Search and compare tokens using hash lookups

lib/changit.rb

@@ -1,9 +1,10 @@
 require 'changit/version'
-require 'changit/git_dir_finder'
-require 'changit/config_reader'
 require 'changit/lexer/section_token'
 require 'changit/lexer/key_value_token'
 require 'changit/lexer'
+require 'changit/git_dir_finder'
+require 'changit/config_merger'
+require 'changit/config_reader'
 require 'changit/config_writer'
 
 module Changit

lib/changit/config_merger.rb

@@ -0,0 +1,32 @@
+module Changit
+  class ConfigMerger
+    def initialize(src_config, target_config)
+      @src = src_config
+      @target = target_config
+    end
+
+    def merge
+      src_lexer = Lexer.new(@src)
+      src_token_hash = src_lexer.token_hash
+
+      target_lexer = Lexer.new(@target)
+      target_token_hash = target_lexer.token_hash
+
+      if target_token_hash.empty?
+        target_lexer = src_lexer
+      else
+        target_token_hash.each do |k, v|
+          if src_token_hash[k]
+            target_token_hash[k].merge!(src_token_hash[k])
+          end
+        end
+
+        config_difference = src_token_hash.dup.delete_if { |k, _| target_token_hash.key?(k) }
+        target_token_hash.merge!(config_difference)
+        target_lexer.reconstruct_tokens_from_hash!
+      end
+
+      target_lexer
+    end
+  end
+end

lib/changit/config_writer.rb

@@ -6,36 +6,12 @@ def initialize(config, config_files)
       @config = config
       @config_files = config_files
     end
-
-    def write
-      config_lexer = Lexer.new(@config)
-      config_token_hash = config_lexer.token_hash
 
+    def write
       @config_files.each do |path|
-        file_lexer = Lexer.new(File.read(path))
-        file_token_hash = file_lexer.token_hash
-
-        unless file_token_hash.empty?
-          file_token_hash.each do |k, v|
-            if config_token_hash[k]
-              # calling `sort!` changes the order of the key_value pairs
-              config_token_hash[k].sort!
-              file_token_hash[k].sort!
-
-              config_token_hash[k].each_with_index do |e, i|
-                if v.include?(e)
-                  # update it
-                  file_token_hash[k][i].rhs = e.rhs
-                else
-                  # push it
-                  file_token_hash[k].push(e)
-                end
-              end
-            end
-          end
-        end
+        merged_config = ConfigMerger.new(@config, File.read(path)).merge
 
-        File.open(path, 'w') { |f| f.write(config_lexer.to_s); f.close }
+        File.open(path, 'w') { |f| f.write(merged_config.to_s); f.close }
       end
     end
   end

lib/changit/lexer.rb

@@ -17,6 +17,16 @@ def to_s
       @tokens.map(&:to_s).join
     end
 
+    def reconstruct_tokens_from_hash!
+      tokens = []
+      @token_hash.each do |section, key_value|
+        tokens << SectionToken.new(section)  
+        key_value.each { |lhs, rhs| tokens << KeyValueToken.new("#{lhs} = #{rhs}") }
+      end
+
+      @tokens = tokens
+    end
+
     private
 
     def tokenize
@@ -42,9 +52,9 @@ def to_hash
 
       @tokens.map do |token|
         if token.class == SectionToken
-          token_hash[token] = []
+          token_hash[token.section] = {}
         else
-          token_hash[token_hash.to_a.last[0]].push(token)
+          token_hash[token_hash.to_a.last[0]][token.lhs] = token.rhs
         end
       end
 

lib/changit/lexer/key_value_token.rb

@@ -1,8 +1,6 @@
 module Changit
   class Lexer
     class KeyValueToken
-      include Comparable
-
       attr_reader :lhs    # left-hand side
       attr_accessor :rhs  # right-hand side
 
@@ -13,10 +11,6 @@ def initialize(key_value)
       def to_s
         "\t#{@lhs} = #{@rhs}\n"
       end
-
-      def <=>(another)
-        self.lhs <=> another.lhs
-      end
     end
   end
 end

lib/changit/lexer/section_token.rb

@@ -1,7 +1,7 @@
 module Changit
   class Lexer
     class SectionToken
-      attr_reader :section
+      attr_accessor :section
 
       def initialize(section)
         @section = section

lib/changit/version.rb

@@ -1,3 +1,3 @@
 module Changit
-  VERSION='0.2.0'
+  VERSION='0.2.2'
 end

test/config_writer_test.rb

@@ -5,9 +5,11 @@
 class ConfigWriterTest < Minitest::Test
   def test_write_to_existing_file
     writer = config_writer
+    expected = Changit::ConfigMerger.new(writer.config, File.read(writer.config_files.first)).merge.to_s
+
     writer.write
 
-    assert writer.config == File.read(writer.config_files.first)
+    assert expected == File.read(writer.config_files.first)
   end
 
   def test_write_to_empty_file
@@ -21,8 +23,9 @@ def test_write_to_empty_file
 
   def config_writer
     config = "[user]\n\tname = testname\n\temail = [email protected]\n[core]\n\teditor = vim\n[color]\n\tui = true\n[rebase]\n\tautosquash = true\n".freeze
+
     # this creates an actual file in /tmp you should remove it if you want to
-    config_files = [File.new("/tmp/config1237879867", 'w')]
+    config_files = [File.new("/tmp/config1237879867", 'a')]
 
     Changit::ConfigWriter.new(config, config_files)
   end

test/lexer_test.rb

@@ -4,19 +4,29 @@
 
 class LexerTest < Minitest::Test
   def test_tokenize
-    tokens = lexer.tokens
+    l = lexer
+    tokens = l.tokens
 
     assert_kind_of Array, tokens
     refute_empty tokens
-    assert_equal tokens.size, lexer.original_expression.each_line.count
+    assert_equal tokens.size, l.original_expression.each_line.count
   end
 
   def test_to_hash
-    token_hash = lexer.token_hash
+    l = lexer
+    token_hash = l.token_hash
 
     assert_kind_of Hash, token_hash
     refute_empty token_hash
-    assert_kind_of_array Changit::Lexer::SectionToken, token_hash.keys
+  end
+
+  def test_reconstruct_tokens_from_hash
+    l = lexer
+    old_tokens = l.tokens
+    l.token_hash["[user]"].merge!({ 'name' => 'newname' })
+    l.reconstruct_tokens_from_hash!
+
+    refute_equal lexer.tokens, old_tokens
   end
 
   private