace_stack = []
+      end
+
+      def with_namespace(node)
+        @namespace_stack << node.constant.constant.value
+        visit_child_nodes(node)
+        @namespace_stack.pop
+      end
+
+      visit_method alias_method :visit_module, :with_namespace
+
+      visit_method alias_method :visit_class, :with_namespace
+
+      visit_method def visit_command(node)
+        attr_access = node.message.value
+        return unless ATTRIBUTE_METHODS.include?(attr_access)
+
+        full_namespace = @namespace_stack.join("::")
+
+        @attribute_map[full_namespace] ||= {}
+        @attribute_map[full_namespace][attr_access] ||= Set.new
+
+        attributes = node.arguments.parts.map { |p| p.value.value }
+
+        @attribute_map[full_namespace][attr_access].merge(attributes)
+      end
+
+      private
+        ATTRIBUTE_METHODS = %w[attr_accessor attr_reader attr_writer]
+    end
+  end
+end
diff --git a/tools/rail_inspector/lib/rail_inspector/visitor/framework_default.rb b/tools/rail_inspector/lib/rail_inspector/visitor/framework_default.rb
new file mode 100644
index 00000000000..7bf6c981035
--- /dev/null
+++ b/tools/rail_inspector/lib/rail_inspector/visitor/framework_default.rb
@@ -0,0 +1,132 @@
+# frozen_string_literal: true
+
+require "syntax_tree"
+
+require_relative "./hash_to_string"
+require_relative "./multiline_to_string"
+
+module RailInspector
+  module Visitor
+    class FrameworkDefault
+      TargetVersionCaseFinder =
+        SyntaxTree::Search.new(
+          ->(node) do
+            node in SyntaxTree::Case[
+              value: SyntaxTree::CallNode[
+                receiver: SyntaxTree::VarRef[
+                  value: SyntaxTree::Ident[value: "target_version"]
+                ]
+              ]
+            ]
+          end
+        )
+
+      attr_reader :config_map
+
+      def initialize
+        @config_map = {}
+      end
+
+      def visit(node)
+        case_node, *others = TargetVersionCaseFinder.scan(node).to_a
+        raise "#{others.length} other cases?" unless others.empty?
+
+        visit_when(case_node.consequent)
+      end
+
+      private
+        def visit_when(node)
+          version = node.arguments.parts[0].parts[0].value
+
+          config_map[version] = VersionedConfig.new.config_for(node.statements)
+
+          visit_when(node.consequent) if node.consequent.is_a? SyntaxTree::When
+        end
+
+        class VersionedConfig < SyntaxTree::Visitor
+          attr_reader :configs
+
+          def initialize
+            @configs = {}
+            @framework_stack = []
+          end
+
+          def config_for(node)
+            visit(node)
+            @configs
+          end
+
+          visit_methods do
+            def visit_if(node)
+              unless new_framework = respond_to_framework?(node.predicate)
+                return super
+              end
+
+              if ENV["STRICT"] && current_framework
+                raise "Potentially nested framework? Current: '#{current_framework}', found: '#{new_framework}'"
+              end
+
+              @framework_stack << new_framework
+              super
+              @framework_stack.pop
+            end
+
+            def visit_assign(node)
+              assert_framework(node)
+
+              target = SyntaxTree::Formatter.format(nil, node.target)
+              value =
+                case node.value
+                when SyntaxTree::HashLiteral
+                  HashToString.new.tap { |v| v.visit(node.value) }.to_s
+                when SyntaxTree::StringConcat
+                  MultilineToString.new.tap { |v| v.visit(node.value) }.to_s
+                else
+                  SyntaxTree::Formatter.format(nil, node.value)
+                end
+              @configs[target] = value
+            end
+          end
+
+          private
+            def assert_framework(node)
+              framework =
+                case node.target.parent
+                in { value: SyntaxTree::Const } |
+                     { value: SyntaxTree::Kw[value: "self"] }
+                  nil
+                in receiver: { value: { value: framework } }
+                  framework
+                in value: { value: framework }
+                  framework
+                end
+
+              return if current_framework == framework
+
+              raise "Expected #{current_framework} to match #{framework}"
+            end
+
+            def current_framework
+              @framework_stack.last
+            end
+
+            def respond_to_framework?(node)
+              if node in SyntaxTree::CallNode[
+                   message: SyntaxTree::Ident[value: "respond_to?"],
+                   arguments: SyntaxTree::ArgParen[
+                     arguments: SyntaxTree::Args[
+                       parts: [
+                         SyntaxTree::SymbolLiteral[
+                           value: SyntaxTree::Ident[value: new_framework]
+                         ]
+                       ]
+                     ]
+                   ]
+                 ]
+                new_framework
+              end
+            end
+        end
+    end
+  end
+end
diff --git a/tools/rail_inspector/lib/rail_inspector/visitor/hash_to_string.rb b/tools/rail_inspector/lib/rail_inspector/visitor/hash_to_string.rb
new file mode 100644
index 00000000000..0b88bf875d0
--- /dev/null
+++ b/tools/rail_inspector/lib/rail_inspector/visitor/hash_to_string.rb
@@ -0,0 +1,66 @@
+# frozen_string_literal: true
+
+require "syntax_tree"
+
+module RailInspector
+  module Visitor
+    class HashToString < SyntaxTree::Visitor
+      attr_reader :to_s
+
+      def initialize
+        @to_s = +""
+      end
+
+      visit_methods do
+        def visit_assoc(node)
+          @to_s << " "
+          visit(node.key)
+
+          case node.key
+          when SyntaxTree::StringLiteral
+            @to_s << " => "
+          end
+
+          visit(node.value)
+        end
+
+        def visit_hash(node)
+          @to_s << "{"
+
+          if node.assocs.length > 0
+            visit(node.assocs[0])
+
+            if node.assocs.length > 1
+              node.assocs[1..-1].each do |a|
+                @to_s << ","
+                visit(a)
+              end
+            end
+            @to_s << " "
+          end
+
+          @to_s << "}"
+        end
+
+        def visit_int(node)
+          @to_s << node.value
+        end
+
+        def visit_kw(node)
+          @to_s << node.value
+        end
+
+        def visit_label(node)
+          @to_s << node.value
+          @to_s << " "
+        end
+
+        def visit_tstring_content(node)
+          @to_s << '"'
+          @to_s << node.value
+          @to_s << '"'
+        end
+      end
+    end
+  end
+end
diff --git a/tools/rail_inspector/lib/rail_inspector/visitor/multiline_to_string.rb b/tools/rail_inspector/lib/rail_inspector/visitor/multiline_to_string.rb
new file mode 100644
index 00000000000..64aa0d60e97
--- /dev/null
+++ b/tools/rail_inspector/lib/rail_inspector/visitor/multiline_to_string.rb
@@ -0,0 +1,27 @@
+# frozen_string_literal: true
+
+require "syntax_tree"
+
+module RailInspector
+  module Visitor
+    class MultilineToString < SyntaxTree::Visitor
+      attr_reader :to_s
+
+      def initialize
+        @to_s = +""
+      end
+
+      visit_methods do
+        def visit_string_concat(node)
+          @to_s << '"'
+          super(node)
+          @to_s << '"'
+        end
+
+        def visit_tstring_content(node)
+          @to_s << node.value
+        end
+      end
+    end
+  end
+end
diff --git a/tools/rail_inspector/rail_inspector.gemspec b/tools/rail_inspector/rail_inspector.gemspec
new file mode 100644
index 00000000000..1655e34810d
--- /dev/null
+++ b/tools/rail_inspector/rail_inspector.gemspec
@@ -0,0 +1,34 @@
+# frozen_string_literal: true
+
+require_relative "lib/rail_inspector/version"
+
+Gem::Specification.new do |spec|
+  spec.name = "rail_inspector"
+  spec.version = RailInspector::VERSION
+  spec.authors = ["Hartley McGuire"]
+  spec.email = ["skipkayhil@gmail.com"]
+
+  spec.summary = "A collection of linters for rails/rails"
+  spec.homepage = "https://github.com/skipkayhil/rail_inspector"
+  spec.license = "MIT"
+  spec.required_ruby_version = ">= 2.7.0"
+
+  spec.metadata["homepage_uri"] = spec.homepage
+  spec.metadata["source_code_uri"] = spec.homepage
+  # spec.metadata["changelog_uri"] = "TODO: Put your gem's CHANGELOG.md URL here."
+
+  # Specify which files should be added to the gem when it is released.
+  # The `git ls-files -z` loads the files in the RubyGem that have been added into git.
