1 files changed, 86 insertions, 0 deletions
diff --git a/spec/lib/gitlab/checks/file_size_check/allow_existing_oversized_blobs_spec.rb b/spec/lib/gitlab/checks/file_size_check/allow_existing_oversized_blobs_spec.rb
new file mode 100644
index 00000000000..3b52d2e1364
--- /dev/null
+++ b/spec/lib/gitlab/checks/file_size_check/allow_existing_oversized_blobs_spec.rb
@@ -0,0 +1,86 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Gitlab::Checks::FileSizeCheck::AllowExistingOversizedBlobs, feature_category: :source_code_management do
+  subject { checker.find }
+
+  let_it_be(:project) { create(:project, :public, :repository) }
+  let(:checker) do
+    described_class.new(
+      project: project,
+      changes: changes,
+      file_size_limit_megabytes: 1)
+  end
+
+  describe '#find' do
+    let(:branch_name) { SecureRandom.uuid }
+    let(:other_branch_name) { SecureRandom.uuid }
+    let(:filename) { 'log.log' }
+    let(:create_file) do
+      project.repository.create_file(
+        project.owner,
+        filename,
+        initial_contents,
+        branch_name: branch_name,
+        message: 'whatever'
+      )
+    end
+
+    let(:changed_ref) do
+      project.repository.update_file(
+        project.owner,
+        filename,
+        changed_contents,
+        branch_name: other_branch_name,
+        start_branch_name: branch_name,
+        message: 'whatever'
+      )
+    end
+
+    let(:changes) { [oldrev: create_file, newrev: changed_ref] }
+
+    before do
+      # set up a branch
+      create_file
+
+      # branch off that branch
+      changed_ref
+
+      # delete stuff so it can be picked up by new_blobs
+      project.repository.delete_branch(other_branch_name)
+    end
+
+    context 'when changing from valid to oversized' do
+      let(:initial_contents) { 'a' }
+      let(:changed_contents) { 'a' * ((2**20) + 1) } # 1 MB + 1 byte
+
+      it 'returns an array with blobs that became oversized' do
+        blob = subject.first
+        expect(blob.path).to eq(filename)
+        expect(subject).to contain_exactly(blob)
+      end
+    end
+
+    context 'when changing from oversized to oversized' do
+      let(:initial_contents) { 'a' * ((2**20) + 1) } # 1 MB + 1 byte
+      let(:changed_contents) { 'a' * ((2**20) + 2) } # 1 MB + 1 byte
+
+      it { is_expected.to be_blank }
+    end
+
+    context 'when changing from oversized to valid' do
+      let(:initial_contents) { 'a' * ((2**20) + 1) } # 1 MB + 1 byte
+      let(:changed_contents) { 'aa' }
+
+      it { is_expected.to be_blank }
+    end
+
+    context 'when changing from valid to valid' do
+      let(:initial_contents) { 'abc' }
+      let(:changed_contents) { 'def' }
+
+      it { is_expected.to be_blank }
+    end
+  end
+end