1 files changed, 97 insertions, 0 deletions
diff --git a/spec/scripts/setup/find_jh_branch_spec.rb b/spec/scripts/setup/find_jh_branch_spec.rb
new file mode 100644
index 00000000000..dfc3601ffa9
--- /dev/null
+++ b/spec/scripts/setup/find_jh_branch_spec.rb
@@ -0,0 +1,97 @@
+# frozen_string_literal: true
+
+require 'fast_spec_helper'
+
+# NOTE: Under the context of fast_spec_helper, when we `require 'gitlab'`
+# we do not load the Gitlab client, but our own Gitlab module.
+# Keep this in mind and just stub anything which might touch it!
+require_relative '../../../scripts/setup/find-jh-branch'
+
+RSpec.describe FindJhBranch do
+  subject { described_class.new }
+
+  describe '#run' do
+    context 'when it is not a merge request' do
+      before do
+        expect(subject).to receive(:merge_request?).and_return(false)
+      end
+
+      it 'returns JH_DEFAULT_BRANCH' do
+        expect(subject.run).to eq(described_class::JH_DEFAULT_BRANCH)
+      end
+    end
+
+    context 'when it is a merge request' do
+      let(:branch_name) { 'branch-name' }
+      let(:jh_branch_name) { 'branch-name-jh' }
+      let(:default_branch) { 'main' }
+      let(:merge_request) { double(target_branch: target_branch) }
+      let(:target_branch) { default_branch }
+
+      before do
+        expect(subject).to receive(:merge_request?).and_return(true)
+
+        expect(subject)
+          .to receive(:branch_exist?)
+          .with(described_class::JH_PROJECT_PATH, jh_branch_name)
+          .and_return(jh_branch_exist)
+
+        allow(subject).to receive(:ref_name).and_return(branch_name)
+        allow(subject).to receive(:default_branch).and_return(default_branch)
+        allow(subject).to receive(:merge_request).and_return(merge_request)
+      end
+
+      context 'when there is a corresponding JH branch' do
+        let(:jh_branch_exist) { true }
+
+        it 'returns the corresponding JH branch name' do
+          expect(subject.run).to eq(jh_branch_name)
+        end
+      end
+
+      context 'when there is no corresponding JH branch' do
+        let(:jh_branch_exist) { false }
+
+        it 'returns the default JH branch' do
+          expect(subject.run).to eq(described_class::JH_DEFAULT_BRANCH)
+        end
+
+        context 'when it is targeting a default branch' do
+          let(:target_branch) { '14-6-stable-ee' }
+          let(:jh_stable_branch_name) { '14-6-stable-jh' }
+
+          before do
+            expect(subject)
+              .to receive(:branch_exist?)
+              .with(described_class::JH_PROJECT_PATH, jh_stable_branch_name)
+              .and_return(jh_stable_branch_exist)
+          end
+
+          context 'when there is a corresponding JH stable branch' do
+            let(:jh_stable_branch_exist) { true }
+
+            it 'returns the corresponding JH stable branch' do
+              expect(subject.run).to eq(jh_stable_branch_name)
+            end
+          end
+
+          context 'when there is no corresponding JH stable branch' do
+            let(:jh_stable_branch_exist) { false }
+
+            it "raises #{described_class::BranchNotFound}" do
+              expect { subject.run }.to raise_error(described_class::BranchNotFound)
+            end
+          end
+        end
+
+        context 'when it is not targeting the default branch' do
+          let(:target_branch) { default_branch.swapcase }
+
+          it 'returns the default JH branch' do
+            expect(subject.run).to eq(described_class::JH_DEFAULT_BRANCH)
+          end
+        end
+      end
+    end
+  end
+end