+  spec.files = Dir.chdir(__dir__) do
+    `git ls-files -z`.split("\x0").reject do |f|
+      (File.expand_path(f) == __FILE__) || f.start_with?(*%w[bin/ test/ spec/ features/ .git .circleci appveyor])
+    end
+  end
+  spec.bindir = "exe"
+  spec.executables = spec.files.grep(%r{\Aexe/}) { |f| File.basename(f) }
+  spec.require_paths = ["lib"]
+
+  # Uncomment to register a new dependency of your gem
+  spec.add_dependency "syntax_tree", "6.1.1"
+  spec.add_dependency "thor", "~> 1.0"
+end
diff --git a/tools/rail_inspector/test/fixtures/action_mailbox_83d85b2.md b/tools/rail_inspector/test/fixtures/action_mailbox_83d85b2.md
new file mode 100644
index 00000000000..0bb4a4e8e32
--- /dev/null
+++ b/tools/rail_inspector/test/fixtures/action_mailbox_83d85b2.md
@@ -0,0 +1,3 @@
+
+
+Please check [7-0-stable](https://github.com/rails/rails/blob/7-0-stable/actionmailbox/CHANGELOG.md) for previous changes.
diff --git a/tools/rail_inspector/test/fixtures/action_pack_69d504.md b/tools/rail_inspector/test/fixtures/action_pack_69d504.md
new file mode 100644
index 00000000000..d72abba38d2
--- /dev/null
+++ b/tools/rail_inspector/test/fixtures/action_pack_69d504.md
@@ -0,0 +1,10 @@
+*   This entry is not real but triggers the error because the next header is
+    incorrectly ambiguous when it isn't the top entry
+
+    *Hartley McGuire*
+
+*   Expand search field on `rails/info/routes` to also search **route name**, **http verb** and **controller#action**
+
+    *Jason Kotchoff*
+
+Please check [7-0-stable](https://github.com/rails/rails/blob/7-0-stable/actionpack/CHANGELOG.md) for previous changes.
diff --git a/tools/rail_inspector/test/fixtures/active_record_238432d.md b/tools/rail_inspector/test/fixtures/active_record_238432d.md
new file mode 100644
index 00000000000..3dc16286673
--- /dev/null
+++ b/tools/rail_inspector/test/fixtures/active_record_238432d.md
@@ -0,0 +1,300 @@
+*   Add ability to ignore tables by regexp for SQL schema dumps.
+
+    ```ruby
+    ActiveRecord::SchemaDumper.ignore_tables = [/^_/]
+    ```
+
+    *fatkodima*
+
+*   Avoid queries when performing calculations on contradictory relations.
+
+    Previously calculations would make a query even when passed a
+    contradiction, such as `User.where(id: []).count`. We no longer perform a
+    query in that scenario.
+
+    This applies to the following calculations: `count`, `sum`, `average`,
+    `minimum` and `maximum`
+
+    *Luan Vieira, John Hawthorn and Daniel Colson*
+
+*   Allow using aliased attributes with `insert_all`/`upsert_all`.
+
+    ```ruby
+    class Book < ApplicationRecord
+      alias_attribute :title, :name
+    end
+
+    Book.insert_all [{ title: "Remote", author_id: 1 }], returning: :title
+    ```
+
+    *fatkodima*
+
+*   Support encrypted attributes on columns with default db values.
+
+This adds support for encrypted attributes defined on columns with default values. 
+It will encrypt those values at creation time. Before, it would raise an
+error unless `config.active_record.encryption.support_unencrypted_data` was true.
+
+*Jorge Manrubia* and *Dima Fatko*
+
+*   Allow overriding `reading_request?` in `DatabaseSelector::Resolver`
+
+    The default implementation checks if a request is a `get?` or `head?`,
+    but you can now change it to anything you like. If the method returns true,
+    `Resolver#read` gets called meaning the request could be served by the
+    replica database.
+
+    *Alex Ghiculescu*
+
+*   Remove `ActiveRecord.legacy_connection_handling`.
+
+    *Eileen M. Uchitelle*
+
+*   `rails db:schema:{dump,load}` now checks `ENV["SCHEMA_FORMAT"]` before config
+
+    Since `rails db:structure:{dump,load}` was deprecated there wasn't a simple
+    way to dump a schema to both SQL and Ruby formats. You can now do this with
+    an environment variable. For example:
+
+    ```
+    SCHEMA_FORMAT=sql rake db:schema:dump
+    ```
+
+    *Alex Ghiculescu*
+
+*   Fixed MariaDB default function support.
+
+    Defaults would be written wrong in "db/schema.rb" and not work correctly
+    if using `db:schema:load`. Further more the function name would be
+    added as string content when saving new records.
+
+    *kaspernj*
+
+*   Add `active_record.destroy_association_async_batch_size` configuration
+
+    This allows applications to specify the maximum number of records that will
+    be destroyed in a single background job by the `dependent: :destroy_async`
+    association option. By default, the current behavior will remain the same:
+    when a parent record is destroyed, all dependent records will be destroyed
+    in a single background job. If the number of dependent records is greater
+    than this configuration, the records will be destroyed in multiple
+    background jobs.
+
+    *Nick Holden*
+
+*   Fix `remove_foreign_key` with `:if_exists` option when foreign key actually exists.
+
+    *fatkodima*
+
+*   Remove `--no-comments` flag in structure dumps for PostgreSQL
+
+    This broke some apps that used custom schema comments. If you don't want
+    comments in your structure dump, you can use:
+
+    ```ruby
+    ActiveRecord::Tasks::DatabaseTasks.structure_dump_flags = ['--no-comments']
+    ```
+
+    *Alex Ghiculescu*
+
+*   Reduce the memory footprint of fixtures accessors.
+
+    Until now fixtures accessors were eagerly defined using `define_method`.
+    So the memory usage was directly dependent of the number of fixtures and
+    test suites.
+
+    Instead fixtures accessors are now implemented with `method_missing`,
+    so they incur much less memory and CPU overhead.
+
+    *Jean Boussier*
+
+*   Fix `config.active_record.destroy_association_async_job` configuration
+
+    `config.active_record.destroy_association_async_job` should allow
+    applications to specify the job that will be used to destroy associated
+    records in the background for `has_many` associations with the
+    `dependent: :destroy_async` option. Previously, that was ignored, which
+    meant the default `ActiveRecord::DestroyAssociationAsyncJob` always
+    destroyed records in the background.
+
+    *Nick Holden*
+
+*   Fix `change_column_comment` to preserve column's AUTO_INCREMENT in the MySQL adapter
+
+    *fatkodima*
+
+*   Fix quoting of `ActiveSupport::Duration` and `Rational` numbers in the MySQL adapter.
+
+    *Kevin McPhillips*
+
+*   Allow column name with COLLATE (e.g., title COLLATE "C") as safe SQL string
+
+    *Shugo Maeda*
+
+*   Permit underscores in the VERSION argument to database rake tasks.
+
+    *Eddie Lebow*
+
+*   Reversed the order of `INSERT` statements in `structure.sql` dumps
+
+    This should decrease the likelihood of merge conflicts. New migrations
+    will now be added at the top of the list.
+
+    For existing apps, there will be a large diff the next time `structure.sql`
+    is generated.
+
+    *Alex Ghiculescu*, *Matt Larraz*
+
+*   Fix PG.connect keyword arguments deprecation warning on ruby 2.7
+
+    Fixes #44307.
+
+    *Nikita Vasilevsky*
+
+*   Fix dropping DB connections after serialization failures and deadlocks.
+
+    Prior to 6.1.4, serialization failures and deadlocks caused rollbacks to be
+    issued for both real transactions and savepoints. This breaks MySQL which
+    disallows rollbacks of savepoints following a deadlock.
+
+    6.1.4 removed these rollbacks, for both transactions and savepoints, causing
+    the DB connection to be left in an unknown state and thus discarded.
+
+    These rollbacks are now restored, except for savepoints on MySQL.
+
+    *Thomas Morgan*
+
+*   Make `ActiveRecord::ConnectionPool` Fiber-safe
+
+    When `ActiveSupport::IsolatedExecutionState.isolation_level` is set to `:fiber`,
+    the connection pool now supports multiple Fibers from the same Thread checking
+    out connections from the pool.
+
+    *Alex Matchneer*
+
+*   Add `update_attribute!` to `ActiveRecord::Persistence`
+
+    Similar to `update_attribute`, but raises `ActiveRecord::RecordNotSaved` when a `before_*` callback throws `:abort`.
