1 files changed, 98 insertions, 0 deletions
diff --git a/spec/lib/gitlab/untrusted_regexp_spec.rb b/spec/lib/gitlab/untrusted_regexp_spec.rb
new file mode 100644
index 00000000000..bed58d407ef
--- /dev/null
+++ b/spec/lib/gitlab/untrusted_regexp_spec.rb
@@ -0,0 +1,98 @@
+require 'spec_helper'
+
+describe Gitlab::UntrustedRegexp do
+  describe '#initialize' do
+    subject { described_class.new(pattern) }
+
+    context 'invalid regexp' do
+      let(:pattern) { '[' }
+
+      it { expect { subject }.to raise_error(RegexpError) }
+    end
+  end
+
+  describe '#replace_all' do
+    it 'replaces all instances of the match in a string' do
+      result = described_class.new('foo').replace_all('foo bar foo', 'oof')
+
+      expect(result).to eq('oof bar oof')
+    end
+  end
+
+  describe '#replace' do
+    it 'replaces the first instance of the match in a string' do
+      result = described_class.new('foo').replace('foo bar foo', 'oof')
+
+      expect(result).to eq('oof bar foo')
+    end
+  end
+
+  describe '#===' do
+    it 'returns true for a match' do
+      result = described_class.new('foo') === 'a foo here'
+
+      expect(result).to be_truthy
+    end
+
+    it 'returns false for no match' do
+      result = described_class.new('foo') === 'a bar here'
+
+      expect(result).to be_falsy
+    end
+  end
+
+  describe '#scan' do
+    subject { described_class.new(regexp).scan(text) }
+    context 'malicious regexp' do
+      let(:text) { malicious_text }
+      let(:regexp) { malicious_regexp }
+
+      include_examples 'malicious regexp'
+    end
+
+    context 'empty regexp' do
+      let(:regexp) { '' }
+      let(:text) { 'foo' }
+
+      it 'returns an array of nil matches' do
+        is_expected.to eq([nil, nil, nil, nil])
+      end
+    end
+
+    context 'empty capture group regexp' do
+      let(:regexp) { '()' }
+      let(:text) { 'foo' }
+
+      it 'returns an array of nil matches in an array' do
+        is_expected.to eq([[nil], [nil], [nil], [nil]])
+      end
+    end
+
+    context 'no capture group' do
+      let(:regexp) { '.+' }
+      let(:text) { 'foo' }
+
+      it 'returns the whole match' do
+        is_expected.to eq(['foo'])
+      end
+    end
+
+    context 'one capture group' do
+      let(:regexp) { '(f).+' }
+      let(:text) { 'foo' }
+
+      it 'returns the captured part' do
+        is_expected.to eq([%w[f]])
+      end
+    end
+
+    context 'two capture groups' do
+      let(:regexp) { '(f).(o)' }
+      let(:text) { 'foo' }
+
+      it 'returns the captured parts' do
+        is_expected.to eq([%w[f o]])
+      end
+    end
+  end
+end