1 files changed, 42 insertions, 0 deletions
diff --git a/spec/lib/csv_builders/stream_spec.rb b/spec/lib/csv_builders/stream_spec.rb
new file mode 100644
index 00000000000..204baf965d0
--- /dev/null
+++ b/spec/lib/csv_builders/stream_spec.rb
@@ -0,0 +1,42 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe CsvBuilders::Stream do
+  let(:event_1) { double(title: 'Added salt', description: 'A teaspoon') }
+  let(:event_2) { double(title: 'Added sugar', description: 'Just a pinch') }
+  let(:fake_relation) { FakeRelation.new([event_1, event_2]) }
+
+  subject(:builder) { described_class.new(fake_relation, 'Title' => 'title', 'Description' => 'description') }
+
+  describe '#render' do
+    before do
+      stub_const('FakeRelation', Array)
+
+      FakeRelation.class_eval do
+        def find_each(&block)
+          each(&block)
+        end
+      end
+    end
+
+    it 'returns a lazy enumerator' do
+      expect(builder.render).to be_an(Enumerator::Lazy)
+    end
+
+    it 'returns all rows up to default max value' do
+      expect(builder.render.to_a).to eq([
+        "Title,Description\n",
+        "Added salt,A teaspoon\n",
+        "Added sugar,Just a pinch\n"
+      ])
+    end
+
+    it 'truncates to max rows' do
+      expect(builder.render(1).to_a).to eq([
+        "Title,Description\n",
+        "Added salt,A teaspoon\n"
+      ])
+    end
+  end
+end