+
+    ```ruby
+    class Topic < ActiveRecord::Base
+      before_save :check_title
+
+      def check_title
+        throw(:abort) if title == "abort"
+      end
+    end
+
+    topic = Topic.create(title: "Test Title")
+    # #=> #<Topic title: "Test Title">
+    topic.update_attribute!(:title, "Another Title")
+    # #=> #<Topic title: "Another Title">
+    topic.update_attribute!(:title, "abort")
+    # raises ActiveRecord::RecordNotSaved
+    ```
+
+    *Drew Tempelmeyer*
+
+*   Avoid loading every record in `ActiveRecord::Relation#pretty_print`
+
+    ```ruby
+    # Before
+    pp Foo.all # Loads the whole table.
+
+    # After
+    pp Foo.all # Shows 10 items and an ellipsis.
+    ```
+
+    *Ulysse Buonomo*
+
+*   Change `QueryMethods#in_order_of` to drop records not listed in values.
+
+    `in_order_of` now filters down to the values provided, to match the behavior of the `Enumerable` version.
+
+    *Kevin Newton*
+
+*   Allow named expression indexes to be revertible.
+
+    Previously, the following code would raise an error in a reversible migration executed while rolling back, due to the index name not being used in the index removal.
+
+    ```ruby
+    add_index(:settings, "(data->'property')", using: :gin, name: :index_settings_data_property)
+    ```
+
+    Fixes #43331.
+
+    *Oliver Günther*
+
+*   Fix incorrect argument in PostgreSQL structure dump tasks.
+
+    Updating the `--no-comment` argument added in Rails 7 to the correct `--no-comments` argument.
+
+    *Alex Dent*
+
+*   Fix migration compatibility to create SQLite references/belongs_to column as integer when migration version is 6.0.
+
+    Reference/belongs_to in migrations with version 6.0 were creating columns as
+    bigint instead of integer for the SQLite Adapter.
+
+    *Marcelo Lauxen*
+
+*   Add a deprecation warning when `prepared_statements` configuration is not
+    set for the mysql2 adapter.
+
+    *Thiago Araujo and Stefanni Brasil*
+
+*   Fix `QueryMethods#in_order_of` to handle empty order list.
+
+    ```ruby
+    Post.in_order_of(:id, []).to_a
+    ```
+
+    Also more explicitly set the column as secondary order, so that any other
+    value is still ordered.
+
+    *Jean Boussier*
+
+*   Fix quoting of column aliases generated by calculation methods.
+
+    Since the alias is derived from the table name, we can't assume the result
+    is a valid identifier.
+
+    ```ruby
+    class Test < ActiveRecord::Base
+      self.table_name = '1abc'
+    end
+    Test.group(:id).count
+    # syntax error at or near "1" (ActiveRecord::StatementInvalid)
+    # LINE 1: SELECT COUNT(*) AS count_all, "1abc"."id" AS 1abc_id FROM "1...
+    ```
+
+    *Jean Boussier*
+
+*   Add `authenticate_by` when using `has_secure_password`.
+
+    `authenticate_by` is intended to replace code like the following, which
+    returns early when a user with a matching email is not found:
+
+    ```ruby
+    User.find_by(email: "...")&.authenticate("...")
+    ```
+
+    Such code is vulnerable to timing-based enumeration attacks, wherein an
+    attacker can determine if a user account with a given email exists. After
+    confirming that an account exists, the attacker can try passwords associated
+    with that email address from other leaked databases, in case the user
+    re-used a password across multiple sites (a common practice). Additionally,
+    knowing an account email address allows the attacker to attempt a targeted
+    phishing ("spear phishing") attack.
+
+    `authenticate_by` addresses the vulnerability by taking the same amount of
+    time regardless of whether a user with a matching email is found:
+
+    ```ruby
+    User.authenticate_by(email: "...", password: "...")
+    ```
+
+    *Jonathan Hefner*
+
+
+Please check [7-0-stable](https://github.com/rails/rails/blob/7-0-stable/activerecord/CHANGELOG.md) for previous changes.
diff --git a/tools/rail_inspector/test/fixtures/active_record_51852d2.md b/tools/rail_inspector/test/fixtures/active_record_51852d2.md
new file mode 100644
index 00000000000..e0572ba7490
--- /dev/null
+++ b/tools/rail_inspector/test/fixtures/active_record_51852d2.md
@@ -0,0 +1,190 @@
+*   Fix `config.active_record.destroy_association_async_job` configuration
+
+    `config.active_record.destroy_association_async_job` should allow
+    applications to specify the job that will be used to destroy associated
+    records in the background for `has_many` associations with the
+    `dependent: :destroy_async` option. Previously, that was ignored, which
+    meant the default `ActiveRecord::DestroyAssociationAsyncJob` always
+    destroyed records in the background.
+
+    *Nick Holden*
+
+* Fix `change_column_comment` to preserve column's AUTO_INCREMENT in the MySQL adapter
+
+    *fatkodima*
+
+*   Fix quoting of `ActiveSupport::Duration` and `Rational` numbers in the MySQL adapter.
+
+    *Kevin McPhillips*
+
+*   Allow column name with COLLATE (e.g., title COLLATE "C") as safe SQL string
+
+    *Shugo Maeda*
+
+*   Permit underscores in the VERSION argument to database rake tasks.
+
+    *Eddie Lebow*
+
+*   Reversed the order of `INSERT` statements in `structure.sql` dumps
+
+    This should decrease the likelihood of merge conflicts. New migrations
+    will now be added at the top of the list.
+
+    For existing apps, there will be a large diff the next time `structure.sql`
+    is generated.
+
+    *Alex Ghiculescu*, *Matt Larraz*
+
+*   Fix PG.connect keyword arguments deprecation warning on ruby 2.7
+
+    Fixes #44307.
+
+    *Nikita Vasilevsky*
+
+*   Fix dropping DB connections after serialization failures and deadlocks.
+
+    Prior to 6.1.4, serialization failures and deadlocks caused rollbacks to be
+    issued for both real transactions and savepoints. This breaks MySQL which
+    disallows rollbacks of savepoints following a deadlock.
+
+    6.1.4 removed these rollbacks, for both transactions and savepoints, causing
+    the DB connection to be left in an unknown state and thus discarded.
+
+    These rollbacks are now restored, except for savepoints on MySQL.
+
+    *Thomas Morgan*
+
+*   Make `ActiveRecord::ConnectionPool` Fiber-safe
+
+    When `ActiveSupport::IsolatedExecutionState.isolation_level` is set to `:fiber`,
+    the connection pool now supports multiple Fibers from the same Thread checking
+    out connections from the pool.
+
+    *Alex Matchneer*
+
+*   Add `update_attribute!` to `ActiveRecord::Persistence`
+
+    Similar to `update_attribute`, but raises `ActiveRecord::RecordNotSaved` when a `before_*` callback throws `:abort`.
+
+    ```ruby
+    class Topic < ActiveRecord::Base
+      before_save :check_title
+
+      def check_title
+        throw(:abort) if title == "abort"
+      end
+    end
+
+    topic = Topic.create(title: "Test Title")
+    # #=> #<Topic title: "Test Title">
+    topic.update_attribute!(:title, "Another Title")
+    # #=> #<Topic title: "Another Title">
+    topic.update_attribute!(:title, "abort")
+    # raises ActiveRecord::RecordNotSaved
+    ```
+
+    *Drew Tempelmeyer*
+
+*   Avoid loading every record in `ActiveRecord::Relation#pretty_print`
+
+    ```ruby
+    # Before
+    pp Foo.all # Loads the whole table.
+
+    # After
+    pp Foo.all # Shows 10 items and an ellipsis.
+    ```
+
+    *Ulysse Buonomo*
+
+*   Change `QueryMethods#in_order_of` to drop records not listed in values.
+
+    `in_order_of` now filters down to the values provided, to match the behavior of the `Enumerable` version.
+
+    *Kevin Newton*
+
+*   Allow named expression indexes to be revertible.
+
+    Previously, the following code would raise an error in a reversible migration executed while rolling back, due to the index name not being used in the index removal.
+
+    ```ruby
+    add_index(:settings, "(data->'property')", using: :gin, name: :index_settings_data_property)
+    ```
+
+    Fixes #43331.
+
+    *Oliver Günther*
+
+*   Fix incorrect argument in PostgreSQL structure dump tasks.
+
+    Updating the `--no-comment` argument added in Rails 7 to the correct `--no-comments` argument.
+
+    *Alex Dent*
+
+*   Fix migration compatibility to create SQLite references/belongs_to column as integer when migration version is 6.0.
+
+    Reference/belongs_to in migrations with version 6.0 were creating columns as
+    bigint instead of integer for the SQLite Adapter.
+
+    *Marcelo Lauxen*
+
+*   Add a deprecation warning when `prepared_statements` configuration is not
+    set for the mysql2 adapter.
