Fix incorrect Batched suggestions applications

lib/gitlab/suggestions/file_suggestion.rb

@@ -7,17 +7,14 @@ module Gitlab
 
       SuggestionForDifferentFileError = Class.new(StandardError)
 
-      def initialize
-        @suggestions = []
-      end
-
-      def add_suggestion(new_suggestion)
-        if for_different_file?(new_suggestion)
-          raise SuggestionForDifferentFileError,
-                'Only add suggestions for the same file.'
-        end
+      attr_reader :file_path
+      attr_reader :blob
+      attr_reader :suggestions
 
-        suggestions << new_suggestion
+      def initialize(file_path, suggestions)
+        @file_path = file_path
+        @suggestions = suggestions.sort_by(&:from_line_index)
+        @blob = suggestions.first&.diff_file&.new_blob
       end
 
       def line_conflict?
@@ -30,18 +27,8 @@ module Gitlab
         @new_content ||= _new_content
       end
 
-      def file_path
-        @file_path ||= _file_path
-      end
-
       private
 
-      attr_accessor :suggestions
-
-      def blob
-        first_suggestion&.diff_file&.new_blob
-      end
-
       def blob_data_lines
         blob.load_all_data!
         blob.data.lines
@@ -53,31 +40,19 @@ module Gitlab
 
       def _new_content
         current_content.tap do |content|
+          # NOTE: We need to cater for line number changes when the range is more than one line.
+          offset = 0
+
           suggestions.each do |suggestion|
-            range = line_range(suggestion)
+            range = line_range(suggestion, offset)
             content[range] = suggestion.to_content
+            offset += range.count - 1
           end
         end.join
       end
 
-      def line_range(suggestion)
-        suggestion.from_line_index..suggestion.to_line_index
-      end
-
-      def for_different_file?(suggestion)
-        file_path && file_path != suggestion_file_path(suggestion)
-      end
-
-      def suggestion_file_path(suggestion)
-        suggestion&.diff_file&.file_path
-      end
-
-      def first_suggestion
-        suggestions.first
-      end
-
-      def _file_path
-        suggestion_file_path(first_suggestion)
+      def line_range(suggestion, offset = 0)
+        (suggestion.from_line_index - offset)..(suggestion.to_line_index - offset)
       end
 
       def _line_conflict?

lib/gitlab/suggestions/suggestion_set.rb

@@ -26,10 +26,10 @@ module Gitlab
       end
 
       def actions
-        @actions ||= suggestions_per_file.map do |file_path, file_suggestion|
+        @actions ||= suggestions_per_file.map do |file_suggestion|
           {
             action: 'update',
-            file_path: file_path,
+            file_path: file_suggestion.file_path,
             content: file_suggestion.new_content
           }
         end
@@ -50,19 +50,9 @@ module Gitlab
       end
 
       def _suggestions_per_file
-        suggestions.each_with_object({}) do |suggestion, result|
-          file_path = suggestion.diff_file.file_path
-          file_suggestion = result[file_path] ||= FileSuggestion.new
-          file_suggestion.add_suggestion(suggestion)
-        end
-      end
-
-      def file_suggestions
-        suggestions_per_file.values
-      end
-
-      def first_file_suggestion
-        file_suggestions.first
+        suggestions
+          .group_by { |suggestion| suggestion.diff_file.file_path }
+          .map { |file_path, group| FileSuggestion.new(file_path, group) }
       end
 
       def _error_message
@@ -72,7 +62,7 @@ module Gitlab
           return message if message
         end
 
-        has_line_conflict = file_suggestions.any? do |file_suggestion|
+        has_line_conflict = suggestions_per_file.any? do |file_suggestion|
           file_suggestion.line_conflict?
         end
 

spec/lib/gitlab/suggestions/suggestion_set_spec.rb

@@ -87,11 +87,10 @@ describe Gitlab::Suggestions::SuggestionSet do
     it 'returns an array of hashes with proper key/value pairs' do
       first_action = suggestion_set.actions.first
 
-      file_path, file_suggestion = suggestion_set
-                                     .send(:suggestions_per_file).first
+      file_suggestion = suggestion_set.send(:suggestions_per_file).first
 
       expect(first_action[:action]).to be('update')
-      expect(first_action[:file_path]).to eq(file_path)
+      expect(first_action[:file_path]).to eq(file_suggestion.file_path)
       expect(first_action[:content]).to eq(file_suggestion.new_content)
     end
   end