1 files changed, 21 insertions, 0 deletions
diff --git a/spec/bundler/bundler/ci_detector_spec.rb b/spec/bundler/bundler/ci_detector_spec.rb
new file mode 100644
index 0000000000..299d8005e8
--- /dev/null
+++ b/spec/bundler/bundler/ci_detector_spec.rb
@@ -0,0 +1,21 @@
+# frozen_string_literal: true
+
+RSpec.describe Bundler::CIDetector do
+  # This is properly tested in rubygems, under the name Gem::CIDetector
+  # But the test that confirms that our version _stays in sync_ with that version
+  # will live here.
+
+  it "stays in sync with the rubygems implementation" do
+    rubygems_implementation_path = File.join(git_root, "lib", "rubygems", "ci_detector.rb")
+    expect(File.exist?(rubygems_implementation_path)).to be_truthy
+    rubygems_code = File.read(rubygems_implementation_path)
+    denamespaced_rubygems_code = rubygems_code.sub("Gem", "NAMESPACE")
+
+    bundler_implementation_path = File.join(source_lib_dir, "bundler", "ci_detector.rb")
+    expect(File.exist?(bundler_implementation_path)).to be_truthy
+    bundler_code = File.read(bundler_implementation_path)
+    denamespaced_bundler_code = bundler_code.sub("Bundler", "NAMESPACE")
+
+    expect(denamespaced_bundler_code).to eq(denamespaced_rubygems_code)
+  end
+end