Add latest changes from gitlab-org/gitlab@13-9-stable-eev13.9.0-rc42

1 files changed, 77 insertions, 0 deletions

diff --git a/spec/lib/gitlab/diff/char_diff_spec.rb b/spec/lib/gitlab/diff/char_diff_spec.rb
new file mode 100644
index 00000000000..e4e2a3ba050
--- /dev/null
+++ b/spec/lib/gitlab/diff/char_diff_spec.rb
@@ -0,0 +1,77 @@
+# frozen_string_literal: true
+
+require 'fast_spec_helper'
+require 'diff_match_patch'
+
+RSpec.describe Gitlab::Diff::CharDiff do
+  let(:old_string) { "Helo \n Worlld" }
+  let(:new_string) { "Hello \n World" }
+
+  subject(:diff) { described_class.new(old_string, new_string) }
+
+  describe '#generate_diff' do
+    context 'when old string is nil' do
+      let(:old_string) { nil }
+
+      it 'does not raise an error' do
+        expect { subject.generate_diff }.not_to raise_error
+      end
+
+      it 'treats nil values as blank strings' do
+        changes = subject.generate_diff
+
+        expect(changes).to eq([
+          [:insert, "Hello \n World"]
+        ])
+      end
+    end
+
+    it 'generates an array of changes' do
+      changes = subject.generate_diff
+
+      expect(changes).to eq([
+        [:equal, "Hel"],
+        [:insert, "l"],
+        [:equal, "o \n Worl"],
+        [:delete, "l"],
+        [:equal, "d"]
+      ])
+    end
+  end
+
+  describe '#changed_ranges' do
+    subject { diff.changed_ranges }
+
+    context 'when old string is nil' do
+      let(:old_string) { nil }
+
+      it 'returns lists of changes' do
+        old_diffs, new_diffs = subject
+
+        expect(old_diffs).to eq([])
+        expect(new_diffs).to eq([0..12])
+      end
+    end
+
+    it 'returns ranges of changes' do
+      old_diffs, new_diffs = subject
+
+      expect(old_diffs).to eq([11..11])
+      expect(new_diffs).to eq([3..3])
+    end
+  end
+
+  describe '#to_html' do
+    it 'returns an HTML representation of the diff' do
+      subject.generate_diff
+
+      expect(subject.to_html).to eq(
+        '<span class="idiff">Hel</span>' \
+        '<span class="idiff addition">l</span>' \
+        "<span class=\"idiff\">o \n Worl</span>" \
+        '<span class="idiff deletion">l</span>' \
+        '<span class="idiff">d</span>'
+      )
+    end
+  end
+end