+
+    *Thiago Araujo and Stefanni Brasil*
+
+*   Fix `QueryMethods#in_order_of` to handle empty order list.
+
+    ```ruby
+    Post.in_order_of(:id, []).to_a
+    ```
+
+    Also more explicitly set the column as secondary order, so that any other
+    value is still ordered.
+
+    *Jean Boussier*
+
+*   Fix quoting of column aliases generated by calculation methods.
+
+    Since the alias is derived from the table name, we can't assume the result
+    is a valid identifier.
+
+    ```ruby
+    class Test < ActiveRecord::Base
+      self.table_name = '1abc'
+    end
+    Test.group(:id).count
+    # syntax error at or near "1" (ActiveRecord::StatementInvalid)
+    # LINE 1: SELECT COUNT(*) AS count_all, "1abc"."id" AS 1abc_id FROM "1...
+    ```
+
+    *Jean Boussier*
+
+*   Add `authenticate_by` when using `has_secure_password`.
+
+    `authenticate_by` is intended to replace code like the following, which
+    returns early when a user with a matching email is not found:
+
+    ```ruby
+    User.find_by(email: "...")&.authenticate("...")
+    ```
+
+    Such code is vulnerable to timing-based enumeration attacks, wherein an
+    attacker can determine if a user account with a given email exists. After
+    confirming that an account exists, the attacker can try passwords associated
+    with that email address from other leaked databases, in case the user
+    re-used a password across multiple sites (a common practice). Additionally,
+    knowing an account email address allows the attacker to attempt a targeted
+    phishing ("spear phishing") attack.
+
+    `authenticate_by` addresses the vulnerability by taking the same amount of
+    time regardless of whether a user with a matching email is found:
+
+    ```ruby
+    User.authenticate_by(email: "...", password: "...")
+    ```
+
+    *Jonathan Hefner*
+
+
+Please check [7-0-stable](https://github.com/rails/rails/blob/7-0-stable/activerecord/CHANGELOG.md) for previous changes.
diff --git a/tools/rail_inspector/test/fixtures/active_record_936a862.md b/tools/rail_inspector/test/fixtures/active_record_936a862.md
new file mode 100644
index 00000000000..925a1a37428
--- /dev/null
+++ b/tools/rail_inspector/test/fixtures/active_record_936a862.md
@@ -0,0 +1,476 @@
+*   Introduce strategy pattern for executing migrations.
+
+    By default, migrations will use a strategy object that delegates the method
+    to the connection adapter. Consumers can implement custom strategy objects
+    to change how their migrations run.
+
+    *Adrianna Chang*
+
+*   Add adapter option disallowing foreign keys
+
+    This adds a new option to be added to `database.yml` which enables skipping
+    foreign key constraints usage even if the underlying database supports them.
+
+    Usage:
+    ```yaml
+    development:
+        <<: *default
+        database: db/development.sqlite3
+        foreign_keys: false
+    ```
+
+    *Paulo Barros*
+
+*   Add configurable deprecation warning for singular associations
+
+    This adds a deprecation warning when using the plural name of a singular associations in `where`.
+    It is possible to opt into the new more performant behavior with `config.active_record.allow_deprecated_singular_associations_name = false`
+
+    *Adam Hess*
+
+*   Run transactional callbacks on the freshest instance to save a given 
+    record within a transaction.
+
+    When multiple Active Record instances change the same record within a 
+    transaction, Rails runs `after_commit` or `after_rollback` callbacks for 
+    only one of them. `config.active_record.run_commit_callbacks_on_first_saved_instances_in_transaction` 
+    was added to specify how Rails chooses which instance receives the 
+    callbacks. The framework defaults were changed to use the new logic.
+
+    When `config.active_record.run_commit_callbacks_on_first_saved_instances_in_transaction` 
+    is `true`, transactional callbacks are run on the first instance to save, 
+    even though its instance state may be stale.
+
+    When it is `false`, which is the new framework default starting with version 
+    7.1, transactional callbacks are run on the instances with the freshest 
+    instance state. Those instances are chosen as follows:
+
+    - In general, run transactional callbacks on the last instance to save a 
+      given record within the transaction.
+    - There are two exceptions:
+        - If the record is created within the transaction, then updated by 
+          another instance, `after_create_commit` callbacks will be run on the 
+          second instance. This is instead of the `after_update_commit` 
+          callbacks that would naively be run based on that instance’s state.
+        - If the record is destroyed within the transaction, then 
+          `after_destroy_commit` callbacks will be fired on the last destroyed 
+          instance, even if a stale instance subsequently performed an update 
+          (which will have affected 0 rows).
+
+    *Cameron Bothner and Mitch Vollebregt*
+
+*   Enable strict strings mode for `SQLite3Adapter`.
+
+    Configures SQLite with a strict strings mode, which disables double-quoted string literals.
+
+    SQLite has some quirks around double-quoted string literals.
+    It first tries to consider double-quoted strings as identifier names, but if they don't exist
+    it then considers them as string literals. Because of this, typos can silently go unnoticed.
+    For example, it is possible to create an index for a non existing column.
+    See [SQLite documentation](https://www.sqlite.org/quirks.html#double_quoted_string_literals_are_accepted) for more details.
+
+    If you don't want this behavior, you can disable it via:
+
+    ```ruby
+    # config/application.rb
+    config.active_record.sqlite3_adapter_strict_strings_by_default = false
+    ```
+
+    Fixes #27782.
+
+    *fatkodima*, *Jean Boussier*
+
+*   Resolve issue where a relation cache_version could be left stale.
+
+    Previously, when `reset` was called on a relation object it did not reset the cache_versions
+    ivar. This led to a confusing situation where despite having the correct data the relation
+    still reported a stale cache_version.
+
+    Usage:
+
+    ```ruby
+    developers = Developer.all
+    developers.cache_version
+
+    Developer.update_all(updated_at: Time.now.utc + 1.second)
+
+    developers.cache_version # Stale cache_version
+    developers.reset
+    developers.cache_version # Returns the current correct cache_version
+    ```
+
+    Fixes #45341.
+
+    *Austen Madden*
+
+*   Add support for exclusion constraints (PostgreSQL-only).
+
+    ```ruby
+    add_exclusion_constraint :invoices, "daterange(start_date, end_date) WITH &&", using: :gist, name: "invoices_date_overlap"
+    remove_exclusion_constraint :invoices, name: "invoices_date_overlap"
+    ```
+
+    See PostgreSQL's [`CREATE TABLE ... EXCLUDE ...`](https://www.postgresql.org/docs/12/sql-createtable.html#SQL-CREATETABLE-EXCLUDE) documentation for more on exclusion constraints.
+
+    *Alex Robbin*
+
+*   `change_column_null` raises if a non-boolean argument is provided
+
+    Previously if you provided a non-boolean argument, `change_column_null` would
+    treat it as truthy and make your column nullable. This could be surprising, so now
+    the input must be either `true` or `false`.
+
+    ```ruby
+    change_column_null :table, :column, true # good
+    change_column_null :table, :column, false # good
+    change_column_null :table, :column, from: true, to: false # raises (previously this made the column nullable)
+    ```
+
+    *Alex Ghiculescu*
+
+*   Enforce limit on table names length.
+
+    Fixes #45130.
+
+    *fatkodima*
+
+*   Adjust the minimum MariaDB version for check constraints support.
+
+    *Eddie Lebow*
+
+*   Fix Hstore deserialize regression.
+
+    *edsharp*
+
+*   Add validity for PostgreSQL indexes.
+
+    ```ruby
+    connection.index_exists?(:users, :email, valid: true)
+    connection.indexes(:users).select(&:valid?)
+    ```
+
+    *fatkodima*
+
+*   Fix eager loading for models without primary keys.
+
+    *Anmol Chopra*, *Matt Lawrence*, and *Jonathan Hefner*
+
+*   Avoid validating a unique field if it has not changed and is backed by a unique index.
+
+    Previously, when saving a record, ActiveRecord will perform an extra query to check for the uniqueness of
+    each attribute having a `uniqueness` validation, even if that attribute hasn't changed.
+    If the database has the corresponding unique index, then this validation can never fail for persisted records,
+    and we could safely skip it.
+
+    *fatkodima*
+
+*   Stop setting `sql_auto_is_null`
+
+    Since version 5.5 the default has been off, we no longer have to manually turn it off.
+
+    *Adam Hess*
+
+*   Fix `touch` to raise an error for readonly columns.
+
+    *fatkodima*
+
+*   Add ability to ignore tables by regexp for SQL schema dumps.
+
+    ```ruby
+    ActiveRecord::SchemaDumper.ignore_tables = [/^_/]
+    ```
+
+    *fatkodima*
+
+*   Avoid queries when performing calculations on contradictory relations.
