Prepare to release RubyGems 3.1.0 final version.

23 files changed, 393 insertions, 142 deletions

diff --git a/lib/rubygems.rb b/lib/rubygems.rb
index 474734bd40..6be55a0379 100644
--- a/lib/rubygems.rb
+++ b/lib/rubygems.rb
@@ -160,24 +160,14 @@ module Gem
   ].freeze
 
   ##
-  # Exception classes used in a Gem.read_binary +rescue+ statement. Not all of
-  # these are defined in Ruby 1.8.7, hence the need for this convoluted setup.
+  # Exception classes used in a Gem.read_binary +rescue+ statement
 
-  READ_BINARY_ERRORS = begin
-    read_binary_errors = [Errno::EACCES, Errno::EROFS, Errno::ENOSYS]
-    read_binary_errors << Errno::ENOTSUP if Errno.const_defined?(:ENOTSUP)
-    read_binary_errors
-  end.freeze
+  READ_BINARY_ERRORS = [Errno::EACCES, Errno::EROFS, Errno::ENOSYS, Errno::ENOTSUP].freeze
 
   ##
-  # Exception classes used in Gem.write_binary +rescue+ statement. Not all of
-  # these are defined in Ruby 1.8.7.
+  # Exception classes used in Gem.write_binary +rescue+ statement
 
-  WRITE_BINARY_ERRORS = begin
-    write_binary_errors = [Errno::ENOSYS]
-    write_binary_errors << Errno::ENOTSUP if Errno.const_defined?(:ENOTSUP)
-    write_binary_errors
-  end.freeze
+  WRITE_BINARY_ERRORS = [Errno::ENOSYS, Errno::ENOTSUP].freeze
 
   @@win_platform = nil
 
diff --git a/lib/rubygems/command.rb b/lib/rubygems/command.rb
index ab683f0049..c1e5e13c5a 100644
--- a/lib/rubygems/command.rb
+++ b/lib/rubygems/command.rb
@@ -369,22 +369,44 @@ class Gem::Command
     end
   end
 
-  def deprecate_option(short_name: nil, long_name: nil, version: nil)
-    @deprecated_options[command].merge!({ short_name => { "rg_version_to_expire" => version } }) if short_name
-    @deprecated_options[command].merge!({ long_name  => { "rg_version_to_expire" => version } }) if long_name
+  ##
+  # Mark a command-line option as deprecated, and optionally specify a
+  # deprecation horizon.
+  #
+  # Note that with the current implementation, every version of the option needs
+  # to be explicitly deprecated, so to deprecate an option defined as
+  #
+  #   add_option('-t', '--[no-]test', 'Set test mode') do |value, options|
+  #     # ... stuff ...
+  #   end
+  #
+  # you would need to explicitly add a call to `deprecate_option` for every
+  # version of the option you want to deprecate, like
+  #
+  #   deprecate_option('-t')
+  #   deprecate_option('--test')
+  #   deprecate_option('--no-test')
+
+  def deprecate_option(name, version: nil, extra_msg: nil)
+    @deprecated_options[command].merge!({ name => { "rg_version_to_expire" => version, "extra_msg" => extra_msg } })
   end
 
   def check_deprecated_options(options)
     options.each do |option|
       if option_is_deprecated?(option)
-        version_to_expire = @deprecated_options[command][option]["rg_version_to_expire"]
+        deprecation = @deprecated_options[command][option]
+        version_to_expire = deprecation["rg_version_to_expire"]
 
         deprecate_option_msg = if version_to_expire
-                                 "The \"#{option}\" option has been deprecated and will be removed in Rubygems #{version_to_expire}, its use is discouraged."
+                                 "The \"#{option}\" option has been deprecated and will be removed in Rubygems #{version_to_expire}."
                                else
-                                 "The \"#{option}\" option has been deprecated and will be removed in future versions of Rubygems, its use is discouraged."
+                                 "The \"#{option}\" option has been deprecated and will be removed in future versions of Rubygems."
                                end
 
+        extra_msg = deprecation["extra_msg"]
+
+        deprecate_option_msg += " #{extra_msg}" if extra_msg
+
         alert_warning(deprecate_option_msg)
       end
     end
diff --git a/lib/rubygems/commands/generate_index_command.rb b/lib/rubygems/commands/generate_index_command.rb
index 941637ea9c..6dccdcb946 100644
--- a/lib/rubygems/commands/generate_index_command.rb
+++ b/lib/rubygems/commands/generate_index_command.rb
@@ -25,6 +25,9 @@ class Gem::Commands::GenerateIndexCommand < Gem::Command
       options[:build_modern] = value
     end
 
+    deprecate_option('--modern', version: '4.0', extra_msg: 'Modern indexes (specs, latest_specs, and prerelease_specs) are always generated, so this option is not needed.')
+    deprecate_option('--no-modern', version: '4.0', extra_msg: 'The `--no-modern` option is currently ignored. Modern indexes (specs, latest_specs, and prerelease_specs) are always generated.')
+
     add_option '--update',
                'Update modern indexes with gems added',
                'since the last update' do |value, options|
diff --git a/lib/rubygems/commands/setup_command.rb b/lib/rubygems/commands/setup_command.rb
index 3448fdfb4e..7844e9d199 100644
--- a/lib/rubygems/commands/setup_command.rb
+++ b/lib/rubygems/commands/setup_command.rb
@@ -98,7 +98,7 @@ class Gem::Commands::SetupCommand < Gem::Command
   end
 
   def check_ruby_version
-    required_version = Gem::Requirement.new '>= 1.8.7'
+    required_version = Gem::Requirement.new '>= 2.3.0'
 
     unless required_version.satisfied_by? Gem.ruby_version
       alert_error "Expected Ruby version #{required_version}, is #{Gem.ruby_version}"
diff --git a/lib/rubygems/commands/sources_command.rb b/lib/rubygems/commands/sources_command.rb
index af145fd7b4..feab23237d 100644
--- a/lib/rubygems/commands/sources_command.rb
+++ b/lib/rubygems/commands/sources_command.rb
@@ -43,6 +43,8 @@ class Gem::Commands::SourcesCommand < Gem::Command
 
     source = Gem::Source.new source_uri
 
+    check_typo_squatting(source)
+
     begin
       if Gem.sources.include? source
         say "source #{source_uri} already present in the cache"
@@ -62,6 +64,18 @@ class Gem::Commands::SourcesCommand < Gem::Command
     end
   end
 
