First draft of API to add items to a collection (#37222)

spec/requests/api/v1_alpha/collection_items_spec.rb

@@ -0,0 +1,55 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe 'Api::V1Alpha::CollectionItems', feature: :collections do
+  include_context 'with API authentication', oauth_scopes: 'read:collections write:collections'
+
+  describe 'POST /api/v1_alpha/collections/:collection_id/items' do
+    subject do
+      post "/api/v1_alpha/collections/#{collection.id}/items", headers: headers, params: params
+    end
+
+    let(:collection) { Fabricate(:collection, account: user.account) }
+    let(:params) { {} }
+
+    it_behaves_like 'forbidden for wrong scope', 'read'
+
+    context 'when user is owner of the collection' do
+      context 'with valid params' do
+        let(:other_account) { Fabricate(:account) }
+        let(:params) { { account_id: other_account.id } }
+
+        it 'creates a collection item and returns http success' do
+          expect do
+            subject
+          end.to change(collection.collection_items, :count).by(1)
+
+          expect(response).to have_http_status(200)
+        end
+      end
+
+      context 'with invalid params' do
+        it 'returns http unprocessable content' do
+          expect do
+            subject
+          end.to_not change(CollectionItem, :count)
+
+          expect(response).to have_http_status(422)
+        end
+      end
+    end
+
+    context 'when user is not the owner of the collection' do
+      let(:collection) { Fabricate(:collection) }
+      let(:other_account) { Fabricate(:account) }
+      let(:params) { { account_id: other_account.id } }
+
+      it 'returns http forbidden' do
+        subject
+
+        expect(response).to have_http_status(403)
+      end
+    end
+  end
+end