From 2b3ea25bf052c1be731cf871f14ad15f1571d0b9 Mon Sep 17 00:00:00 2001
From: Awesome Code <team@xinminlabs.com>
Date: Sun, 17 Jan 2021 05:49:45 +0000
Subject: [PATCH 1/6] Auto corrected by following Lint Ruby Style/RaiseArgs

---
 lib/synvert/core/node_ext.rb          | 40 +++++++++++++--------------
 lib/synvert/core/rewriter.rb          |  4 +--
 lib/synvert/core/rewriter/gem_spec.rb |  2 +-
 3 files changed, 23 insertions(+), 23 deletions(-)

diff --git a/lib/synvert/core/node_ext.rb b/lib/synvert/core/node_ext.rb
index 046adbfb..a148b986 100644
--- a/lib/synvert/core/node_ext.rb
+++ b/lib/synvert/core/node_ext.rb
@@ -39,7 +39,7 @@ def name
       when :mlhs
         self
       else
-        raise Synvert::Core::MethodNotSupported.new "name is not handled for #{self.debug_info}"
+        raise Synvert::Core::MethodNotSupported, "name is not handled for #{self.debug_info}"
       end
     end
 
@@ -51,7 +51,7 @@ def parent_class
       if :class == self.type
         self.children[1]
       else
-        raise Synvert::Core::MethodNotSupported.new "parent_class is not handled for #{self.debug_info}"
+        raise Synvert::Core::MethodNotSupported, "parent_class is not handled for #{self.debug_info}"
       end
     end
 
@@ -63,7 +63,7 @@ def parent_const
       if :const == self.type
         self.children[0]
       else
-        raise Synvert::Core::MethodNotSupported.new "parent_const is not handled for #{self.debug_info}"
+        raise Synvert::Core::MethodNotSupported, "parent_const is not handled for #{self.debug_info}"
       end
     end
 
@@ -75,7 +75,7 @@ def receiver
       if :send == self.type
         self.children[0]
       else
-        raise Synvert::Core::MethodNotSupported.new "receiver is not handled for #{self.debug_info}"
+        raise Synvert::Core::MethodNotSupported, "receiver is not handled for #{self.debug_info}"
       end
     end
 
@@ -90,7 +90,7 @@ def message
       when :send
         self.children[1]
       else
-        raise Synvert::Core::MethodNotSupported.new "message is not handled for #{self.debug_info}"
+        raise Synvert::Core::MethodNotSupported, "message is not handled for #{self.debug_info}"
       end
     end
 
@@ -109,7 +109,7 @@ def arguments
       when :defined?
         self.children
       else
-        raise Synvert::Core::MethodNotSupported.new "arguments is not handled for #{self.debug_info}"
+        raise Synvert::Core::MethodNotSupported, "arguments is not handled for #{self.debug_info}"
       end
     end
 
@@ -121,7 +121,7 @@ def caller
       if :block == self.type
         self.children[0]
       else
-        raise Synvert::Core::MethodNotSupported.new "caller is not handled for #{self.debug_info}"
+        raise Synvert::Core::MethodNotSupported, "caller is not handled for #{self.debug_info}"
       end
     end
 
@@ -142,7 +142,7 @@ def body
 
         :begin == self.children[3].type ? self.children[3].body : self.children[3..-1]
       else
-        raise Synvert::Core::MethodNotSupported.new "body is not handled for #{self.debug_info}"
+        raise Synvert::Core::MethodNotSupported, "body is not handled for #{self.debug_info}"
       end
     end
 
@@ -154,7 +154,7 @@ def condition
       if :if == self.type
         self.children[0]
       else
-        raise Synvert::Core::MethodNotSupported.new "condition is not handled for #{self.debug_info}"
+        raise Synvert::Core::MethodNotSupported, "condition is not handled for #{self.debug_info}"
       end
     end
 
@@ -166,7 +166,7 @@ def keys
       if :hash == self.type
         self.children.map { |child| child.children[0] }
       else
-        raise Synvert::Core::MethodNotSupported.new "keys is not handled for #{self.debug_info}"
+        raise Synvert::Core::MethodNotSupported, "keys is not handled for #{self.debug_info}"
       end
     end
 
@@ -178,7 +178,7 @@ def values
       if :hash == self.type
         self.children.map { |child| child.children[1] }
       else
-        raise Synvert::Core::MethodNotSupported.new "keys is not handled for #{self.debug_info}"
+        raise Synvert::Core::MethodNotSupported, "keys is not handled for #{self.debug_info}"
       end
     end
 