+  def check_typo_squatting(source)
+    if source.typo_squatting?("rubygems.org")
+      question = <<-QUESTION.chomp
+#{source.uri.to_s} is too similar to https://rubygems.org
+
+Do you want to add this source?
+      QUESTION
+
+      terminate_interaction 1 unless ask_yes_no question
+    end
+  end
+
   def check_rubygems_https(source_uri) # :nodoc:
     uri = URI source_uri
 
diff --git a/lib/rubygems/core_ext/kernel_warn.rb b/lib/rubygems/core_ext/kernel_warn.rb
index 96da272d66..6ea72b10c3 100644
--- a/lib/rubygems/core_ext/kernel_warn.rb
+++ b/lib/rubygems/core_ext/kernel_warn.rb
@@ -6,13 +6,17 @@ if RUBY_VERSION >= "2.5"
   module Kernel
     path = "#{__dir__}/" # Frames to be skipped start with this path.
 
-    # Suppress "method redefined" warning
-    original_warn = instance_method(:warn)
-    Module.new {define_method(:warn, original_warn)}
-
     original_warn = method(:warn)
 
-    module_function define_method(:warn) {|*messages, **kw|
+    remove_method :warn
+
+    class << self
+
+      remove_method :warn
+
+    end
+
+    define_method(:warn) do |*messages, **kw|
       unless uplevel = kw[:uplevel]
         if Gem.java_platform?
           return original_warn.call(*messages)
@@ -46,6 +50,6 @@ if RUBY_VERSION >= "2.5"
 
       kw[:uplevel] = uplevel
       original_warn.call(*messages, **kw)
-    }
+    end
   end
 end
diff --git a/lib/rubygems/ext/builder.rb b/lib/rubygems/ext/builder.rb
index d91ecd25de..2fc1074d92 100644
--- a/lib/rubygems/ext/builder.rb
+++ b/lib/rubygems/ext/builder.rb
@@ -6,7 +6,6 @@
 #++
 
 require 'rubygems/user_interaction'
-require "open3"
 
 class Gem::Ext::Builder
 
@@ -68,6 +67,7 @@ class Gem::Ext::Builder
       results << "current directory: #{Dir.pwd}"
       results << (command.respond_to?(:shelljoin) ? command.shelljoin : command)
 
+      require "open3"
       output, status = Open3.capture2e(*command)
       if verbose
         puts output
diff --git a/lib/rubygems/remote_fetcher.rb b/lib/rubygems/remote_fetcher.rb
index c399cc9d95..2ed619f1bc 100644
--- a/lib/rubygems/remote_fetcher.rb
+++ b/lib/rubygems/remote_fetcher.rb
@@ -4,6 +4,7 @@ require 'rubygems/request'
 require 'rubygems/request/connection_pools'
 require 'rubygems/s3_uri_signer'
 require 'rubygems/uri_formatter'
+require 'rubygems/uri_parsing'
 require 'rubygems/user_interaction'
 require 'resolv'
 require 'rubygems/deprecate'
@@ -17,12 +18,16 @@ class Gem::RemoteFetcher
   include Gem::UserInteraction
   extend Gem::Deprecate
 
+  include Gem::UriParsing
+
   ##
   # A FetchError exception wraps up the various possible IO and HTTP failures
   # that could happen while downloading from the internet.
 
   class FetchError < Gem::Exception
 
+    include Gem::UriParsing
+
     ##
     # The URI which was being accessed when the exception happened.
 
@@ -30,13 +35,12 @@ class Gem::RemoteFetcher
 
     def initialize(message, uri)
       super message
-      begin
-        uri = URI(uri)
-        uri.password = 'REDACTED' if uri.password
-        @uri = uri.to_s
-      rescue URI::InvalidURIError, ArgumentError
-        @uri = uri
-      end
+
+      uri = parse_uri(uri)
+
+      uri.password = 'REDACTED' if uri.respond_to?(:password) && uri.password
+
+      @uri = uri.to_s
     end
 
     def to_s # :nodoc:
@@ -107,7 +111,7 @@ class Gem::RemoteFetcher
 
     spec, source = found.max_by { |(s,_)| s.version }
 
-    download spec, source.uri.to_s
+    download spec, source.uri
   end
 
   ##
@@ -130,18 +134,7 @@ class Gem::RemoteFetcher
 
     FileUtils.mkdir_p cache_dir rescue nil unless File.exist? cache_dir
 
-    # Always escape URI's to deal with potential spaces and such
-    # It should also be considered that source_uri may already be
-    # a valid URI with escaped characters. e.g. "{DESede}" is encoded
-    # as "%7BDESede%7D". If this is escaped again the percentage
-    # symbols will be escaped.
-    unless source_uri.is_a?(URI::Generic)
-      begin
-        source_uri = URI.parse(source_uri)
-      rescue
-        source_uri = URI.parse(URI::DEFAULT_PARSER.escape(source_uri.to_s))
-      end
-    end
+    source_uri = parse_uri(source_uri)
 
