Improve performance in Ruby 2.4 and later

.travis.yml

@@ -1,11 +1,8 @@
 language: ruby
 rvm:
-  - "2.0.0"
-  - "2.1"
-  - "2.2"
-  - "2.3"
   - "2.4"
   - "2.5"
+  - "2.6"
   - ruby-head
 matrix:
   allow_failures:

Readme.md

@@ -9,7 +9,7 @@ With the help of this gem you can filter out all those useless messages and only
 Add to your Gemfile:
 
 ```ruby
-gem "ruby_warning_filter", "~> 1.0.0"
+gem "ruby_warning_filter", "~> 1.1.0"
 ```
 
 Put the following code somewhere before your project is loaded. In a Rails application, a good place would be at the end of "config/boot.rb".
@@ -28,4 +28,4 @@ The filter works by proxying all writes to stderr. It has been running for a whi
 
 [![Build Status](https://travis-ci.org/semaperepelitsa/ruby_warning_filter.svg?branch=master)](https://travis-ci.org/semaperepelitsa/ruby_warning_filter)
 
-The gem is tested against Ruby versions 2.5 down to 2.0.
+The gem is tested against Ruby 2.6, 2.5, 2.4.

lib/ruby_warning_filter.rb

@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require "delegate"
 require "set"
 
@@ -20,67 +21,51 @@
 #
 class RubyWarningFilter < DelegateClass(IO)
   attr_reader :ruby_warnings
+  BACKTRACE = "\tfrom"
+  RUBY_WARNING = %r{(^<main>|\.bundle|:\d+|:in `\S+'): warning:}
+  EVAL_REDEFINED = /\(eval\):\d+: warning: previous definition of .+ was here/
+
+  # Variables used in tag attributes (Slim) always cause a warning.
+  # TODO: Report this.
+  IGNORED_TEMPLATE_WARNING = %r{\.slim:\d+: warning: possibly useless use of a variable in void context$}
+
+  # The source of this warning cannot be located so we have to ignore it completely
+  # See example: https://github.com/deivid-rodriguez/pry-byebug/issues/221
+  IGNORED_EVAL_WARNING = %r{^<main>(:\d+)?: warning: .+ in eval may not return location in binding; use Binding#source_location instead$}
 
   def initialize(io, ignore_path: Gem.path)
     super(io)
 
     @ruby_warnings = 0
     @ignored = false
-    @ignore_path = ignore_path.to_set
 
     # Gem path can contain symlinks.
     # Some warnings use real path instead of symlinks so we need to ignore both.
-    ignore_path.each do |a|
-      @ignore_path << File.realpath(a) if File.exist?(a)
-    end
+    ignore_full_path = ignore_path + ignore_path.select{ |a| File.exist?(a) }.map{ |a| File.realpath(a) }
+    @ignore_regexp = Regexp.new("^(#{Regexp.union(ignore_full_path).source})")
   end
 
   def write(line)
-    if @ignored && (backtrace?(line) || line == "\n")
+    if @ignored && (line == "\n" || line.start_with?(BACKTRACE))
       # Ignore the whole backtrace after ignored warning.
       # Some warnings write newline separately for some reason.
       @ignored = true
       nil
-    elsif @ignored && eval_redefined?(line)
+    elsif @ignored && EVAL_REDEFINED.match?(line)
       # Some gems use eval to redefine methods and the second warning with the source does not have file path, so we need to ignore that explicitly.
       @ignored = false
       nil
-    elsif ruby_warning?(line)
-      @ignored = ignored_warning?(line)
+    elsif RUBY_WARNING.match?(line)
+      @ignored = IGNORED_TEMPLATE_WARNING.match?(line) ||
+                 IGNORED_EVAL_WARNING.match?(line) ||
+                 @ignore_regexp.match?(line)
       unless @ignored
         @ruby_warnings += 1
         super
       end
     else
+      @ignored = false
       super
     end
   end
-
-  private
-
-  def ruby_warning?(line)
-    line =~ %r{:(\d+|in `\S+'): warning:}
-  end
-
-  def ignored_warning?(line)
-    external_warning?(line) || ignored_template_warning?(line)
-  end
-
-  def external_warning?(line)
-    @ignore_path.any?{ |path| line.start_with?(path) }
-  end
-
-  # Variables used in tag attributes (Slim) always cause a warning.
-  # TODO: Report this.
-  def ignored_template_warning?(line)
-    line =~ %r{\.slim:\d+: warning: possibly useless use of a variable in void context$}
-  end
-
-  def backtrace?(line)
-    line.start_with?("\tfrom")
-  end
-
-  def eval_redefined?(line)
-    line =~ /\(eval\):\d+: warning: previous definition of .+ was here/
-  end
 end