+
+    Previously calculations would make a query even when passed a
+    contradiction, such as `User.where(id: []).count`. We no longer perform a
+    query in that scenario.
+
+    This applies to the following calculations: `count`, `sum`, `average`,
+    `minimum` and `maximum`
+
+    *Luan Vieira, John Hawthorn and Daniel Colson*
+
+*   Allow using aliased attributes with `insert_all`/`upsert_all`.
+
+    ```ruby
+    class Book < ApplicationRecord
+      alias_attribute :title, :name
+    end
+
+    Book.insert_all [{ title: "Remote", author_id: 1 }], returning: :title
+    ```
+
+    *fatkodima*
+
+*   Support encrypted attributes on columns with default db values.
+
+    This adds support for encrypted attributes defined on columns with default values.
+    It will encrypt those values at creation time. Before, it would raise an
+    error unless `config.active_record.encryption.support_unencrypted_data` was true.
+
+    *Jorge Manrubia* and *Dima Fatko*
+
+*   Allow overriding `reading_request?` in `DatabaseSelector::Resolver`
+
+    The default implementation checks if a request is a `get?` or `head?`,
+    but you can now change it to anything you like. If the method returns true,
+    `Resolver#read` gets called meaning the request could be served by the
+    replica database.
+
+    *Alex Ghiculescu*
+
+*   Remove `ActiveRecord.legacy_connection_handling`.
+
+    *Eileen M. Uchitelle*
+
+*   `rails db:schema:{dump,load}` now checks `ENV["SCHEMA_FORMAT"]` before config
+
+    Since `rails db:structure:{dump,load}` was deprecated there wasn't a simple
+    way to dump a schema to both SQL and Ruby formats. You can now do this with
+    an environment variable. For example:
+
+    ```
+    SCHEMA_FORMAT=sql rake db:schema:dump
+    ```
+
+    *Alex Ghiculescu*
+
+*   Fixed MariaDB default function support.
+
+    Defaults would be written wrong in "db/schema.rb" and not work correctly
+    if using `db:schema:load`. Further more the function name would be
+    added as string content when saving new records.
+
+    *kaspernj*
+
+*   Add `active_record.destroy_association_async_batch_size` configuration
+
+    This allows applications to specify the maximum number of records that will
+    be destroyed in a single background job by the `dependent: :destroy_async`
+    association option. By default, the current behavior will remain the same:
+    when a parent record is destroyed, all dependent records will be destroyed
+    in a single background job. If the number of dependent records is greater
+    than this configuration, the records will be destroyed in multiple
+    background jobs.
+
+    *Nick Holden*
+
+*   Fix `remove_foreign_key` with `:if_exists` option when foreign key actually exists.
+
+    *fatkodima*
+
+*   Remove `--no-comments` flag in structure dumps for PostgreSQL
+
+    This broke some apps that used custom schema comments. If you don't want
+    comments in your structure dump, you can use:
+
+    ```ruby
+    ActiveRecord::Tasks::DatabaseTasks.structure_dump_flags = ['--no-comments']
+    ```
+
+    *Alex Ghiculescu*
+
+*   Reduce the memory footprint of fixtures accessors.
+
+    Until now fixtures accessors were eagerly defined using `define_method`.
+    So the memory usage was directly dependent of the number of fixtures and
+    test suites.
+
+    Instead fixtures accessors are now implemented with `method_missing`,
+    so they incur much less memory and CPU overhead.
+
+    *Jean Boussier*
+
+*   Fix `config.active_record.destroy_association_async_job` configuration
+
+    `config.active_record.destroy_association_async_job` should allow
+    applications to specify the job that will be used to destroy associated
+    records in the background for `has_many` associations with the
+    `dependent: :destroy_async` option. Previously, that was ignored, which
+    meant the default `ActiveRecord::DestroyAssociationAsyncJob` always
+    destroyed records in the background.
+
+    *Nick Holden*
+
+*   Fix `change_column_comment` to preserve column's AUTO_INCREMENT in the MySQL adapter
+
+    *fatkodima*
+
+*   Fix quoting of `ActiveSupport::Duration` and `Rational` numbers in the MySQL adapter.
+
+    *Kevin McPhillips*
+
+*   Allow column name with COLLATE (e.g., title COLLATE "C") as safe SQL string
+
+    *Shugo Maeda*
+
+*   Permit underscores in the VERSION argument to database rake tasks.
+
+    *Eddie Lebow*
+
+*   Reversed the order of `INSERT` statements in `structure.sql` dumps
+
+    This should decrease the likelihood of merge conflicts. New migrations
+    will now be added at the top of the list.
+
+    For existing apps, there will be a large diff the next time `structure.sql`
+    is generated.
+
+    *Alex Ghiculescu*, *Matt Larraz*
+
+*   Fix PG.connect keyword arguments deprecation warning on ruby 2.7
+
+    Fixes #44307.
+
+    *Nikita Vasilevsky*
+
+*   Fix dropping DB connections after serialization failures and deadlocks.
+
+    Prior to 6.1.4, serialization failures and deadlocks caused rollbacks to be
+    issued for both real transactions and savepoints. This breaks MySQL which
+    disallows rollbacks of savepoints following a deadlock.
+
+    6.1.4 removed these rollbacks, for both transactions and savepoints, causing
+    the DB connection to be left in an unknown state and thus discarded.
+
+    These rollbacks are now restored, except for savepoints on MySQL.
+
+    *Thomas Morgan*
+
+*   Make `ActiveRecord::ConnectionPool` Fiber-safe
+
+    When `ActiveSupport::IsolatedExecutionState.isolation_level` is set to `:fiber`,
+    the connection pool now supports multiple Fibers from the same Thread checking
+    out connections from the pool.
+
+    *Alex Matchneer*
+
+*   Add `update_attribute!` to `ActiveRecord::Persistence`
+
+    Similar to `update_attribute`, but raises `ActiveRecord::RecordNotSaved` when a `before_*` callback throws `:abort`.
+
+    ```ruby
+    class Topic < ActiveRecord::Base
+      before_save :check_title
+
+      def check_title
+        throw(:abort) if title == "abort"
+      end
+    end
+
+    topic = Topic.create(title: "Test Title")
+    # #=> #<Topic title: "Test Title">
+    topic.update_attribute!(:title, "Another Title")
+    # #=> #<Topic title: "Another Title">
+    topic.update_attribute!(:title, "abort")
+    # raises ActiveRecord::RecordNotSaved
+    ```
+
+    *Drew Tempelmeyer*
+
+*   Avoid loading every record in `ActiveRecord::Relation#pretty_print`
+
+    ```ruby
+    # Before
+    pp Foo.all # Loads the whole table.
+
+    # After
+    pp Foo.all # Shows 10 items and an ellipsis.
+    ```
+
+    *Ulysse Buonomo*
+
+*   Change `QueryMethods#in_order_of` to drop records not listed in values.
+
+    `in_order_of` now filters down to the values provided, to match the behavior of the `Enumerable` version.
+
+    *Kevin Newton*
+
+*   Allow named expression indexes to be revertible.
+
+    Previously, the following code would raise an error in a reversible migration executed while rolling back, due to the index name not being used in the index removal.
+
+    ```ruby
+    add_index(:settings, "(data->'property')", using: :gin, name: :index_settings_data_property)
+    ```
+
+    Fixes #43331.
+
+    *Oliver Günther*
+
+*   Fix incorrect argument in PostgreSQL structure dump tasks.
+
+    Updating the `--no-comment` argument added in Rails 7 to the correct `--no-comments` argument.
+
+    *Alex Dent*
+
+*   Fix migration compatibility to create SQLite references/belongs_to column as integer when migration version is 6.0.
+
+    Reference/belongs_to in migrations with version 6.0 were creating columns as
+    bigint instead of integer for the SQLite Adapter.
+
+    *Marcelo Lauxen*
+
+*   Add a deprecation warning when `prepared_statements` configuration is not
+    set for the mysql2 adapter.
+
+    *Thiago Araujo and Stefanni Brasil*
+
+*   Fix `QueryMethods#in_order_of` to handle empty order list.
+
+    ```ruby
+    Post.in_order_of(:id, []).to_a
+    ```
+
+    Also more explicitly set the column as secondary order, so that any other
+    value is still ordered.
+
+    *Jean Boussier*
+
+*   Fix quoting of column aliases generated by calculation methods.
+
+    Since the alias is derived from the table name, we can't assume the result
+    is a valid identifier.