@@ -191,7 +191,7 @@ def has_key?(key)
       if :hash == self.type
         self.children.any? { |pair_node| pair_node.key.to_value == key }
       else
-        raise Synvert::Core::MethodNotSupported.new "has_key? is not handled for #{self.debug_info}"
+        raise Synvert::Core::MethodNotSupported, "has_key? is not handled for #{self.debug_info}"
       end
     end
 
@@ -205,7 +205,7 @@ def hash_value(key)
         value_node = self.children.find { |pair_node| pair_node.key.to_value == key }
         value_node ? value_node.value : nil
       else
-        raise Synvert::Core::MethodNotSupported.new "has_key? is not handled for #{self.debug_info}"
+        raise Synvert::Core::MethodNotSupported, "has_key? is not handled for #{self.debug_info}"
       end
     end
 
@@ -217,7 +217,7 @@ def key
       if :pair == self.type
         self.children.first
       else
-        raise Synvert::Core::MethodNotSupported.new "key is not handled for #{self.debug_info}"
+        raise Synvert::Core::MethodNotSupported, "key is not handled for #{self.debug_info}"
       end
     end
 
@@ -229,7 +229,7 @@ def value
       if :pair == self.type
         self.children.last
       else
-        raise Synvert::Core::MethodNotSupported.new "value is not handled for #{self.debug_info}"
+        raise Synvert::Core::MethodNotSupported, "value is not handled for #{self.debug_info}"
       end
     end
 
@@ -241,7 +241,7 @@ def left_value
       if %i[masgn lvasgn ivasgn].include? self.type
         self.children[0]
       else
-        raise Synvert::Core::MethodNotSupported.new "left_value is not handled for #{self.debug_info}"
+        raise Synvert::Core::MethodNotSupported, "left_value is not handled for #{self.debug_info}"
       end
     end
 
@@ -253,7 +253,7 @@ def right_value
       if %i[masgn lvasgn ivasgn].include? self.type
         self.children[1]
       else
-        raise Synvert::Core::MethodNotSupported.new "right_value is not handled for #{self.debug_info}"
+        raise Synvert::Core::MethodNotSupported, "right_value is not handled for #{self.debug_info}"
       end
     end
 
@@ -276,7 +276,7 @@ def to_value
       when :begin
         self.children.first.to_value
       else
-        raise Synvert::Core::MethodNotSupported.new "to_value is not handled for #{self.debug_info}"
+        raise Synvert::Core::MethodNotSupported, "to_value is not handled for #{self.debug_info}"
       end
     end
 
@@ -389,7 +389,7 @@ def rewritten_source(code)
           when NilClass
             'nil'
           else
-            raise Synvert::Core::MethodNotSupported.new "rewritten_source is not handled for #{evaluated.inspect}"
+            raise Synvert::Core::MethodNotSupported, "rewritten_source is not handled for #{evaluated.inspect}"
           end
         else
           "{{#{old_code}}}"
@@ -446,7 +446,7 @@ def match_value?(actual, expected)
       when Parser::AST::Node
         actual == expected
       else
-        raise Synvert::Core::MethodNotSupported.new "#{expected.class} is not handled for match_value?"
+        raise Synvert::Core::MethodNotSupported, "#{expected.class} is not handled for match_value?"
       end
     end
 
diff --git a/lib/synvert/core/rewriter.rb b/lib/synvert/core/rewriter.rb
index f436d843..43760511 100644
--- a/lib/synvert/core/rewriter.rb
+++ b/lib/synvert/core/rewriter.rb
@@ -65,7 +65,7 @@ def fetch(group, name)
         if exist? group, name
           rewriters[group][name]
         else
-          raise RewriterNotFound.new "Rewriter #{group} #{name} not found"
+          raise RewriterNotFound, "Rewriter #{group} #{name} not found"
         end
       end
 
@@ -82,7 +82,7 @@ def call(group, name)
           rewriter.process
           rewriter
         else
-          raise RewriterNotFound.new "Rewriter #{group}/#{name} not found"
+          raise RewriterNotFound, "Rewriter #{group}/#{name} not found"
         end
       end
 
diff --git a/lib/synvert/core/rewriter/gem_spec.rb b/lib/synvert/core/rewriter/gem_spec.rb
index 6d5ad45c..469e7d7d 100644
--- a/lib/synvert/core/rewriter/gem_spec.rb
+++ b/lib/synvert/core/rewriter/gem_spec.rb
@@ -35,7 +35,7 @@ def match?
           false
         end
       else
-        raise GemfileLockNotFound.new 'Gemfile.lock does not exist'
+        raise GemfileLockNotFound, 'Gemfile.lock does not exist'
       end
     end
   end

