Use Magic to resolve content-type on upload (#121)

Performs conditional import of magic with hinting about
python-magic-bin on Mac and Windows

Signed-off-by: Robert Wikman <[email protected]>

.travis.yml

@@ -7,7 +7,7 @@ python:
   - "3.6"
 # command to install dependencies
 install:
-  - pip install pysnow requests httpretty oauthlib requests_oauthlib coverage python-coveralls nose ijson six pytz
+  - pip install pysnow requests httpretty oauthlib requests_oauthlib coverage python-coveralls nose ijson six pytz python-magic
 # command to run tests
 script:
   - nosetests --with-coverage --cover-package=pysnow --cover-erase

pysnow/__init__.py

@@ -7,13 +7,13 @@
 from .params_builder import ParamsBuilder
 
 __author__ = "Robert Wikman <[email protected]>"
-__version__ = "0.7.8"
+__version__ = "0.7.9"
 
 # Set default logging handler to avoid "No handler found" warnings.
 import logging
 try:  # Python 2.7+
     from logging import NullHandler
-except ImportError:
+except ImportError:  # pragma: no cover
     class NullHandler(logging.Handler):
         def emit(self, record):
             pass

pysnow/attachment.py

@@ -1,6 +1,16 @@
 # -*- coding: utf-8 -*-
 
 import os
+import warnings
+
+try:
+    import magic
+    HAS_MAGIC = True
+except ImportError:  # pragma: no cover
+    HAS_MAGIC = False
+    warnings.warn("Missing the python-magic library; attachment content-type will be set to text/plain. "
+                  "Try installing the python-magic-bin package if running on Mac or Windows")
+
 from pysnow.exceptions import InvalidUsage
 
 
@@ -59,7 +69,7 @@ def upload(self, sys_id, file_path, name=None, multipart=False):
             headers["Content-Type"] = "multipart/form-data"
             path_append = '/upload'
         else:
-            headers["Content-Type"] = "text/plain"
+            headers["Content-Type"] = magic.from_file(file_path, mime=True) if HAS_MAGIC else "text/plain"
             path_append = '/file'
 
         return resource.request(method='POST', data=data, headers=headers, path_append=path_append)

setup.py

@@ -26,7 +26,16 @@ def get_version():
         version=get_version(),
         description='ServiceNow HTTP client library',
         long_description=readme.read(),
-        install_requires=['requests', 'oauthlib', 'requests_oauthlib', 'httpretty', 'six', 'ijson', 'pytz'],
+        install_requires=[
+            'requests',
+            'oauthlib',
+            'python-magic',
+            'requests_oauthlib',
+            'httpretty',
+            'six',
+            'ijson',
+            'pytz'
+        ],
         author='Robert Wikman',
         author_email='[email protected]',
         maintainer='Robert Wikman',