     scheme = source_uri.scheme
 
@@ -159,7 +152,7 @@ class Gem::RemoteFetcher
           remote_gem_path = source_uri + "gems/#{gem_file_name}"
 
           self.cache_update_path remote_gem_path, local_gem_path
-        rescue Gem::RemoteFetcher::FetchError
+        rescue FetchError
           raise if spec.original_platform == spec.platform
 
           alternate_name = "#{spec.original_name}.gem"
@@ -236,7 +229,7 @@ class Gem::RemoteFetcher
       unless location = response['Location']
         raise FetchError.new("redirecting but no redirect location was given", uri)
       end
-      location = URI.parse response['Location']
+      location = parse_uri location
 
       if https?(uri) && !https?(location)
         raise FetchError.new("redirecting to non-https resource: #{location}", uri)
@@ -254,9 +247,7 @@ class Gem::RemoteFetcher
   # Downloads +uri+ and returns it as a String.
 
   def fetch_path(uri, mtime = nil, head = false)
-    uri = URI.parse uri unless URI::Generic === uri
-
-    raise ArgumentError, "bad uri: #{uri}" unless uri
+    uri = parse_uri uri
 
     unless uri.scheme
       raise ArgumentError, "uri scheme is invalid: #{uri.scheme.inspect}"
@@ -268,21 +259,19 @@ class Gem::RemoteFetcher
       begin
         data = Gem::Util.gunzip data
       rescue Zlib::GzipFile::Error
-        raise FetchError.new("server did not return a valid file", uri.to_s)
+        raise FetchError.new("server did not return a valid file", uri)
       end
     end
 
     data
-  rescue FetchError
-    raise
   rescue Timeout::Error
-    raise UnknownHostError.new('timed out', uri.to_s)
+    raise UnknownHostError.new('timed out', uri)
   rescue IOError, SocketError, SystemCallError,
          *(OpenSSL::SSL::SSLError if defined?(OpenSSL)) => e
     if e.message =~ /getaddrinfo/
-      raise UnknownHostError.new('no such name', uri.to_s)
+      raise UnknownHostError.new('no such name', uri)
     else
-      raise FetchError.new("#{e.class}: #{e}", uri.to_s)
+      raise FetchError.new("#{e.class}: #{e}", uri)
     end
   end
 
diff --git a/lib/rubygems/request.rb b/lib/rubygems/request.rb
index 435c7c53cb..b5a14ec34d 100644
--- a/lib/rubygems/request.rb
+++ b/lib/rubygems/request.rb
@@ -19,6 +19,7 @@ class Gem::Request
   end
 
   def self.proxy_uri(proxy) # :nodoc:
+    require "uri"
     case proxy
     when :no_proxy then nil
     when URI::HTTP then proxy
@@ -173,6 +174,7 @@ class Gem::Request
         :no_proxy : get_proxy_from_env('http')
     end
 
+    require "uri"
     uri = URI(Gem::UriFormatter.new(env_proxy).normalize)
 
     if uri and uri.user.nil? and uri.password.nil?
diff --git a/lib/rubygems/source.rb b/lib/rubygems/source.rb
index b0cce5bea5..8572cb1806 100644
--- a/lib/rubygems/source.rb
+++ b/lib/rubygems/source.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 autoload :FileUtils, 'fileutils'
-autoload :URI, 'uri'
 
+require "rubygems/text"
 ##
 # A Source knows how to list and fetch gems from a RubyGems marshal index.
 #
@@ -11,6 +11,7 @@ autoload :URI, 'uri'
 class Gem::Source
 
   include Comparable
+  include Gem::Text
 
   FILES = { # :nodoc:
     :released   => 'specs',
@@ -219,6 +220,11 @@ class Gem::Source
     end
   end
 
+  def typo_squatting?(host, distance_threshold=4)
+    return if @uri.host.nil?
+    levenshtein_distance(@uri.host, host) <= distance_threshold
+  end
+
 end
 
 require 'rubygems/source/git'
diff --git a/lib/rubygems/specification_policy.rb b/lib/rubygems/specification_policy.rb
index 24c1145907..c3c496db9b 100644
--- a/lib/rubygems/specification_policy.rb
+++ b/lib/rubygems/specification_policy.rb
@@ -1,8 +1,6 @@
-require 'delegate'
-require 'uri'
 require 'rubygems/user_interaction'
 
-class Gem::SpecificationPolicy < SimpleDelegator
+class Gem::SpecificationPolicy
 
   include Gem::UserInteraction
 
@@ -25,7 +23,7 @@ class Gem::SpecificationPolicy < SimpleDelegator
   def initialize(specification)
     @warnings = 0
 
-    super(specification)
+    @specification = specification
   end
 
   ##
@@ -51,7 +49,7 @@ class Gem::SpecificationPolicy < SimpleDelegator
 
     validate_require_paths
 
-    keep_only_files_and_directories
+    @specification.keep_only_files_and_directories
 
     validate_non_files
 
@@ -92,6 +90,8 @@ class Gem::SpecificationPolicy < SimpleDelegator
   # Implementation for Specification#validate_metadata
 
   def validate_metadata
+    metadata = @specification.metadata
+
     unless Hash === metadata
       error 'metadata must be a hash'
     end
@@ -130,7 +130,7 @@ class Gem::SpecificationPolicy < SimpleDelegator
 
     error_messages = []
     warning_messages = []
-    dependencies.each do |dep|
+    @specification.dependencies.each do |dep|
       if prev = seen[dep.type][dep.name]
         error_messages << <<-MESSAGE
 duplicate dependency on #{dep}, (#{prev.requirement}) use:
@@ -145,7 +145,7 @@ duplicate dependency on #{dep}, (#{prev.requirement}) use:
       end
 
       warning_messages << "prerelease dependency on #{dep} is not recommended" if
-          prerelease_dep && !version.prerelease?
+          prerelease_dep && !@specification.version.prerelease?
 
       open_ended = dep.requirement.requirements.all? do |op, version|
         not version.prerelease? and (op == '>' or op == '>=')
@@ -190,14 +190,14 @@ duplicate dependency on #{dep}, (#{prev.requirement}) use:
   def validate_permissions
     return if Gem.win_platform?
 
