Properly handle Goodreads titles without covers

Add some unit test coverage while we're at it.

bibliophile/goodreads.py

@@ -43,6 +43,10 @@
 def higher_quality_cover(image_url):
     """ Modify a book cover to be higher quality. """
     parsed = urlparse.urlparse(image_url)
+    if parsed.path.startswith('/assets/nophoto'):
+        # No known cover for this book! Just return the "no photo" image
+        return image_url
+
     match = GOODREADS_IMAGE_REGEX.match(parsed.path)
     if not match:
         logger.warning("Goodreads image format changed! (%s) "

bibliophile/syndetics.py

@@ -17,7 +17,7 @@ def higher_quality_cover(image_url):
     metadata, are left unmodified.
 
     Documentation on the URL scheme can be found in the 'Syndetics Starter Page':
-    https://developers.exlibrisgroup.com/resources/voyager/code_contributions/SyndeticsStarterDocument.pdf
+    https://developers.exlibrisgroup.com/wp-content/uploads/2010/05/SyndeticsStarterDocument.pdf
     """
     parsed = urlparse.urlparse(image_url)
     params = urlparse.parse_qs(parsed.query)

bibliophile/tests/test_goodreads.py

@@ -0,0 +1,26 @@
+import unittest
+
+from ..goodreads import higher_quality_cover
+
+
+class CoverImageTests(unittest.TestCase):
+    def test_nophoto_url_unchanged(self):
+        """ We handle Goodreads' "nophoto" URL. """
+        nophoto = ("https://www.goodreads.com/"
+                   "assets/nophoto/book/111x148-bcc042a9c91a29c1d680899eff700a03.png")
+        image_url = higher_quality_cover(nophoto)
+        self.assertEqual(image_url, nophoto)
+
+    def test_medium_photo_enlarged(self):
+        """ We can produce higher-quality images for medium-sized cover. """
+        self.assertEqual(
+            higher_quality_cover('https://images.gr-assets.com/books/1436292289m/25663961.jpg'),
+            'https://images.gr-assets.com/books/1436292289l/25663961.jpg'
+        )
+
+    def test_small_photo_enlarged(self):
+        """ We can produce higher-quality images for a small-sized cover. """
+        self.assertEqual(
+            higher_quality_cover('https://images.gr-assets.com/books/1550917827s/1202.jpg'),
+            'https://images.gr-assets.com/books/1550917827l/1202.jpg'
+        )

bibliophile/tests/test_syndetics.py

@@ -4,9 +4,17 @@
 
 
 class SyndeticsTest(unittest.TestCase):
-    def test_nophoto_url_unchanged(self):
-        """ We handle Goodreads' "nophoto" URL. """
-        nophoto = ("https://www.goodreads.com/"
-                   "assets/nophoto/book/111x148-bcc042a9c91a29c1d680899eff700a03.png")
-        image_url = higher_quality_cover(nophoto)
-        self.assertEqual(image_url, nophoto)
+    def test_unrecognize_images_returned_as_is(self):
+        """ If there's no ISBN in the URL, we don't modify the URL. """
+        img_url = 'https://secure.syndetics.com/index.aspx?fake_url'
+        self.assertEqual(higher_quality_cover(img_url), img_url)
+
+    def test_small_gif_becomes_large_jpeg(self):
+        """ We transform small images to larger ones. """
+        base_url = 'https://secure.syndetics.com/index.aspx'
+        self.assertEqual(
+            higher_quality_cover(
+                f'{base_url}?isbn=9780140449266/SC.GIF&client=sfpl&type=xw12&oclc='
+            ),
+            f'{base_url}?isbn=9780140449266%2FLC.jpg&client=sfpl&type=xw12'
+        )