ruby_warning_filter.gemspec

@@ -1,10 +1,11 @@
 Gem::Specification.new do |gem|
   gem.name    = "ruby_warning_filter"
-  gem.version = "1.0.1"
+  gem.version = "1.1.0"
   gem.summary = "Hassle-free Ruby warnings"
   gem.license = "MIT"
-  gem.author  = "Semyon Perepelitsa"
+  gem.author  = "Simon Perepelitsa"
   gem.email   = "sema@sema.in"
+  gem.required_ruby_version = '>= 2.4.0'
 
   gem.homepage = "https://github.com/semaperepelitsa/ruby_warning_filter"
 

test/bench.rb

@@ -10,20 +10,22 @@ def write_errors(io)
     io.write("/path/to/gems/file.rb:297: warning: instance variable @object not initialized\n")
   end
 
-  10.times do |i|
+  7.times do |i|
     io.write("\tfrom /something/foo/bar:#{i}:in  `<main>'")
+    io.write("\n")
   end
 
-  10.times do
+  7.times do
     io.write("(eval):1: warning: previous definition of foo was here")
+    io.write("\n")
   end
 end
 
 
 # Sample results in Ruby 2.3.1:
 #
-#          plain File     80.673k (± 2.5%) i/s -    410.454k in   5.091134s
-#   RubyWarningFilter     11.934k (± 4.7%) i/s -     59.721k in   5.017126s
+#          plain File     81.435k (± 2.5%) i/s -    411.632k in   5.057905s
+#   RubyWarningFilter     41.323k (± 2.5%) i/s -    210.236k in   5.090913s
 Benchmark.ips do |x|
   x.report "plain File" do
     write_errors(file)
@@ -33,5 +35,3 @@ def write_errors(io)
     write_errors(filter)
   end
 end
-
-

test/ruby_warnings_filter_test.rb

@@ -15,7 +15,8 @@ def setup
   def test_no_effect
     assert_equal 0, @err.ruby_warnings
     @err.puts "hello"
-    assert_equal "hello\n", @err.string
+    @err.print "world", "\n"
+    assert_equal "hello\nworld\n", @err.string
     assert_equal 0, @err.ruby_warnings
   end
 
@@ -27,12 +28,17 @@ def test_ruby_warning
 
     @err.write "#{@gems_dir}/unicode_utils-1.4.0/lib/unicode_utils/sid.rb:11: warning: shadowing outer local variable - al\n"
     @err.write "/path/to/ruby/2.2.0/gems/unicode_utils-1.4.0/lib/unicode_utils/sid.rb:11: warning: shadowing outer local variable - al\n"
+    @err.write "/path/to/ruby/2.2.0/gems/fast_blank-1.0.0/lib/fast_blank.bundle: warning: method redefined; discarding old blank?"
 
     # This warning actually writes newline separately.
     @err.write "/path/to/ruby/2.2.0/gems/dragonfly-1.0.6/lib/dragonfly/utils.rb:41:in `uri_unescape': warning: URI.unescape is obsolete"
     @err.write "\n"
 
-    assert_equal "/path/to/script/middleware_test.rb:58: warning: assigned but unused variable - status\n",
+    # warn "custom warning"
+    @err.write "custom warning"
+    @err.write "\n"
+
+    assert_equal "/path/to/script/middleware_test.rb:58: warning: assigned but unused variable - status\ncustom warning\n",
       @err.string
     assert_equal 1, @err.ruby_warnings
   end
@@ -87,4 +93,11 @@ def test_template_warning
       @err.string
     assert_equal 1, @err.ruby_warnings
   end
+
+  def test_eval_warning
+    @err.write "<main>:1: warning: __FILE__ in eval may not return location in binding; use Binding#source_location instead\n"
+    @err.write "<main>: warning: __LINE__ in eval may not return location in binding; use Binding#source_location instead\n"
+    assert_equal "", @err.string
+    assert_equal 0, @err.ruby_warnings
+  end
 end