From 379cdce49773028bcbb6f8a07b56be16998092de Mon Sep 17 00:00:00 2001
From: Awesome Code <team@xinminlabs.com>
Date: Sun, 17 Jan 2021 05:50:02 +0000
Subject: [PATCH 2/6] Auto corrected by following Lint Ruby
 Style/SafeNavigation

---
 lib/synvert/core/node_ext.rb                                  | 4 +---
 lib/synvert/core/rewriter/condition/if_exist_condition.rb     | 2 +-
 lib/synvert/core/rewriter/condition/unless_exist_condition.rb | 2 +-
 3 files changed, 3 insertions(+), 5 deletions(-)

diff --git a/lib/synvert/core/node_ext.rb b/lib/synvert/core/node_ext.rb
index 046adbfb..07101a93 100644
--- a/lib/synvert/core/node_ext.rb
+++ b/lib/synvert/core/node_ext.rb
@@ -299,9 +299,7 @@ def debug_info
     #
     # @return [String] source code.
     def to_source
-      if self.loc.expression
-        self.loc.expression.source
-      end
+      self.loc.expression&.source
     end
 
     # Get the indent of current node.
diff --git a/lib/synvert/core/rewriter/condition/if_exist_condition.rb b/lib/synvert/core/rewriter/condition/if_exist_condition.rb
index 16d74ec3..836e7238 100644
--- a/lib/synvert/core/rewriter/condition/if_exist_condition.rb
+++ b/lib/synvert/core/rewriter/condition/if_exist_condition.rb
@@ -7,7 +7,7 @@ class Rewriter::IfExistCondition < Rewriter::Condition
     def match?
       match = false
       @instance.current_node.recursive_children do |child_node|
-        match = match || (child_node && child_node.match?(@rules))
+        match = match || (child_node&.match?(@rules))
       end
       match
     end
diff --git a/lib/synvert/core/rewriter/condition/unless_exist_condition.rb b/lib/synvert/core/rewriter/condition/unless_exist_condition.rb
index 3dc27eac..ef3e0ee7 100644
--- a/lib/synvert/core/rewriter/condition/unless_exist_condition.rb
+++ b/lib/synvert/core/rewriter/condition/unless_exist_condition.rb
@@ -7,7 +7,7 @@ class Rewriter::UnlessExistCondition < Rewriter::Condition
     def match?
       match = false
       @instance.current_node.recursive_children do |child_node|
-        match = match || (child_node && child_node.match?(@rules))
+        match = match || (child_node&.match?(@rules))
       end
       !match
     end

From 5e3d01d2c7d70ff29fe41797f192e7f309cd1e1a Mon Sep 17 00:00:00 2001
From: Richard Huang <flyerhzm@gmail.com>
Date: Sun, 17 Jan 2021 16:55:28 +0800
Subject: [PATCH 3/6] within_scope supports array of nodes

---
 .../core/rewriter/scope/within_scope.rb       | 25 ++++++++-----------
 1 file changed, 11 insertions(+), 14 deletions(-)

diff --git a/lib/synvert/core/rewriter/scope/within_scope.rb b/lib/synvert/core/rewriter/scope/within_scope.rb
index 229fe564..cf238548 100644
--- a/lib/synvert/core/rewriter/scope/within_scope.rb
+++ b/lib/synvert/core/rewriter/scope/within_scope.rb
@@ -22,23 +22,20 @@ def process
       current_node = @instance.current_node
       return unless current_node
 
-      @instance.process_with_node current_node do
-        matching_nodes = []
-        matching_nodes << current_node if current_node.match? @rules
-        if @options[:recursive]
-          current_node.recursive_children do |child_node|
-            matching_nodes << child_node if child_node.match? @rules
-          end
-        else
-          current_node.children do |child_node|
-            matching_nodes << child_node if child_node.match? @rules
-          end
-        end
-        matching_nodes.each do |matching_node|
-          @instance.process_with_node matching_node do
+      child_nodes = current_node.is_a?(Parser::AST::Node) ? current_node.children : current_node
+      process_with_nodes(child_nodes)
+    end
+
+    private
+
+    def process_with_nodes(nodes)
+      nodes.compact.select { |node| node.is_a?(Parser::AST::Node) }.each do |node|
+        if node.match?(@rules)
+          @instance.process_with_node(node) do
             @instance.instance_eval &@block
           end
         end
+        process_with_nodes(node.children) if @options[:recursive]
       end
     end
   end