+
+    ```ruby
+    class Test < ActiveRecord::Base
+      self.table_name = '1abc'
+    end
+    Test.group(:id).count
+    # syntax error at or near "1" (ActiveRecord::StatementInvalid)
+    # LINE 1: SELECT COUNT(*) AS count_all, "1abc"."id" AS 1abc_id FROM "1...
+    ```
+
+    *Jean Boussier*
+
+*   Add `authenticate_by` when using `has_secure_password`.
+
+    `authenticate_by` is intended to replace code like the following, which
+    returns early when a user with a matching email is not found:
+
+    ```ruby
+    User.find_by(email: "...")&.authenticate("...")
+    ```
+
+    Such code is vulnerable to timing-based enumeration attacks, wherein an
+    attacker can determine if a user account with a given email exists. After
+    confirming that an account exists, the attacker can try passwords associated
+    with that email address from other leaked databases, in case the user
+    re-used a password across multiple sites (a common practice). Additionally,
+    knowing an account email address allows the attacker to attempt a targeted
+    phishing ("spear phishing") attack.
+
+    `authenticate_by` addresses the vulnerability by taking the same amount of
+    time regardless of whether a user with a matching email is found:
+
+    ```ruby
+    User.authenticate_by(email: "...", password: "...")
+    ```
+
+    *Jonathan Hefner*
+
+
+Please check [7-0-stable](https://github.com/rails/rails/blob/7-0-stable/activerecord/CHANGELOG.md) for previous changes.
diff --git a/tools/rail_inspector/test/fixtures/active_support_9f0b8eb.md b/tools/rail_inspector/test/fixtures/active_support_9f0b8eb.md
new file mode 100644
index 00000000000..b3aa9dca3d0
--- /dev/null
+++ b/tools/rail_inspector/test/fixtures/active_support_9f0b8eb.md
@@ -0,0 +1,152 @@
+*   Fix `NoMethodError` on custom `ActiveSupport::Deprecation` behavior.
+
+    `ActiveSupport::Deprecation.behavior=` was supposed to accept any object
+    that responds to `call`, but in fact its internal implementation assumed that
+    this object could respond to `arity`, so it was restricted to only `Proc` objects.
+
+    This change removes this `arity` restriction of custom behaviors.
+
+    *Ryo Nakamura*
+
+*   Support `:url_safe` option for `MessageEncryptor`.
+
+    The `MessageEncryptor` constructor now accepts a `:url_safe` option, similar
+    to the `MessageVerifier` constructor.  When enabled, this option ensures
+    that messages use a URL-safe encoding.
+
+    *Jonathan Hefner*
+
+*   Add `url_safe` option to `ActiveSupport::MessageVerifier` initializer
+
+    `ActiveSupport::MessageVerifier.new` now takes optional `url_safe` argument.
+    It can generate URL-safe strings by passing `url_safe: true`.
+
+    ```ruby
+    verifier = ActiveSupport::MessageVerifier.new(url_safe: true)
+    message = verifier.generate(data) # => URL-safe string
+    ```
+
+    This option is `false` by default to be backwards compatible.
+
+    *Shouichi Kamiya*
+
+*   Enable connection pooling by default for `MemCacheStore` and `RedisCacheStore`.
+
+    If you want to disable connection pooling, set `:pool` option to `false` when configuring the cache store:
+
+    ```ruby
+    config.cache_store = :mem_cache_store, "cache.example.com", pool: false
+    ```
+
+    *fatkodima*
+
+*   Add `force:` support to `ActiveSupport::Cache::Store#fetch_multi`.
+
+    *fatkodima*
+
+*   Deprecated `:pool_size` and `:pool_timeout` options for configuring connection pooling in cache stores.
+
+    Use `pool: true` to enable pooling with default settings:
+
+    ```ruby
+    config.cache_store = :redis_cache_store, pool: true
+    ```
+
+    Or pass individual options via `:pool` option:
+
+    ```ruby
+    config.cache_store = :redis_cache_store, pool: { size: 10, timeout: 2 }
+    ```
+
+    *fatkodima*
+
+*   Allow #increment and #decrement methods of `ActiveSupport::Cache::Store`
+    subclasses to set new values.
+
+    Previously incrementing or decrementing an unset key would fail and return
+    nil. A default will now be assumed and the key will be created.
+
+    *Andrej Blagojević*, *Eugene Kenny*
+
+*   Add `skip_nil:` support to `RedisCacheStore`
+
+    *Joey Paris*
+
+*   `ActiveSupport::Cache::MemoryStore#write(name, val, unless_exist:true)` now
+    correctly writes expired keys.
+
+    *Alan Savage*
+
+*   `ActiveSupport::ErrorReporter` now accepts and forward a `source:` parameter.
+
+    This allow libraries to signal the origin of the errors, and reporters
+    to easily ignore some sources.
+
+    *Jean Boussier*
+
+*   Fix and add protections for XSS in `ActionView::Helpers` and `ERB::Util`.
+
+    Add the method `ERB::Util.xml_name_escape` to escape dangerous characters
+    in names of tags and names of attributes, following the specification of XML.
+
+    *Álvaro Martín Fraguas*
+
+*   Respect `ActiveSupport::Logger.new`'s `:formatter` keyword argument
+
+    The stdlib `Logger::new` allows passing a `:formatter` keyword argument to
+    set the logger's formatter. Previously `ActiveSupport::Logger.new` ignored
+    that argument by always setting the formatter to an instance of
+    `ActiveSupport::Logger::SimpleFormatter`.
+
+    *Steven Harman*
+
+*   Deprecate preserving the pre-Ruby 2.4 behavior of `to_time`
+
+    With Ruby 2.4+ the default for +to_time+ changed from converting to the
+    local system time to preserving the offset of the receiver. At the time Rails
+    supported older versions of Ruby so a compatibility layer was added to assist
+    in the migration process. From Rails 5.0 new applications have defaulted to
+    the Ruby 2.4+ behavior and since Rails 7.0 now only supports Ruby 2.7+
+    this compatibility layer can be safely removed.
+
+    To minimize any noise generated the deprecation warning only appears when the
+    setting is configured to `false` as that is the only scenario where the
+    removal of the compatibility layer has any effect.
+
+    *Andrew White*
+
+*   `Pathname.blank?` only returns true for `Pathname.new("")`
+
+    Previously it would end up calling `Pathname#empty?` which returned true
+    if the path existed and was an empty directory or file.
+
+    That behavior was unlikely to be expected.
+
+    *Jean Boussier*
+
+*   Deprecate `Notification::Event`'s `#children` and `#parent_of?`
+
+*   Change default serialization format of `MessageEncryptor` from `Marshal` to `JSON` for Rails 7.1.
+
+    Existing apps are provided with an upgrade path to migrate to `JSON` as described in `guides/source/upgrading_ruby_on_rails.md`
+
+    *Zack Deveau* and *Martin Gingras*
+
+*   Add `ActiveSupport::TestCase#stub_const` to stub a constant for the duration of a yield.
+
+    *DHH*
+
+*   Fix `ActiveSupport::EncryptedConfiguration` to be compatible with Psych 4
+
+    *Stephen Sugden*
+
+*   Improve `File.atomic_write` error handling
+
+*   Fix `Class#descendants` and `DescendantsTracker#descendants` compatibility with Ruby 3.1.
+
+    [The native `Class#descendants` was reverted prior to Ruby 3.1 release](https://bugs.ruby-lang.org/issues/14394#note-33),
+    but `Class#subclasses` was kept, breaking the feature detection.
+
+    *Jean Boussier*
+
+Please check [7-0-stable](https://github.com/rails/rails/blob/7-0-stable/activesupport/CHANGELOG.md) for previous changes.
diff --git a/tools/rail_inspector/test/fixtures/railties_06e9fbd.md b/tools/rail_inspector/test/fixtures/railties_06e9fbd.md
new file mode 100644
index 00000000000..b85eb486caf
--- /dev/null
+++ b/tools/rail_inspector/test/fixtures/railties_06e9fbd.md
@@ -0,0 +1,215 @@
+*   In-app custom credentials templates are now supported.  When a credentials
+    file does not exist, `rails credentials:edit` will now try to use
+    `lib/templates/rails/credentials/credentials.yml.tt` to generate the
+    credentials file, before falling back to the default template.
+
+    This allows e.g. an open-source Rails app (which would not include encrypted
+    credentials files in its repo) to include a credentials template, so that
+    users who install the app will get a custom pre-filled credentials file when
+    they run `rails credentials:edit`.
+
+    *Jonathan Hefner*
+
+*   Except for `dev` and `test` environments, newly generated per-environment
+    credentials files (e.g. `config/credentials/production.yml.enc`) now include
+    a `secret_key_base` for convenience, just as `config/credentials.yml.enc`
+    does.
