Reuse default generated snippet name

app/models/snippet_repository.rb

@@ -48,15 +48,27 @@ class SnippetRepository < ApplicationRecord
     next_index = get_last_empty_file_index + 1
 
     files.each do |file_entry|
+      file_entry[:file_path] = file_path_for(file_entry, next_index) { next_index += 1 }
       file_entry[:action] = infer_action(file_entry) unless file_entry[:action]
-
-      if file_entry[:file_path].blank?
-        file_entry[:file_path] = build_empty_file_name(next_index)
-        next_index += 1
-      end
     end
   end
 
+  def file_path_for(file_entry, next_index)
+    return file_entry[:file_path] if file_entry[:file_path].present?
+    return file_entry[:previous_path] if reuse_previous_path?(file_entry)
+
+    build_empty_file_name(next_index).tap { yield }
+  end
+
+  # If the user removed the file_path and the previous_path
+  # matches the EMPTY_FILE_PATTERN, we don't need to
+  # rename the file and build a new empty file name,
+  # we can just reuse the existing file name
+  def reuse_previous_path?(file_entry)
+    file_entry[:file_path].blank? &&
+      EMPTY_FILE_PATTERN.match?(file_entry[:previous_path])
+  end
+
   def infer_action(file_entry)
     return :create if file_entry[:previous_path].blank?
 

changelogs/unreleased/fj-reuse-default-snippet-name.yml

+---
+title: Reuse default generated snippet file name in repository
+merge_request: 27673
+author:
+type: fixed

spec/models/snippet_repository_spec.rb

@@ -140,6 +140,41 @@ describe SnippetRepository do
     let_it_be(:named_snippet) { { file_path: 'fee.txt', content: 'bar', action: :create } }
     let_it_be(:unnamed_snippet) { { file_path: '', content: 'dummy', action: :create } }
 
+    context 'when existing file has a default name' do
+      let(:default_name) { 'snippetfile1.txt' }
+      let(:new_file) { { file_path: '', content: 'bar' } }
+      let(:existing_file) { { previous_path: default_name, file_path: '', content: 'new_content' } }
+
+      before do
+        expect(blob_at(snippet, default_name)).to be_nil
+
+        snippet_repository.multi_files_action(user, [new_file], commit_opts)
+
+        expect(blob_at(snippet, default_name)).to be
+      end
+
+      it 'reuses the existing file name' do
+        snippet_repository.multi_files_action(user, [existing_file], commit_opts)
+
+        blob = blob_at(snippet, default_name)
+        expect(blob.data).to eq existing_file[:content]
+      end
+    end
+
+    context 'when file name consists of one or several whitespaces' do
+      let(:default_name) { 'snippetfile1.txt' }
+      let(:new_file) { { file_path: ' ', content: 'bar' } }
+
+      it 'assigns a new name to the file' do
+        expect(blob_at(snippet, default_name)).to be_nil
+
+        snippet_repository.multi_files_action(user, [new_file], commit_opts)
+
+        blob = blob_at(snippet, default_name)
+        expect(blob.data).to eq new_file[:content]
+      end
+    end
+
     context 'when some files are not named' do
       let(:data) { [named_snippet] + Array.new(2) { unnamed_snippet.clone } }