-    files.each do |file|
+    @specification.files.each do |file|
       next unless File.file?(file)
       next if File.stat(file).mode & 0444 == 0444
       warning "#{file} is not world-readable"
     end
 
-    executables.each do |name|
-      exec = File.join bindir, name
+    @specification.executables.each do |name|
+      exec = File.join @specification.bindir, name
       next unless File.file?(exec)
       next if File.stat(exec).executable?
       warning "#{exec} is not executable"
@@ -208,7 +208,7 @@ duplicate dependency on #{dep}, (#{prev.requirement}) use:
 
   def validate_nil_attributes
     nil_attributes = Gem::Specification.non_nil_attributes.select do |attrname|
-      __getobj__.instance_variable_get("@#{attrname}").nil?
+      @specification.instance_variable_get("@#{attrname}").nil?
     end
     return if nil_attributes.empty?
     error "#{nil_attributes.join ', '} must not be nil"
@@ -216,6 +216,9 @@ duplicate dependency on #{dep}, (#{prev.requirement}) use:
 
   def validate_rubygems_version
     return unless packaging
+
+    rubygems_version = @specification.rubygems_version
+
     return if rubygems_version == Gem::VERSION
 
     error "expected RubyGems version #{Gem::VERSION}, was #{rubygems_version}"
@@ -223,13 +226,15 @@ duplicate dependency on #{dep}, (#{prev.requirement}) use:
 
   def validate_required_attributes
     Gem::Specification.required_attributes.each do |symbol|
-      unless send symbol
+      unless @specification.send symbol
         error "missing value for attribute #{symbol}"
       end
     end
   end
 
   def validate_name
+    name = @specification.name
+
     if !name.is_a?(String)
       error "invalid value for attribute name: \"#{name.inspect}\" must be a string"
     elsif name !~ /[a-zA-Z]/
@@ -242,14 +247,15 @@ duplicate dependency on #{dep}, (#{prev.requirement}) use:
   end
 
   def validate_require_paths
-    return unless raw_require_paths.empty?
+    return unless @specification.raw_require_paths.empty?
 
     error 'specification must have at least one require_path'
   end
 
   def validate_non_files
     return unless packaging
-    non_files = files.reject {|x| File.file?(x) || File.symlink?(x)}
+
+    non_files = @specification.files.reject {|x| File.file?(x) || File.symlink?(x)}
 
     unless non_files.empty?
       error "[\"#{non_files.join "\", \""}\"] are not files"
@@ -257,18 +263,22 @@ duplicate dependency on #{dep}, (#{prev.requirement}) use:
   end
 
   def validate_self_inclusion_in_files_list
-    return unless files.include?(file_name)
+    file_name = @specification.file_name
 
-    error "#{full_name} contains itself (#{file_name}), check your files list"
+    return unless @specification.files.include?(file_name)
+
+    error "#{@specification.full_name} contains itself (#{file_name}), check your files list"
   end
 
   def validate_specification_version
-    return if specification_version.is_a?(Integer)
+    return if @specification.specification_version.is_a?(Integer)
 
     error 'specification_version must be an Integer (did you mean version?)'
   end
 
   def validate_platform
+    platform = @specification.platform
+
     case platform
     when Gem::Platform, Gem::Platform::RUBY  # ok
     else
@@ -283,7 +293,7 @@ duplicate dependency on #{dep}, (#{prev.requirement}) use:
   end
 
   def validate_array_attribute(field)
-    val = self.send(field)
+    val = @specification.send(field)
     klass = case field
             when :dependencies then
               Gem::Dependency
@@ -298,12 +308,14 @@ duplicate dependency on #{dep}, (#{prev.requirement}) use:
   end
 
   def validate_authors_field
-    return unless authors.empty?
+    return unless @specification.authors.empty?
 
     error "authors may not be empty"
   end
 
   def validate_licenses
+    licenses = @specification.licenses
+
     licenses.each do |license|
       if license.length > 64
         error "each license must be 64 characters or less"
@@ -331,24 +343,27 @@ http://spdx.org/licenses or '#{Gem::Licenses::NONSTANDARD}' for a nonstandard li
   HOMEPAGE_URI_PATTERN = /\A[a-z][a-z\d+.-]*:/i.freeze
 
   def validate_lazy_metadata
-    unless authors.grep(LAZY_PATTERN).empty?
+    unless @specification.authors.grep(LAZY_PATTERN).empty?
       error "#{LAZY} is not an author"
     end
 
-    unless Array(email).grep(LAZY_PATTERN).empty?
+    unless Array(@specification.email).grep(LAZY_PATTERN).empty?
       error "#{LAZY} is not an email"
     end
 
-    if description =~ LAZY_PATTERN
+    if @specification.description =~ LAZY_PATTERN
       error "#{LAZY} is not a description"
     end
 
-    if summary =~ LAZY_PATTERN
+    if @specification.summary =~ LAZY_PATTERN
       error "#{LAZY} is not a summary"
     end
 
