Log a warning message when some message strings are too long. (#5)

* Log a warning message when some message strings are too long.

Some title and subtitle fields can be longer than the soft limit given in the
documentation. They will be truncated when displayed on Messenger, and the Send
API does not raise any error.

* Add pytest-catchlog to requirements

fbmessenger/elements.py

@@ -1,3 +1,12 @@
+from __future__ import absolute_import
+
+import logging
+
+from .error_messages import CHARACTER_LIMIT_MESSAGE
+
+logger = logging.getLogger(__name__)
+
+
 class Text(object):
     def __init__(self, text, quick_replies=None):
         self.text = text
@@ -39,7 +48,8 @@ def __init__(self, button_type, title=None, url=None,
         if webview_height_ratio and webview_height_ratio not in self.WEBVIEW_HEIGHT_RATIOS:
             raise ValueError('Invalid webview_height_ratio provided.')
         if title and len(title) > 20:
-            raise ValueError('Title cannot be longer 20 characters.')
+            logger.warning(CHARACTER_LIMIT_MESSAGE.format(field='Title',
+                                                          maxsize=20))
 
         self.button_type = button_type
         self.title = title
@@ -95,9 +105,8 @@ def title(self):
     @title.setter
     def title(self, title):
         if len(title) > 80:
-            raise ValueError(
-                'Title cannot be longer 80 characters'
-            )
+            logger.warning(CHARACTER_LIMIT_MESSAGE.format(field='Title',
+                                                          maxsize=80))
         self._title = title
 
     @property
@@ -107,7 +116,8 @@ def subtitle(self):
     @subtitle.setter
     def subtitle(self, subtitle):
         if subtitle is not None and len(subtitle) > 80:
-            raise ValueError('Subtitle cannot be longer 80 characters')
+            logger.warning(CHARACTER_LIMIT_MESSAGE.format(field='Subtitle',
+                                                          maxsize=80))
         self._subtitle = subtitle
 
     def to_dict(self):

fbmessenger/error_messages.py

@@ -0,0 +1,2 @@
+CHARACTER_LIMIT_MESSAGE = ("{field} is longer than {maxsize} characters, "
+                           "it will be truncated when displayed.")

fbmessenger/quick_replies.py

@@ -1,3 +1,12 @@
+from __future__ import absolute_import
+
+import logging
+
+from .error_messages import CHARACTER_LIMIT_MESSAGE
+
+logger = logging.getLogger(__name__)
+
+
 class QuickReply(object):
 
     CONTENT_TYPES = [
@@ -12,7 +21,8 @@ def __init__(self, title=None, payload=None, image_url=None, content_type=None):
         if content_type not in self.CONTENT_TYPES:
             raise ValueError('Invalid content_type provided.')
         if title and len(title) > 20:
-            raise ValueError('Title cannot be longer 20 characters.')
+            logger.warning(CHARACTER_LIMIT_MESSAGE.format(field='Title',
+                                                          maxsize=20))
         if payload and len(payload) > 1000:
             raise ValueError('Payload cannot be longer 1000 characters.')
 

requirements.txt

@@ -5,6 +5,7 @@ pbr==1.9.1
 py==1.4.31
 pyandoc==0.2.0
 pytest==2.8.7
+pytest-catchlog==1.2.2
 pytest-cov==2.2.1
 requests==2.10.0
 six==1.10.0

setup.py

@@ -34,6 +34,7 @@
     'pytest',
     'coverage',
     'pytest-cov',
+    'pytest-catchlog',
     'responses'
 ]
 

tests/test_elements.py

@@ -1,7 +1,10 @@
+import logging
+
 import pytest
 
 from fbmessenger import elements
 from fbmessenger import quick_replies
+from fbmessenger.error_messages import CHARACTER_LIMIT_MESSAGE
 
 
 class TestElements:
@@ -71,12 +74,15 @@ def test_url_button(self):
         }
         assert expected == res.to_dict()
 
-    def test_button_with_title_over_limit(self):
-        with pytest.raises(ValueError) as err:
-            res = elements.Button(button_type='web_url', title='This button text is over the limit',
+    def test_button_with_title_over_limit(self, caplog):
+        with caplog.at_level(logging.WARNING, logger='fbmessenger.elements'):
+            res = elements.Button(button_type='web_url',
+                                  title='This button text is over the limit',
                                   url='http://facebook.com')
             res.to_dict()
-        assert str(err.value) == 'Title cannot be longer 20 characters.'
+            assert caplog.record_tuples == [
+                ('fbmessenger.elements', logging.WARNING,
+                  CHARACTER_LIMIT_MESSAGE.format(field='Title', maxsize=20))]
 
     def test_element(self):
         btn = elements.Button(button_type='web_url', title='Web button', url='http://facebook.com')
@@ -120,8 +126,8 @@ def test_button_webview_height_ratio_validation(self):
             )
         assert str(err.value) == 'Invalid webview_height_ratio provided.'
 
-    def test_element_title_validation(self):
-        with pytest.raises(ValueError) as err:
+    def test_element_title_validation(self, caplog):
+        with caplog.at_level(logging.WARNING, logger='fbmessenger.elements'):
             btn = elements.Button(button_type='web_url', title='Web button', url='http://facebook.com')
             res = elements.Element(
                 title='The title is too long and should throw an error.'
@@ -134,10 +140,12 @@ def test_element_title_validation(self):
                 ]
             )
             res.to_dict()
-        assert str(err.value) == 'Title cannot be longer 80 characters'
+            assert caplog.record_tuples == [
+                ('fbmessenger.elements', logging.WARNING,
+                  CHARACTER_LIMIT_MESSAGE.format(field='Title', maxsize=80))]
 
-    def test_element_subtitle_validation(self):
-        with pytest.raises(ValueError) as err:
+    def test_element_subtitle_validation(self, caplog):
+        with caplog.at_level(logging.WARNING, logger='fbmessenger.elements'):
             btn = elements.Button(button_type='web_url', title='Web button', url='http://facebook.com')
             res = elements.Element(
                 title='Title',
@@ -150,7 +158,9 @@ def test_element_subtitle_validation(self):
                 ]
             )
             res.to_dict()
-        assert str(err.value) == 'Subtitle cannot be longer 80 characters'
+            assert caplog.record_tuples == [
+                ('fbmessenger.elements', logging.WARNING,
+                  CHARACTER_LIMIT_MESSAGE.format(field='Subtitle', maxsize=80))]
 
     def test_adjustment(self):
         res = elements.Adjustment(name='discount', amount=1)

tests/test_quick_replies.py

@@ -1,6 +1,9 @@
+import logging
+
 import pytest
 
 from fbmessenger import quick_replies
+from fbmessenger.error_messages import CHARACTER_LIMIT_MESSAGE
 
 
 class TestQuickReplies:
@@ -19,11 +22,13 @@ def test_quick_reply(self):
         }
         assert expected == res.to_dict()
 
-    def test_quick_reply_title_too_long(self):
-        with pytest.raises(ValueError) as err:
+    def test_quick_reply_title_too_long(self, caplog):
+        with caplog.at_level(logging.WARNING, logger='fbmessenger.elements'):
             quick_replies.QuickReply(title='Title is over the 20 character limit',
                                            payload='QR payload')
-        assert str(err.value) == 'Title cannot be longer 20 characters.'
+            assert caplog.record_tuples == [
+                ('fbmessenger.quick_replies', logging.WARNING,
+                  CHARACTER_LIMIT_MESSAGE.format(field='Title', maxsize=20))]
 
     def test_quick_reply_payload_too_long(self):
         payload = 'x' * 1001