From 0893b59e4a2e5b94716d0a8e7269688b45f36f20 Mon Sep 17 00:00:00 2001
From: Awesome Code <team@xinminlabs.com>
Date: Sun, 17 Jan 2021 09:00:17 +0000
Subject: [PATCH 4/6] Auto corrected by following Lint Ruby Style/RedundantSelf

---
 lib/synvert/core/node_ext.rb          | 154 +++++++++++++-------------
 lib/synvert/core/rewriter.rb          |   4 +-
 lib/synvert/core/rewriter/instance.rb |   6 +-
 3 files changed, 82 insertions(+), 82 deletions(-)

diff --git a/lib/synvert/core/node_ext.rb b/lib/synvert/core/node_ext.rb
index f2c89516..05e15643 100644
--- a/lib/synvert/core/node_ext.rb
+++ b/lib/synvert/core/node_ext.rb
@@ -31,15 +31,15 @@ class Node
     # @return [Parser::AST::Node] name node.
     # @raise [Synvert::Core::MethodNotSupported] if calls on other node.
     def name
-      case self.type
+      case type
       when :class, :module, :def, :arg, :blockarg, :restarg
-        self.children[0]
+        children[0]
       when :defs, :const
-        self.children[1]
+        children[1]
       when :mlhs
         self
       else
-        raise Synvert::Core::MethodNotSupported, "name is not handled for #{self.debug_info}"
+        raise Synvert::Core::MethodNotSupported, "name is not handled for #{debug_info}"
       end
     end
 
@@ -48,10 +48,10 @@ def name
     # @return [Parser::AST::Node] parent_class node.
     # @raise [Synvert::Core::MethodNotSupported] if calls on other node.
     def parent_class
-      if :class == self.type
-        self.children[1]
+      if :class == type
+        children[1]
       else
-        raise Synvert::Core::MethodNotSupported, "parent_class is not handled for #{self.debug_info}"
+        raise Synvert::Core::MethodNotSupported, "parent_class is not handled for #{debug_info}"
       end
     end
 
@@ -60,10 +60,10 @@ def parent_class
     # @return [Parser::AST::Node] parent const node.
     # @raise [Synvert::Core::MethodNotSupported] if calls on other node.
     def parent_const
-      if :const == self.type
-        self.children[0]
+      if :const == type
+        children[0]
       else
-        raise Synvert::Core::MethodNotSupported, "parent_const is not handled for #{self.debug_info}"
+        raise Synvert::Core::MethodNotSupported, "parent_const is not handled for #{debug_info}"
       end
     end
 
@@ -72,10 +72,10 @@ def parent_const
     # @return [Parser::AST::Node] receiver node.
     # @raise [Synvert::Core::MethodNotSupported] if calls on other node.
     def receiver
-      if :send == self.type
-        self.children[0]
+      if :send == type
+        children[0]
       else
-        raise Synvert::Core::MethodNotSupported, "receiver is not handled for #{self.debug_info}"
+        raise Synvert::Core::MethodNotSupported, "receiver is not handled for #{debug_info}"
       end
     end
 
@@ -84,13 +84,13 @@ def receiver
     # @return [Parser::AST::Node] mesage node.
     # @raise [Synvert::Core::MethodNotSupported] if calls on other node.
     def message
-      case self.type
+      case type
       when :super, :zsuper
         :super
       when :send
-        self.children[1]
+        children[1]
       else
-        raise Synvert::Core::MethodNotSupported, "message is not handled for #{self.debug_info}"
+        raise Synvert::Core::MethodNotSupported, "message is not handled for #{debug_info}"
       end
     end
 
@@ -99,17 +99,17 @@ def message
     # @return [Array<Parser::AST::Node>] arguments node.
     # @raise [Synvert::Core::MethodNotSupported] if calls on other node.
     def arguments
-      case self.type
+      case type
       when :def, :block
-        ArgumentsNode.new self.children[1]
+        ArgumentsNode.new children[1]
       when :defs
-        ArgumentsNode.new self.children[2]
+        ArgumentsNode.new children[2]
       when :send
-        self.children[2..-1]
+        children[2..-1]
       when :defined?
-        self.children
+        children
       else
-        raise Synvert::Core::MethodNotSupported, "arguments is not handled for #{self.debug_info}"
+        raise Synvert::Core::MethodNotSupported, "arguments is not handled for #{debug_info}"
       end
     end
 
@@ -118,10 +118,10 @@ def arguments
     # @return [Parser::AST::Node] caller node.
     # @raise [Synvert::Core::MethodNotSupported] if calls on other node.
     def caller
-      if :block == self.type
-        self.children[0]
+      if :block == type
+        children[0]
       else
-        raise Synvert::Core::MethodNotSupported, "caller is not handled for #{self.debug_info}"
+        raise Synvert::Core::MethodNotSupported, "caller is not handled for #{debug_info}"
       end
     end
 
@@ -130,19 +130,19 @@ def caller
     # @return [Array<Parser::AST::Node>] body node.
     # @raise [Synvert::Core::MethodNotSupported] if calls on other node.
     def body
-      case self.type
+      case type
       when :begin
-        self.children
+        children
       when :def, :block
-        return [] if self.children[2].nil?
+        return [] if children[2].nil?
 