+    homepage = @specification.homepage
+
     # Make sure a homepage is valid HTTP/HTTPS URI
     if homepage and not homepage.empty?
+      require 'uri'
       begin
         homepage_uri = URI.parse(homepage)
         unless [URI::HTTP, URI::HTTPS].member? homepage_uri.class
@@ -365,29 +380,29 @@ http://spdx.org/licenses or '#{Gem::Licenses::NONSTANDARD}' for a nonstandard li
       validate_attribute_present(attribute)
     end
 
-    if description == summary
+    if @specification.description == @specification.summary
       warning "description and summary are identical"
     end
 
     # TODO: raise at some given date
-    warning "deprecated autorequire specified" if autorequire
+    warning "deprecated autorequire specified" if @specification.autorequire
 
-    executables.each do |executable|
+    @specification.executables.each do |executable|
       validate_shebang_line_in(executable)
     end
 
-    files.select { |f| File.symlink?(f) }.each do |file|
+    @specification.files.select { |f| File.symlink?(f) }.each do |file|
       warning "#{file} is a symlink, which is not supported on all platforms"
     end
   end
 
   def validate_attribute_present(attribute)
-    value = self.send attribute
+    value = @specification.send attribute
     warning("no #{attribute} specified") if value.nil? || value.empty?
   end
 
   def validate_shebang_line_in(executable)
-    executable_path = File.join(bindir, executable)
+    executable_path = File.join(@specification.bindir, executable)
     return if File.read(executable_path, 2) == '#!'
 
     warning "#{executable_path} is missing #! line"
diff --git a/lib/rubygems/uri_formatter.rb b/lib/rubygems/uri_formatter.rb
index 0a24dde24d..f3d510470b 100644
--- a/lib/rubygems/uri_formatter.rb
+++ b/lib/rubygems/uri_formatter.rb
@@ -1,6 +1,5 @@
 # frozen_string_literal: true
 require 'cgi'
-require 'uri'
 
 ##
 # The UriFormatter handles URIs from user-input and escaping.
diff --git a/lib/rubygems/uri_parser.rb b/lib/rubygems/uri_parser.rb
new file mode 100644
index 0000000000..5c7cabc436
--- /dev/null
+++ b/lib/rubygems/uri_parser.rb
@@ -0,0 +1,36 @@
+# frozen_string_literal: true
+
+##
+# The UriParser handles parsing URIs.
+#
+
+class Gem::UriParser
+
+  ##
+  # Parses the #uri, raising if it's invalid
+
+  def parse!(uri)
+    raise URI::InvalidURIError unless uri
+
+    # Always escape URI's to deal with potential spaces and such
+    # It should also be considered that source_uri may already be
+    # a valid URI with escaped characters. e.g. "{DESede}" is encoded
+    # as "%7BDESede%7D". If this is escaped again the percentage
+    # symbols will be escaped.
+    begin
+      URI.parse(uri)
+    rescue URI::InvalidURIError
+      URI.parse(URI::DEFAULT_PARSER.escape(uri))
+    end
+  end
+
+  ##
+  # Parses the #uri, returning the original uri if it's invalid
+
+  def parse(uri)
+    parse!(uri)
+  rescue URI::InvalidURIError
+    uri
+  end
+
+end
diff --git a/lib/rubygems/uri_parsing.rb b/lib/rubygems/uri_parsing.rb
new file mode 100644
index 0000000000..941d7e023a
--- /dev/null
+++ b/lib/rubygems/uri_parsing.rb
@@ -0,0 +1,23 @@
+# frozen_string_literal: true
+
+require "rubygems/uri_parser"
+
+module Gem::UriParsing
+
+  def parse_uri(source_uri)
+    return source_uri unless source_uri.is_a?(String)
+
+    uri_parser.parse(source_uri)
+  end
+
+  private :parse_uri
+
+  def uri_parser
+    require "uri"
+
+    Gem::UriParser.new
+  end
+
+  private :uri_parser
+
+end
diff --git a/test/rubygems/test_gem_command.rb b/test/rubygems/test_gem_command.rb
index d51371301e..230baa5356 100644
--- a/test/rubygems/test_gem_command.rb
+++ b/test/rubygems/test_gem_command.rb
@@ -197,9 +197,9 @@ class TestGemCommand < Gem::TestCase
     assert_equal ['-h', 'command'], args
   end
 
-  def test_deprecate_option_long_name
+  def test_deprecate_option
     deprecate_msg = <<-EXPECTED
-WARNING:  The \"--test\" option has been deprecated and will be removed in Rubygems 3.1, its use is discouraged.
+WARNING:  The \"--test\" option has been deprecated and will be removed in Rubygems 3.1.
     EXPECTED
 
     testCommand = Class.new(Gem::Command) do
@@ -210,7 +210,7 @@ WARNING:  The \"--test\" option has been deprecated and will be removed in Rubyg
           options[:test] = true
         end
 
-        deprecate_option(long_name: '--test', version: '3.1')
+        deprecate_option('--test', version: '3.1')
       end
 
       def execute
@@ -228,7 +228,7 @@ WARNING:  The \"--test\" option has been deprecated and will be removed in Rubyg
 
   def test_deprecate_option_no_version
     deprecate_msg = <<-EXPECTED
-WARNING:  The \"--test\" option has been deprecated and will be removed in future versions of Rubygems, its use is discouraged.
+WARNING:  The \"--test\" option has been deprecated and will be removed in future versions of Rubygems.
     EXPECTED
 
     testCommand = Class.new(Gem::Command) do
@@ -239,7 +239,7 @@ WARNING:  The \"--test\" option has been deprecated and will be removed in futur
           options[:test] = true
         end
 