+
+    *Jonathan Hefner*
+
+*   `--no-*` options now work with the app generator's `--minimal` option, and
+    are both comprehensive and precise.  For example:
+
+    ```console
+    $ rails new my_cool_app --minimal
+    Based on the specified options, the following options will also be activated:
+
+      --skip-active-job [due to --minimal]
+      --skip-action-mailer [due to --skip-active-job, --minimal]
+      --skip-active-storage [due to --skip-active-job, --minimal]
+      --skip-action-mailbox [due to --skip-active-storage, --minimal]
+      --skip-action-text [due to --skip-active-storage, --minimal]
+      --skip-javascript [due to --minimal]
+      --skip-hotwire [due to --skip-javascript, --minimal]
+      --skip-action-cable [due to --minimal]
+      --skip-bootsnap [due to --minimal]
+      --skip-dev-gems [due to --minimal]
+      --skip-system-test [due to --minimal]
+
+    ...
+
+    $ rails new my_cool_app --minimal --no-skip-active-storage
+    Based on the specified options, the following options will also be activated:
+
+      --skip-action-mailer [due to --minimal]
+      --skip-action-mailbox [due to --minimal]
+      --skip-action-text [due to --minimal]
+      --skip-javascript [due to --minimal]
+      --skip-hotwire [due to --skip-javascript, --minimal]
+      --skip-action-cable [due to --minimal]
+      --skip-bootsnap [due to --minimal]
+      --skip-dev-gems [due to --minimal]
+      --skip-system-test [due to --minimal]
+
+    ...
+    ```
+
+    *Brad Trick* and *Jonathan Hefner*
+
+*   Add `--skip-dev-gems` option to app generator to skip adding development
+    gems (like `web-console`) to the Gemfile.
+
+    *Brad Trick*
+
+*   Skip Active Storage and Action Mailer if Active Job is skipped.
+
+    *Étienne Barrié*
+
+*   Correctly check if frameworks are disabled when running app:update.
+
+    *Étienne Barrié* and *Paulo Barros*
+
+*   Delegate model generator description to orm hooked generator.
+
+    *Gannon McGibbon*
+
+*   Execute `rails runner` scripts inside the executor.
+
+    Enables error reporting, query cache, etc.
+
+    *Jean Boussier*
+
+*   Avoid booting in development then test for test tasks.
+
+    Running one of the rails test subtasks (e.g. test:system, test:models) would
+    go through Rake and cause the app to be booted twice. Now all the test:*
+    subtasks are defined as Thor tasks and directly load the test environment.
+
+    *Étienne Barrié*
+
+*   Deprecate `Rails::Generators::Testing::Behaviour` in favor of `Rails::Generators::Testing::Behavior`.
+
+    *Gannon McGibbon*
+
+*   Allow configuration of logger size for local and test environments
+
+    `config.log_file_size`
+
+    Defaults to `100` megabytes.
+
+    *Bernie Chiu*
+
+*   Enroll new apps in decrypted diffs of credentials by default.  This behavior
+    can be opted out of with the app generator's `--skip-decrypted-diffs` flag.
+
+    *Jonathan Hefner*
+
+*   Support declarative-style test name filters with `bin/rails test`.
+
+    This makes it possible to run a declarative-style test such as:
+
+    ```ruby
+    class MyTest < ActiveSupport::TestCase
+      test "does something" do
+        # ...
+      end
+    end
+    ```
+
+    Using its declared name:
+
+    ```bash
+    $ bin/rails test test/my_test.rb -n "does something"
+    ```
+
+    Instead of having to specify its expanded method name:
+
+    ```bash
+    $ bin/rails test test/my_test.rb -n test_does_something
+    ```
+
+    *Jonathan Hefner*
+
+*   Add `--js` and `--skip-javascript` options to `rails new`
+
+    `--js` alias to `rails new --javascript ...`
+
+    Same as `-j`, e.g. `rails new --js esbuild ...`
+
+    `--skip-js` alias to `rails new --skip-javascript ...`
+
+    Same as `-J`, e.g. `rails new --skip-js ...`
+
+    *Dorian Marié*
+
+*   Allow relative paths with leading dot slash to be passed to `rails test`.
+
+    Fix `rails test ./test/model/post_test.rb` to run a single test file.
+
+    *Shouichi Kamiya* and *oljfte*
+
+*   Deprecate `config.enable_dependency_loading`. This flag addressed a limitation of the `classic` autoloader and has no effect nowadays. To fix this deprecation, please just delete the reference.
+
+    *Xavier Noria*
+
+*   Define `config.enable_reloading` to be `!config.cache_classes` for a more intuitive name. While `config.enable_reloading` and `config.reloading_enabled?` are preferred from now on, `config.cache_classes` is supported for backwards compatibility.
+
+    *Xavier Noria*
+
+*   Add JavaScript dependencies installation on bin/setup
+
+    Add  `yarn install` to bin/setup when using esbuild, webpack, or rollout.
+
+    *Carlos Ribeiro*
+
+*   Use `controller_class_path` in `Rails::Generators::NamedBase#route_url`
+
+    The `route_url` method now returns the correct path when generating
+    a namespaced controller with a top-level model using `--model-name`.
+
+    Previously, when running this command:
+
+    ``` sh
+    bin/rails generate scaffold_controller Admin/Post --model-name Post
+    ```
+
+    the comments above the controller action would look like:
+
+    ``` ruby
+    # GET /posts
+    def index
+      @posts = Post.all
+    end
+    ```
+
+    afterwards, they now look like this:
+
+    ``` ruby
+    # GET /admin/posts
+    def index
+      @posts = Post.all
+    end
+    ```
+
+    Fixes #44662.
+
+    *Andrew White*
+
+*   No longer add autoloaded paths to `$LOAD_PATH`.
+
+    This means it won't be possible to load them with a manual `require` call, the class or module can be referenced instead.
+
+    Reducing the size of `$LOAD_PATH` speed-up `require` calls for apps not using `bootsnap`, and reduce the
+    size of the `bootsnap` cache for the others.
+
+    *Jean Boussier*
+
+*   Remove default `X-Download-Options` header
+
+    This header is currently only used by Internet Explorer which
+    will be discontinued in 2022 and since Rails 7 does not fully
+    support Internet Explorer this header should not be a default one.
+
+    *Harun Sabljaković*
+
+Please check [7-0-stable](https://github.com/rails/rails/blob/7-0-stable/railties/CHANGELOG.md) for previous changes.
diff --git a/tools/rail_inspector/test/rail_inspector/changelog_test.rb b/tools/rail_inspector/test/rail_inspector/changelog_test.rb
new file mode 100644
index 00000000000..1458709d44f
--- /dev/null
+++ b/tools/rail_inspector/test/rail_inspector/changelog_test.rb
@@ -0,0 +1,147 @@
+# frozen_string_literal: true
+
+require "rail_inspector/changelog"
+require "test/test_helpers/changelog_fixtures"
+
+class TestChangelog < Minitest::Test
+  include ChangelogFixtures
+
+  def test_parses_changelog_file
+    @changelog = changelog_fixture("railties_06e9fbd.md")
+
+    assert_equal 21, entries.length
+  end
+
+  def test_entries_without_author_are_invalid
+    @changelog = changelog_fixture("active_support_9f0b8eb.md")
+
+    assert_equal 2, offenses.length
+  end
+
+  def test_parses_with_extra_newlines
+    @changelog = changelog_fixture("action_mailbox_83d85b2.md")
+
+    assert_equal 0, entries.length
+  end
+
+  def test_entries_with_trailing_whitespace_are_invalid
+    @changelog = changelog_fixture("active_record_936a862.md")
+
+    assert_equal 16, offenses.length
+  end
+
+  def test_entries_without_four_leading_spaces
+    @changelog = changelog_fixture("active_record_238432d.md")
+
+    assert_equal 5, offenses.length
+  end
+
+  def test_entries_with_incorrectly_indented_header
+    @changelog = changelog_fixture("active_record_51852d2.md")
+
+    assert_equal 1, offenses.length
+  end
+
+  def test_header_ending_with_star_not_treated_as_author
+    @changelog = changelog_fixture("action_pack_69d504.md")
+
+    assert_equal 0, offenses.length
+  end
+
+  def test_validate_authors
+    assert_offense(<<~CHANGELOG)
+      *   Fix issue in CHANGELOG linting
+      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ CHANGELOG entry is missing authors.
