1 files changed, 35 insertions, 0 deletions
diff --git a/spec/lib/gitlab/word_diff/positions_counter_spec.rb b/spec/lib/gitlab/word_diff/positions_counter_spec.rb
new file mode 100644
index 00000000000..e2c246f6801
--- /dev/null
+++ b/spec/lib/gitlab/word_diff/positions_counter_spec.rb
@@ -0,0 +1,35 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Gitlab::WordDiff::PositionsCounter do
+  subject(:counter) { described_class.new }
+
+  describe 'Initial state' do
+    it 'starts with predefined values' do
+      expect(counter.pos_old).to eq(1)
+      expect(counter.pos_new).to eq(1)
+      expect(counter.line_obj_index).to eq(0)
+    end
+  end
+
+  describe '#increase_pos_num' do
+    it 'increases old and new positions' do
+      expect { counter.increase_pos_num }.to change { counter.pos_old }.from(1).to(2)
+                                               .and change { counter.pos_new }.from(1).to(2)
+    end
+  end
+
+  describe '#increase_obj_index' do
+    it 'increases object index' do
+      expect { counter.increase_obj_index }.to change { counter.line_obj_index }.from(0).to(1)
+    end
+  end
+
+  describe '#set_pos_num' do
+    it 'sets old and new positions' do
+      expect { counter.set_pos_num(old: 10, new: 12) }.to change { counter.pos_old }.from(1).to(10)
+                                                            .and change { counter.pos_new }.from(1).to(12)
+    end
+  end
+end