-        :begin == self.children[2].type ? self.children[2].body : self.children[2..-1]
+        :begin == children[2].type ? children[2].body : children[2..-1]
       when :defs
-        return [] if self.children[3].nil?
+        return [] if children[3].nil?
 
-        :begin == self.children[3].type ? self.children[3].body : self.children[3..-1]
+        :begin == children[3].type ? children[3].body : children[3..-1]
       else
-        raise Synvert::Core::MethodNotSupported, "body is not handled for #{self.debug_info}"
+        raise Synvert::Core::MethodNotSupported, "body is not handled for #{debug_info}"
       end
     end
 
@@ -151,10 +151,10 @@ def body
     # @return [Parser::AST::Node] condition node.
     # @raise [Synvert::Core::MethodNotSupported] if calls on other node.
     def condition
-      if :if == self.type
-        self.children[0]
+      if :if == type
+        children[0]
       else
-        raise Synvert::Core::MethodNotSupported, "condition is not handled for #{self.debug_info}"
+        raise Synvert::Core::MethodNotSupported, "condition is not handled for #{debug_info}"
       end
     end
 
@@ -163,10 +163,10 @@ def condition
     # @return [Array<Parser::AST::Node>] keys node.
     # @raise [Synvert::Core::MethodNotSupported] if calls on other node.
     def keys
-      if :hash == self.type
-        self.children.map { |child| child.children[0] }
+      if :hash == type
+        children.map { |child| child.children[0] }
       else
-        raise Synvert::Core::MethodNotSupported, "keys is not handled for #{self.debug_info}"
+        raise Synvert::Core::MethodNotSupported, "keys is not handled for #{debug_info}"
       end
     end
 
@@ -175,10 +175,10 @@ def keys
     # @return [Array<Parser::AST::Node>] values node.
     # @raise [Synvert::Core::MethodNotSupported] if calls on other node.
     def values
-      if :hash == self.type
-        self.children.map { |child| child.children[1] }
+      if :hash == type
+        children.map { |child| child.children[1] }
       else
-        raise Synvert::Core::MethodNotSupported, "keys is not handled for #{self.debug_info}"
+        raise Synvert::Core::MethodNotSupported, "keys is not handled for #{debug_info}"
       end
     end
 
@@ -188,10 +188,10 @@ def values
     # @return [Boolean] true if specified key exists.
     # @raise [Synvert::Core::MethodNotSupported] if calls on other node.
     def has_key?(key)
-      if :hash == self.type
-        self.children.any? { |pair_node| pair_node.key.to_value == key }
+      if :hash == type
+        children.any? { |pair_node| pair_node.key.to_value == key }
       else
-        raise Synvert::Core::MethodNotSupported, "has_key? is not handled for #{self.debug_info}"
+        raise Synvert::Core::MethodNotSupported, "has_key? is not handled for #{debug_info}"
       end
     end
 
@@ -201,11 +201,11 @@ def has_key?(key)
     # @return [Parser::AST::Node] value node.
     # @raise [Synvert::Core::MethodNotSupported] if calls on other node.
     def hash_value(key)
-      if :hash == self.type
-        value_node = self.children.find { |pair_node| pair_node.key.to_value == key }
+      if :hash == type
+        value_node = children.find { |pair_node| pair_node.key.to_value == key }
         value_node ? value_node.value : nil
       else
-        raise Synvert::Core::MethodNotSupported, "has_key? is not handled for #{self.debug_info}"
+        raise Synvert::Core::MethodNotSupported, "has_key? is not handled for #{debug_info}"
       end
     end
 
@@ -214,10 +214,10 @@ def hash_value(key)
     # @return [Parser::AST::Node] key node.
     # @raise [Synvert::Core::MethodNotSupported] if calls on other node.
     def key
-      if :pair == self.type
-        self.children.first
+      if :pair == type
+        children.first
       else
-        raise Synvert::Core::MethodNotSupported, "key is not handled for #{self.debug_info}"
+        raise Synvert::Core::MethodNotSupported, "key is not handled for #{debug_info}"
       end
     end
 
