Adds a unit test for the unsplash engine

tests/unit/engines/test_unsplash.py

@@ -0,0 +1,38 @@
+from collections import defaultdict
+import mock
+from searx.testing import SearxTestCase
+from searx.engines import unsplash
+
+
+class TestUnsplashEngine(SearxTestCase):
+    def test_request(self):
+        query = 'penguin'
+        _dict = defaultdict(dict)
+        _dict['pageno'] = 1
+        params = unsplash.request(query, _dict)
+
+        self.assertTrue('url' in params)
+        self.assertTrue(query in params['url'])
+
+    def test_response(self):
+        resp = mock.Mock(text='{}')
+        result = unsplash.response(resp)
+        self.assertEqual([], result)
+
+        resp.text = '{"results": []}'
+        result = unsplash.response(resp)
+        self.assertEqual([], result)
+
+        # Sourced from https://unsplash.com/napi/search/photos?query=penguin&xp=&per_page=20&page=2
+        with open('./tests/unit/engines/unsplash_fixture.json') as fixture:
+            resp.text = fixture.read()
+
+        result = unsplash.response(resp)
+        self.assertEqual(len(result), 2)
+        self.assertEqual(result[0]['title'], 'low angle photography of swimming penguin')
+        self.assertEqual(result[0]['url'], 'https://unsplash.com/photos/FY8d721UO_4')
+        self.assertEqual(result[0]['thumbnail_src'], 'https://images.unsplash.com/photo-1523557148507-1b77641c7e7c?ixlib=rb-0.3.5&q=80\
+&fm=jpg&crop=entropy&cs=tinysrgb&w=200&fit=max&ixid=eyJhcHBfaWQiOjEyMDd9&s=a9b9e56e63efc6f4611a87ce7e9a48f8')
+        self.assertEqual(result[0]['img_src'], 'https://images.unsplash.com/photo-1523557148507-1b77641c7e7c?ixlib=rb-0.3.5\
+&ixid=eyJhcHBfaWQiOjEyMDd9&s=095c5fc319c5a77c705f49ad63e0f195')
+        self.assertEqual(result[0]['content'], '')