-        deprecate_option(long_name: '--test')
+        deprecate_option('--test')
       end
 
       def execute
@@ -255,9 +255,9 @@ WARNING:  The \"--test\" option has been deprecated and will be removed in futur
     end
   end
 
-  def test_deprecate_option_short_name
+  def test_deprecate_option_extra_message
     deprecate_msg = <<-EXPECTED
-WARNING:  The \"-t\" option has been deprecated and will be removed in Rubygems 3.5, its use is discouraged.
+WARNING:  The \"--test\" option has been deprecated and will be removed in Rubygems 3.1. Whether you set `--test` mode or not, this dummy app always runs in test mode.
     EXPECTED
 
     testCommand = Class.new(Gem::Command) do
@@ -268,7 +268,7 @@ WARNING:  The \"-t\" option has been deprecated and will be removed in Rubygems
           options[:test] = true
         end
 
-        deprecate_option(short_name: '-t', version: '3.5')
+        deprecate_option('--test', version: '3.1', extra_msg: 'Whether you set `--test` mode or not, this dummy app always runs in test mode.')
       end
 
       def execute
@@ -279,7 +279,36 @@ WARNING:  The \"-t\" option has been deprecated and will be removed in Rubygems
     cmd = testCommand.new
 
     use_ui @ui do
-      cmd.invoke("-t")
+      cmd.invoke("--test")
+      assert_equal deprecate_msg, @ui.error
+    end
+  end
+
+  def test_deprecate_option_extra_message_and_no_version
+    deprecate_msg = <<-EXPECTED
+WARNING:  The \"--test\" option has been deprecated and will be removed in future versions of Rubygems. Whether you set `--test` mode or not, this dummy app always runs in test mode.
+    EXPECTED
+
+    testCommand = Class.new(Gem::Command) do
+      def initialize
+        super('test', 'Gem::Command instance for testing')
+
+        add_option('-t', '--test', 'Test command') do |value, options|
+          options[:test] = true
+        end
+
+        deprecate_option('--test', extra_msg: 'Whether you set `--test` mode or not, this dummy app always runs in test mode.')
+      end
+
+      def execute
+        true
+      end
+    end
+
+    cmd = testCommand.new
+
+    use_ui @ui do
+      cmd.invoke("--test")
       assert_equal deprecate_msg, @ui.error
     end
   end
diff --git a/test/rubygems/test_gem_commands_generate_index_command.rb b/test/rubygems/test_gem_commands_generate_index_command.rb
index b4276702f4..d8fda32fc0 100644
--- a/test/rubygems/test_gem_commands_generate_index_command.rb
+++ b/test/rubygems/test_gem_commands_generate_index_command.rb
@@ -3,6 +3,10 @@ require 'rubygems/test_case'
 require 'rubygems/indexer'
 require 'rubygems/commands/generate_index_command'
 
+unless defined?(Builder::XChar)
+  warn "generate_index tests are being skipped.  Install builder gem."
+end
+
 class TestGemCommandsGenerateIndexCommand < Gem::TestCase
 
   def setup
@@ -22,6 +26,18 @@ class TestGemCommandsGenerateIndexCommand < Gem::TestCase
     assert File.exist?(specs), specs
   end
 
+  def test_execute_no_modern
+    @cmd.options[:modern] = false
+
+    use_ui @ui do
+      @cmd.execute
+    end
+
+    specs = File.join @gemhome, "specs.4.8.gz"
+
+    assert File.exist?(specs), specs
+  end
+
   def test_handle_options_directory
     return if win_platform?
     refute_equal '/nonexistent', @cmd.options[:directory]
@@ -47,4 +63,24 @@ class TestGemCommandsGenerateIndexCommand < Gem::TestCase
     assert @cmd.options[:update]
   end
 
-end if ''.respond_to? :to_xs
+  def test_handle_options_modern
+    use_ui @ui do
+      @cmd.handle_options %w[--modern]
+    end
+
+    assert_equal \
+      "WARNING:  The \"--modern\" option has been deprecated and will be removed in Rubygems 4.0. Modern indexes (specs, latest_specs, and prerelease_specs) are always generated, so this option is not needed.\n",
+      @ui.error
+  end
+
+  def test_handle_options_no_modern
+    use_ui @ui do
+      @cmd.handle_options %w[--no-modern]
+    end
+
+    assert_equal \
+      "WARNING:  The \"--no-modern\" option has been deprecated and will be removed in Rubygems 4.0. The `--no-modern` option is currently ignored. Modern indexes (specs, latest_specs, and prerelease_specs) are always generated.\n",
+      @ui.error
+  end
+
+end if defined?(Builder::XChar)
diff --git a/test/rubygems/test_gem_commands_help_command.rb b/test/rubygems/test_gem_commands_help_command.rb
index 8fcff6b1e7..f2a519775c 100644
--- a/test/rubygems/test_gem_commands_help_command.rb
+++ b/test/rubygems/test_gem_commands_help_command.rb
@@ -4,20 +4,15 @@ require "rubygems/test_case"
 require "rubygems/commands/help_command"
 require "rubygems/package"
 require "rubygems/command_manager"
-require File.expand_path('../rubygems_plugin', __FILE__)
 
 class TestGemCommandsHelpCommand < Gem::TestCase
 
-  # previously this was calc'd in setup, but 1.8.7 had
-  # intermittent failures, but no issues with above require
-  PLUGIN = File.expand_path('../rubygems_plugin.rb', __FILE__)
-
   def setup
     super
 