@@ -226,10 +226,10 @@ def key
     # @return [Parser::AST::Node] value node.
     # @raise [Synvert::Core::MethodNotSupported] if calls on other node.
     def value
-      if :pair == self.type
-        self.children.last
+      if :pair == type
+        children.last
       else
-        raise Synvert::Core::MethodNotSupported, "value is not handled for #{self.debug_info}"
+        raise Synvert::Core::MethodNotSupported, "value is not handled for #{debug_info}"
       end
     end
 
@@ -238,10 +238,10 @@ def value
     # @return [Parser::AST::Node] variable nodes.
     # @raise [Synvert::Core::MethodNotSupported] if calls on other node.
     def left_value
-      if %i[masgn lvasgn ivasgn].include? self.type
-        self.children[0]
+      if %i[masgn lvasgn ivasgn].include? type
+        children[0]
       else
-        raise Synvert::Core::MethodNotSupported, "left_value is not handled for #{self.debug_info}"
+        raise Synvert::Core::MethodNotSupported, "left_value is not handled for #{debug_info}"
       end
     end
 
@@ -250,10 +250,10 @@ def left_value
     # @return [Array<Parser::AST::Node>] variable nodes.
     # @raise [Synvert::Core::MethodNotSupported] if calls on other node.
     def right_value
-      if %i[masgn lvasgn ivasgn].include? self.type
-        self.children[1]
+      if %i[masgn lvasgn ivasgn].include? type
+        children[1]
       else
-        raise Synvert::Core::MethodNotSupported, "right_value is not handled for #{self.debug_info}"
+        raise Synvert::Core::MethodNotSupported, "right_value is not handled for #{debug_info}"
       end
     end
 
@@ -262,36 +262,36 @@ def right_value
     # @return [Object] exact value.
     # @raise [Synvert::Core::MethodNotSupported] if calls on other node.
     def to_value
-      case self.type
+      case type
       when :int, :str, :sym
-        self.children.last
+        children.last
       when :true
         true
       when :false
         false
       when :array
-        self.children.map(&:to_value)
+        children.map(&:to_value)
       when :irange
-        (self.children.first.to_value..self.children.last.to_value)
+        (children.first.to_value..children.last.to_value)
       when :begin
-        self.children.first.to_value
+        children.first.to_value
       else
-        raise Synvert::Core::MethodNotSupported, "to_value is not handled for #{self.debug_info}"
+        raise Synvert::Core::MethodNotSupported, "to_value is not handled for #{debug_info}"
       end
     end
 
     def to_s
-      if :mlhs == self.type
-        "(#{self.children.map(&:name).join(', ')})"
+      if :mlhs == type
+        "(#{children.map(&:name).join(', ')})"
       end
     end
 
     def debug_info
       "\n" + [
-        "file: #{self.loc.expression.source_buffer.name}",
-        "line: #{self.loc.expression.line}",
-        "source: #{self.to_source}",
-        "node: #{self.inspect}"
+        "file: #{loc.expression.source_buffer.name}",
+        "line: #{loc.expression.line}",
+        "source: #{to_source}",
+        "node: #{inspect}"
       ].join("\n")
     end
 
@@ -299,21 +299,21 @@ def debug_info
     #
     # @return [String] source code.
     def to_source
-      self.loc.expression&.source
+      loc.expression&.source
     end
 
     # Get the indent of current node.
     #
     # @return [Integer] indent.
     def indent
-      self.loc.expression.column
+      loc.expression.column
     end
 
     # Get the line of current node.
     #
     # @return [Integer] line.
     def line
-      self.loc.expression.line
+      loc.expression.line
     end
 
     # Recursively iterate all child nodes of current node.
@@ -321,7 +321,7 @@ def line
     # @yield [child] Gives a child node.
     # @yieldparam child [Parser::AST::Node] child node
     def recursive_children
-      self.children.each do |child|
+      children.each do |child|
         if Parser::AST::Node === child
           yield child
           child.recursive_children { |c| yield c }
@@ -361,8 +361,8 @@ def match?(rules)
     def rewritten_source(code)
       code.gsub(/{{(.*?)}}/m) do
         old_code = $1
-        if self.respond_to? old_code.split(/\.|\[/).first
-          evaluated = self.instance_eval old_code
+        if respond_to? old_code.split(/\.|\[/).first
+          evaluated = instance_eval old_code
           case evaluated
           when Parser::AST::Node
             evaluated.loc.expression.source
diff --git a/lib/synvert/core/rewriter.rb b/lib/synvert/core/rewriter.rb
index 43760511..a58829fd 100644
--- a/lib/synvert/core/rewriter.rb
+++ b/lib/synvert/core/rewriter.rb
@@ -151,14 +151,14 @@ def initialize(group, name, &block)
     # Process the rewriter.
     # It will call the block.
     def process
-      self.instance_eval &@block
+      instance_eval &@block
     end
 