+    CHANGELOG
+  end
+
+  def test_validate_leading_whitespace_for_header
+    assert_offense(<<~CHANGELOG)
+      * Fix leading whitespace in CHANGELOG
+      ^^^^ CHANGELOG header must start with '*' and 3 spaces
+
+          *Hartley McGuire*
+    CHANGELOG
+
+    assert_offense(<<~CHANGELOG)
+      *    Fix leading whitespace in CHANGELOG
+      ^^^^ CHANGELOG header must start with '*' and 3 spaces
+
+          *Hartley McGuire*
+    CHANGELOG
+  end
+
+  def test_validate_leading_whitespace_for_body
+    assert_offense(<<~CHANGELOG)
+      *   Fix leading whitespace in CHANGELOG
+
+        *Hartley McGuire*
+      ^^^^ CHANGELOG line must be indented 4 spaces
+    CHANGELOG
+  end
+
+  def test_validate_trailing_whitespace
+    assert_offense(<<~CHANGELOG)
+      *   Fix trailing whitespace in CHANGELOG#{' '}
+                                              ^ Trailing whitespace detected.
+
+          *Hartley McGuire*
+    CHANGELOG
+
+    assert_offense(<<~CHANGELOG)
+      *   Fix trailing whitespace in CHANGELOG
+      #{' '}
+      ^ Trailing whitespace detected.
+          *Hartley McGuire*
+    CHANGELOG
+  end
+
+  private
+    def entries
+      @changelog.entries
+    end
+
+    def offenses
+      entries.flat_map(&:offenses)
+    end
+
+    ANNOTATION_PATTERN = /\s*\^+ /
+
+    def assert_offense(source)
+      lines = []
+      annotation = nil
+
+      source.each_line(chomp: true) do |line|
+        if ANNOTATION_PATTERN.match?(line)
+          annotation = [lines.length, line]
+        else
+          lines << line
+        end
+      end
+
+      entry = RailInspector::Changelog::Entry.new(lines, 1)
+
+      assert_equal 1,
+                   entry.offenses.length,
+                   "Entry has the wrong number of offenses"
+      offense = entry.offenses.first
+
+      assert_equal annotation[0],
+                   offense.line_number,
+                   "Offense has incorrect line number"
+      assert_equal lines[annotation[0] - 1],
+                   offense.line,
+                   "Offense has incorrect line"
+
+      annotation_message = annotation[1].gsub(ANNOTATION_PATTERN, "")
+      assert_equal annotation_message,
+                   offense.message,
+                   "Offense has incorrect message"
+
+      annotation_start = annotation[1].index("^") + 1
+      annotation_end = annotation[1].rindex("^") + 1
+      assert_equal annotation_start..annotation_end,
+                   offense.range,
+                   "Offense has incorrect range"
+    end
+end
diff --git a/tools/rail_inspector/test/rail_inspector/visitor/framework_default_test.rb b/tools/rail_inspector/test/rail_inspector/visitor/framework_default_test.rb
new file mode 100644
index 00000000000..b1497d69f08
--- /dev/null
+++ b/tools/rail_inspector/test/rail_inspector/visitor/framework_default_test.rb
@@ -0,0 +1,105 @@
+# frozen_string_literal: true
+
+require "rail_inspector/visitor/framework_default"
+
+class FrameworkDefaultTest < Minitest::Test
+  def test_smoke
+    config = config_for_defaults <<~RUBY
+      case target_version.to_s
+      when "5.0"
+        ActiveSupport.to_time_preserves_timezone = true
+
+        if respond_to?(:active_record)
+          active_record.belongs_to_required_by_default = true
+        end
+
+        self.ssl_options = { hsts: { subdomains: true } }
+      when "5.1"
+        load_defaults "5.0"
+
+        if respond_to?(:assets)
+          assets.unknown_asset_fallback = false
+        end
+      else
+        raise
+      end
+    RUBY
+
+    ["5.0", "5.1"].each { |k| assert_includes(config, k) }
+
+    assert_equal config["5.0"]["ActiveSupport.to_time_preserves_timezone"], "true"
+    assert_equal config["5.0"]["active_record.belongs_to_required_by_default"], "true"
+    assert_equal config["5.0"]["self.ssl_options"], "{ hsts: { subdomains: true } }"
+    assert_equal config["5.1"]["assets.unknown_asset_fallback"], "false"
+  end
+
+  def test_config_wrapped_in_condition
+    config = config_for_defaults <<~RUBY
+      case target_version.to_s
+      when "7.1"
+        if Rails.env.local?
+          self.log_file_size = 100 * 1024 * 1024
+        end
+      end
+    RUBY
+
+    assert_includes config, "7.1"
+    assert_equal config["7.1"]["self.log_file_size"], "100 * 1024 * 1024"
+  end
+
+  def test_condition_inside_framework
+    config = config_for_defaults <<~RUBY
+      case target_version.to_s
+      when "7.1"
+        if respond_to?(:action_view)
+          if Rails::HTML::Sanitizer.html5_support?
+            action_view.sanitizer_vendor = Rails::HTML5::Sanitizer
+          end
+        end
+      end
+    RUBY
+
+    assert_includes config, "7.1"
+    assert_equal config["7.1"]["action_view.sanitizer_vendor"], "Rails::HTML5::Sanitizer"
+  end
+
+  def test_nested_frameworks_raise_when_strict
+    original_env, ENV["STRICT"] = ENV["STRICT"], "true"
+
+    assert_raises do
+      config_for_defaults <<~RUBY
+        case target_version.to_s
+        when "7.1"
+          if respond_to?(:action_view)
+            if respond_to?(:active_record)
+            end
+          end
+        end
+      RUBY
+    end
+  ensure
+    ENV["STRICT"] = original_env
+  end
+
+  private
+    def wrapped_defaults(defaults)
+      <<~RUBY
+      class Configuration
+        def load_defaults(target_version)
+          #{defaults}
+        end
+      end
+      RUBY
+    end
+
+    def config_for_defaults(defaults)
+      full_class = wrapped_defaults(defaults)
+      parsed = SyntaxTree.parse(full_class)
+      visitor.visit(parsed)
+      visitor.config_map
+    end
+
+    def visitor
+      @visitor ||= RailInspector::Visitor::FrameworkDefault.new
+    end
+end
diff --git a/tools/rail_inspector/test/rail_inspector/visitor/hash_to_string_test.rb b/tools/rail_inspector/test/rail_inspector/visitor/hash_to_string_test.rb
new file mode 100644
index 00000000000..8cf20601aaf
--- /dev/null
+++ b/tools/rail_inspector/test/rail_inspector/visitor/hash_to_string_test.rb
@@ -0,0 +1,34 @@
+# frozen_string_literal: true
+
+require "syntax_tree"
+
+require "rail_inspector/visitor/hash_to_string"
+
+class HashToStringTest < Minitest::Test
+  def test_basic_hash_to_s
+    basic_hash = "{ a: 1 }"
+
+    assert_equal basic_hash, string_for(basic_hash)
+  end
+
+  def test_nested_hash_to_s
+    nested_hash = "{ hsts: { subdomains: true } }"
+
+    assert_equal nested_hash, string_for(nested_hash)
+  end
+
+  def test_string_keys_to_s
+    string_keys =
+      '{ "X-Frame-Options" => "SAMEORIGIN", "X-XSS-Protection" => "0", "X-Content-Type-Options" => "nosniff", "X-Permitted-Cross-Domain-Policies" => "none", "Referrer-Policy" => "strict-origin-when-cross-origin" }'
+
+    assert_equal string_keys, string_for(string_keys)
+  end
+
+  private
+    def string_for(hash_as_string)
+      ast = SyntaxTree.parse(hash_as_string)
+      visitor = RailInspector::Visitor::HashToString.new
+      visitor.visit(ast)
+      visitor.to_s
+    end
+end
diff --git a/tools/rail_inspector/test/test_helpers/changelog_fixtures.rb b/tools/rail_inspector/test/test_helpers/changelog_fixtures.rb
new file mode 100644
index 00000000000..5c93c670dd5
--- /dev/null
+++ b/tools/rail_inspector/test/test_helpers/changelog_fixtures.rb
@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+
+require "pathname"
+require "rail_inspector/changelog"
+
+module ChangelogFixtures
+  def changelog_fixture(name)
+    path = Pathname.new(File.expand_path("../fixtures/#{name}", __dir__))
+
+    raise ArgumentError, "#{name} fixture not found" unless path.exist?
+
+    RailInspector::Changelog.new(path, path.read)
+  end
+end
diff --git a/tools/railspect b/tools/railspect
new file mode 100755
index 00000000000..99b6f7e2165
--- /dev/null
+++ b/tools/railspect
@@ -0,0 +1,7 @@
+#!/usr/bin/env ruby
+# frozen_string_literal: true
+
+require "bundler/setup"
+require_relative "rail_inspector/lib/rail_inspector/cli"
+
+RailInspector::Cli.start