     @cmd = Gem::Commands::HelpCommand.new
 
-    load PLUGIN unless Gem::Commands.const_defined? :InterruptCommand
+    load File.expand_path('../rubygems_plugin.rb', __FILE__) unless Gem::Commands.const_defined? :InterruptCommand
   end
 
   def test_gem_help_bad
diff --git a/test/rubygems/test_gem_commands_sources_command.rb b/test/rubygems/test_gem_commands_sources_command.rb
index 36e6ee9293..b63fbce81f 100644
--- a/test/rubygems/test_gem_commands_sources_command.rb
+++ b/test/rubygems/test_gem_commands_sources_command.rb
@@ -74,6 +74,80 @@ class TestGemCommandsSourcesCommand < Gem::TestCase
     assert_equal '', @ui.error
   end
 
+  def test_execute_add_allow_typo_squatting_source
+    rubygems_org = "https://rubyems.org"
+
+    spec_fetcher do |fetcher|
+      fetcher.spec("a", 1)
+    end
+
+    specs = Gem::Specification.map do |spec|
+      [spec.name, spec.version, spec.original_platform]
+    end
+
+    specs_dump_gz = StringIO.new
+    Zlib::GzipWriter.wrap(specs_dump_gz) do |io|
+      Marshal.dump(specs, io)
+    end
+
+    @fetcher.data["#{rubygems_org}/specs.#{@marshal_version}.gz"] = specs_dump_gz.string
+    @cmd.handle_options %W[--add #{rubygems_org}]
+    ui = Gem::MockGemUi.new("y")
+
+    use_ui ui do
+      @cmd.execute
+    end
+
+    expected = "https://rubyems.org is too similar to https://rubygems.org\n\nDo you want to add this source? [yn]  https://rubyems.org added to sources\n"
+
+    assert_equal expected, ui.output
+
+    source = Gem::Source.new(rubygems_org)
+    assert Gem.sources.include?(source)
+
+    assert_empty ui.error
+  end
+
+  def test_execute_add_deny_typo_squatting_source
+    rubygems_org = "https://rubyems.org"
+
+    spec_fetcher do |fetcher|
+      fetcher.spec("a", 1)
+    end
+
+    specs = Gem::Specification.map do |spec|
+      [spec.name, spec.version, spec.original_platform]
+    end
+
+    specs_dump_gz = StringIO.new
+    Zlib::GzipWriter.wrap(specs_dump_gz) do |io|
+      Marshal.dump(specs, io)
+    end
+
+    @fetcher.data["#{rubygems_org}/specs.#{@marshal_version}.gz"] =
+      specs_dump_gz.string
+
+    @cmd.handle_options %W[--add #{rubygems_org}]
+
+    ui = Gem::MockGemUi.new("n")
+
+    use_ui ui do
+
+      assert_raises Gem::MockGemUi::TermError do
+        @cmd.execute
+      end
+    end
+
+    expected = "https://rubyems.org is too similar to https://rubygems.org\n\nDo you want to add this source? [yn]  "
+
+    assert_equal expected, ui.output
+
+    source = Gem::Source.new(rubygems_org)
+    refute Gem.sources.include?(source)
+
+    assert_empty ui.error
+  end
+
   def test_execute_add_nonexistent_source
     spec_fetcher
 
diff --git a/test/rubygems/test_gem_gem_runner.rb b/test/rubygems/test_gem_gem_runner.rb
index 7c771de9e5..0c801847b0 100644
--- a/test/rubygems/test_gem_gem_runner.rb
+++ b/test/rubygems/test_gem_gem_runner.rb
@@ -1,6 +1,5 @@
 # frozen_string_literal: true
 require 'rubygems/test_case'
-require 'rubygems/gem_runner'
 
 class TestGemGemRunner < Gem::TestCase
 
@@ -8,6 +7,8 @@ class TestGemGemRunner < Gem::TestCase
     super
 
     @orig_args = Gem::Command.build_args
+
+    require 'rubygems/gem_runner'
     @runner = Gem::GemRunner.new
   end
 
diff --git a/test/rubygems/test_gem_indexer.rb b/test/rubygems/test_gem_indexer.rb
index 43a04c3bb3..fdef33e464 100644
--- a/test/rubygems/test_gem_indexer.rb
+++ b/test/rubygems/test_gem_indexer.rb
@@ -3,7 +3,7 @@ require 'rubygems/test_case'
 require 'rubygems/indexer'
 
 unless defined?(Builder::XChar)
-  warn "Gem::Indexer tests are being skipped.  Install builder gem." if $VERBOSE
+  warn "Gem::Indexer tests are being skipped.  Install builder gem."
 end
 
 class TestGemIndexer < Gem::TestCase
diff --git a/test/rubygems/test_gem_source.rb b/test/rubygems/test_gem_source.rb
index 2ed9fc78e7..30b45ea267 100644
--- a/test/rubygems/test_gem_source.rb
+++ b/test/rubygems/test_gem_source.rb
@@ -235,4 +235,18 @@ class TestGemSource < Gem::TestCase
     refute @source.update_cache?
   end
 