     # Process rewriter with sandbox mode.
     # It will call the block but doesn't change any file.
     def process_with_sandbox
       @sandbox = true
-      self.process
+      process
       @sandbox = false
     end
 
diff --git a/lib/synvert/core/rewriter/instance.rb b/lib/synvert/core/rewriter/instance.rb
index e9c71672..438fa338 100644
--- a/lib/synvert/core/rewriter/instance.rb
+++ b/lib/synvert/core/rewriter/instance.rb
@@ -79,7 +79,7 @@ def initialize(rewriter, file_pattern, options={}, &block)
       @file_pattern = file_pattern
       @options = DEFAULT_OPTIONS.merge(options)
       @block = block
-      rewriter.helpers.each { |helper| self.singleton_class.send(:define_method, helper[:name], &helper[:block]) }
+      rewriter.helpers.each { |helper| singleton_class.send(:define_method, helper[:name], &helper[:block]) }
     end
 
     # Process the instance.
@@ -96,7 +96,7 @@ def process
 
             @current_file = file_path
 
-            self.process_with_node ast do
+            process_with_node ast do
               begin
                 instance_eval &@block
               rescue NoMethodError
@@ -146,7 +146,7 @@ def process_with_node(node)
     # @param node [Parser::AST::Node] node set to current_node
     # @yield process
     def process_with_other_node(node)
-      original_node = self.current_node
+      original_node = current_node
       self.current_node = node
       yield
       self.current_node = original_node

From f5e4bf6f115dc6d55b6e910b35e1f033c8591612 Mon Sep 17 00:00:00 2001
From: Awesome Code <team@xinminlabs.com>
Date: Sun, 17 Jan 2021 09:00:25 +0000
Subject: [PATCH 5/6] Auto corrected by following Lint Ruby
 Style/SelfAssignment

---
 lib/synvert/core/rewriter/condition/if_exist_condition.rb     | 2 +-
 lib/synvert/core/rewriter/condition/unless_exist_condition.rb | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/synvert/core/rewriter/condition/if_exist_condition.rb b/lib/synvert/core/rewriter/condition/if_exist_condition.rb
index 836e7238..d3b8dfc4 100644
--- a/lib/synvert/core/rewriter/condition/if_exist_condition.rb
+++ b/lib/synvert/core/rewriter/condition/if_exist_condition.rb
@@ -7,7 +7,7 @@ class Rewriter::IfExistCondition < Rewriter::Condition
     def match?
       match = false
       @instance.current_node.recursive_children do |child_node|
-        match = match || (child_node&.match?(@rules))
+        match ||= (child_node&.match?(@rules))
       end
       match
     end
diff --git a/lib/synvert/core/rewriter/condition/unless_exist_condition.rb b/lib/synvert/core/rewriter/condition/unless_exist_condition.rb
index ef3e0ee7..a66105ed 100644
--- a/lib/synvert/core/rewriter/condition/unless_exist_condition.rb
+++ b/lib/synvert/core/rewriter/condition/unless_exist_condition.rb
@@ -7,7 +7,7 @@ class Rewriter::UnlessExistCondition < Rewriter::Condition
     def match?
       match = false
       @instance.current_node.recursive_children do |child_node|
-        match = match || (child_node&.match?(@rules))
+        match ||= (child_node&.match?(@rules))
       end
       !match
     end

From 8eca7c88897721368961f9ab2c0182415ccb0a2f Mon Sep 17 00:00:00 2001
From: Awesome Code <team@xinminlabs.com>
Date: Sun, 17 Jan 2021 09:05:53 +0000
Subject: [PATCH 6/6] Auto corrected by following Lint Ruby Style/PerlBackrefs

---
 lib/synvert/core/engine/erb.rb      | 14 +++++++-------
 lib/synvert/core/node_ext.rb        |  2 +-
 lib/synvert/core/rewriter/helper.rb |  6 +++---
 3 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/lib/synvert/core/engine/erb.rb b/lib/synvert/core/engine/erb.rb
index 34dcadf7..64136cc3 100644
--- a/lib/synvert/core/engine/erb.rb
+++ b/lib/synvert/core/engine/erb.rb
@@ -31,18 +31,18 @@ def decode(source)
       private
 
         def decode_ruby_stmt(source)
-          source.gsub(/#{ERUBY_STMT_SPLITTER}(.+?)#{ERUBY_STMT_SPLITTER}/m) { "<%#{$1}%>" }
+          source.gsub(/#{ERUBY_STMT_SPLITTER}(.+?)#{ERUBY_STMT_SPLITTER}/m) { "<%#{Regexp.last_match(1)}%>" }
         end
 
         def decode_ruby_output(source)
-          source.gsub(/@output_buffer.append=\((.+?)\);#{ERUBY_EXPR_SPLITTER}/m) { "<%=#{$1}%>" }
+          source.gsub(/@output_buffer.append=\((.+?)\);#{ERUBY_EXPR_SPLITTER}/m) { "<%=#{Regexp.last_match(1)}%>" }
             .gsub(/@output_buffer.append= (.+?)\s+(do|\{)(\s*\|[^|]*\|)?\s*#{ERUBY_EXPR_SPLITTER}/m) { |m| "<%=#{m.sub("@output_buffer.append= ", "").sub(ERUBY_EXPR_SPLITTER, "")}%>" }
         end
 
         def decode_html_output(source)
-          source.gsub(/@output_buffer.safe_append='(.+?)'.freeze;/m) { reverse_escape_text($1) }
-            .gsub(/@output_buffer.safe_append=\((.+?)\);#{ERUBY_EXPR_SPLITTER}/m) { reverse_escape_text($1) }
-            .gsub(/@output_buffer.safe_append=(.+?)\s+(do|\{)(\s*\|[^|]*\|)?\s*#{ERUBY_EXPR_SPLITTER}/m) { reverse_escape_text($1) }
+          source.gsub(/@output_buffer.safe_append='(.+?)'.freeze;/m) { reverse_escape_text(Regexp.last_match(1)) }
+            .gsub(/@output_buffer.safe_append=\((.+?)\);#{ERUBY_EXPR_SPLITTER}/m) { reverse_escape_text(Regexp.last_match(1)) }
+            .gsub(/@output_buffer.safe_append=(.+?)\s+(do|\{)(\s*\|[^|]*\|)?\s*#{ERUBY_EXPR_SPLITTER}/m) { reverse_escape_text(Regexp.last_match(1)) }
         end
 
         def remove_erubis_buf(source)
@@ -112,9 +112,9 @@ def add_stmt(src, code)
         flush_newline_if_pending(src)
         if code != "\n" && code != ""
           index = if code =~ /\A(\s*)\r?\n/
-                    $1.length
+                    Regexp.last_match(1).length
                   elsif code =~ /\A(\s+)/
-                    $1.end_with?(' ') ? $1.length - 1 : $1.length
+                    Regexp.last_match(1).end_with?(' ') ? Regexp.last_match(1).length - 1 : Regexp.last_match(1).length
                   else
                     0
                   end
diff --git a/lib/synvert/core/node_ext.rb b/lib/synvert/core/node_ext.rb
index 05e15643..28b6d0b8 100644
--- a/lib/synvert/core/node_ext.rb
+++ b/lib/synvert/core/node_ext.rb
@@ -360,7 +360,7 @@ def match?(rules)
     # @raise [Synvert::Core::MethodNotSupported] if string in block {{ }} does not support.
     def rewritten_source(code)
       code.gsub(/{{(.*?)}}/m) do
-        old_code = $1
+        old_code = Regexp.last_match(1)
         if respond_to? old_code.split(/\.|\[/).first
           evaluated = instance_eval old_code
           case evaluated
diff --git a/lib/synvert/core/rewriter/helper.rb b/lib/synvert/core/rewriter/helper.rb
index 98da9e68..b63980db 100644
--- a/lib/synvert/core/rewriter/helper.rb
+++ b/lib/synvert/core/rewriter/helper.rb
@@ -65,9 +65,9 @@ def add_curly_brackets_if_necessary(code)
     #
     #   strip_brackets("(1..100)") #=> "1..100"
     def strip_brackets(code)
-      code.sub(/^\((.*)\)$/) { $1 }
-          .sub(/^\[(.*)\]$/) { $1 }
-          .sub(/^{(.*)}$/) { $1 }
+      code.sub(/^\((.*)\)$/) { Regexp.last_match(1) }
+          .sub(/^\[(.*)\]$/) { Regexp.last_match(1) }
+          .sub(/^{(.*)}$/) { Regexp.last_match(1) }
     end
   end
 end