+  def test_typo_squatting
+    rubygems_source = Gem::Source.new("https://rubgems.org")
+    assert rubygems_source.typo_squatting?("rubygems.org")
+    assert rubygems_source.typo_squatting?("rubyagems.org")
+    assert rubygems_source.typo_squatting?("rubyasgems.org")
+    refute rubygems_source.typo_squatting?("rubysertgems.org")
+  end
+
+  def test_typo_squatting_custom_distance_threshold
+    rubygems_source = Gem::Source.new("https://rubgems.org")
+    distance_threshold = 5
+    assert rubygems_source.typo_squatting?("rubysertgems.org", distance_threshold)
+  end
+
 end
diff --git a/test/rubygems/test_remote_fetch_error.rb b/test/rubygems/test_remote_fetch_error.rb
index 780e5e79f7..766086756e 100644
--- a/test/rubygems/test_remote_fetch_error.rb
+++ b/test/rubygems/test_remote_fetch_error.rb
@@ -5,7 +5,7 @@ class TestRemoteFetchError < Gem::TestCase
 
   def test_password_redacted
     error = Gem::RemoteFetcher::FetchError.new('There was an error fetching', 'https://user:secret@gemsource.org')
-    refute_match error.to_s, 'secret'
+    refute_match 'secret', error.to_s
   end
 
   def test_invalid_url
diff --git a/test/rubygems/test_require.rb b/test/rubygems/test_require.rb
index 69df9093c7..aa2675af5d 100644
--- a/test/rubygems/test_require.rb
+++ b/test/rubygems/test_require.rb
@@ -365,19 +365,16 @@ class TestGemRequire < Gem::TestCase
   end
 
   def test_realworld_default_gem
-    begin
-      gem 'json'
-    rescue Gem::MissingSpecError
-      skip "default gems are only available after ruby installation"
-    end
+    testing_ruby_repo = !ENV["GEM_COMMAND"].nil?
+    skip "this test can't work under ruby-core setup" if testing_ruby_repo || java_platform?
 
     cmd = <<-RUBY
       $stderr = $stdout
       require "json"
-      puts Gem.loaded_specs["json"].default_gem?
+      puts Gem.loaded_specs["json"]
     RUBY
     output = Gem::Util.popen(Gem.ruby, "-e", cmd).strip
-    assert_equal "true", output
+    refute_empty output
   end
 
   def test_default_gem_and_normal_gem
@@ -499,36 +496,38 @@ class TestGemRequire < Gem::TestCase
     end
   end
 
-  # uplevel is 2.5+ only and jruby has some issues with it
-  if RUBY_VERSION >= "2.5" && !java_platform?
-    def test_no_kernel_require_in_warn_with_uplevel
-      lib = File.realpath("../../../lib", __FILE__)
-      Dir.mktmpdir("warn_test") do |dir|
-        File.write(dir + "/sub.rb", "warn 'uplevel', 'test', uplevel: 1\n")
-        File.write(dir + "/main.rb", "require 'sub'\n")
-        _, err = capture_subprocess_io do
-          system(@@ruby, "-w", "-rpp", "--disable=gems", "-I", lib, "-C", dir, "-I.", "main.rb")
-        end
-        assert_equal "main.rb:1: warning: uplevel\ntest\n", err
-        _, err = capture_subprocess_io do
-          system(@@ruby, "-w", "-rpp", "--enable=gems", "-I", lib, "-C", dir, "-I.", "main.rb")
+  # uplevel is 2.5+ only
+  if RUBY_VERSION >= "2.5"
+    ["", "Kernel."].each do |prefix|
+      define_method "test_no_kernel_require_in_#{prefix.tr(".", "_")}warn_with_uplevel" do
+        lib = File.realpath("../../../lib", __FILE__)
+        Dir.mktmpdir("warn_test") do |dir|
+          File.write(dir + "/sub.rb", "#{prefix}warn 'uplevel', 'test', uplevel: 1\n")
+          File.write(dir + "/main.rb", "require 'sub'\n")
+          _, err = capture_subprocess_io do
+            system(@@ruby, "-w", "--disable=gems", "-I", lib, "-C", dir, "-I.", "main.rb")
+          end
+          assert_match(/main\.rb:1: warning: uplevel\ntest\n$/, err)
+          _, err = capture_subprocess_io do
+            system(@@ruby, "-w", "--enable=gems", "-I", lib, "-C", dir, "-I.", "main.rb")
+          end
+          assert_match(/main\.rb:1: warning: uplevel\ntest\n$/, err)
         end
-        assert_equal "main.rb:1: warning: uplevel\ntest\n", err
       end
-    end
 
-    def test_no_other_behavioral_changes_with_kernel_warn
-      lib = File.realpath("../../../lib", __FILE__)
-      Dir.mktmpdir("warn_test") do |dir|
-        File.write(dir + "/main.rb", "warn({x:1}, {y:2}, [])\n")
-        _, err = capture_subprocess_io do
-          system(@@ruby, "-w", "-rpp", "--disable=gems", "-I", lib, "-C", dir, "-I.", "main.rb")
-        end
-        assert_equal "{:x=>1}\n{:y=>2}\n", err
-        _, err = capture_subprocess_io do
-          system(@@ruby, "-w", "-rpp", "--enable=gems", "-I", lib, "-C", dir, "-I.", "main.rb")
+      define_method "test_no_other_behavioral_changes_with_#{prefix.tr(".", "_")}warn" do
+        lib = File.realpath("../../../lib", __FILE__)
+        Dir.mktmpdir("warn_test") do |dir|
+          File.write(dir + "/main.rb", "#{prefix}warn({x:1}, {y:2}, [])\n")
+          _, err = capture_subprocess_io do
+            system(@@ruby, "-w", "--disable=gems", "-I", lib, "-C", dir, "main.rb")
+          end
+          assert_match(/{:x=>1}\n{:y=>2}\n$/, err)
+          _, err = capture_subprocess_io do
+            system(@@ruby, "-w", "--enable=gems", "-I", lib, "-C", dir, "main.rb")
+          end
+          assert_match(/{:x=>1}\n{:y=>2}\n$/, err)
         end
-        assert_equal "{:x=>1}\n{:y=>2}\n", err
       end
     end
   end