Detect Content Type of file uploaded in multipart/form-data request

Closes #271 #285 #398

This adds filename-based detection. It's still not possible to specify the
content type manually, though.

.gitignore

@@ -9,3 +9,4 @@ README.html
 htmlcov
 .idea
 .DS_Store
+.cache/

CHANGELOG.rst

@@ -8,6 +8,7 @@ This project adheres to `Semantic Versioning <http://semver.org/>`_.
 `1.0.0-dev`_ (Unreleased)
 -------------------------
 
+* Added ``Content-Type`` of files uploaded in ``multipart/form-data`` requests.
 * Changed the default color style back to``solarized`` as it supports
   both the light and dark terminal background mode.
 

httpie/input.py

@@ -605,9 +605,13 @@ class DataDict(RequestItemsDict):
 RequestItems = namedtuple('RequestItems',
                           ['headers', 'data', 'files', 'params'])
 
+
 def get_content_type(filename):
-    """Get content type for a filename in format appropriate for Content-Type
-    headers.
+    """
+    Return the content type for ``filename`` in format appropriate
+    for Content-Type headers, or ``None`` if the file type is unknown
+    to ``mimetypes``.
+
     """
     mime, encoding = mimetypes.guess_type(filename, strict=False)
     if mime:
@@ -616,6 +620,7 @@ def get_content_type(filename):
             content_type = '%s; charset=%s' % (mime, encoding)
         return content_type
 
+
 def parse_items(items,
                 headers_class=CaseInsensitiveDict,
                 data_class=OrderedDict,

tests/test_uploads.py

@@ -23,6 +23,7 @@ class TestMultipartFormDataFileUpload:
                ' filename="%s"' % os.path.basename(FILE_PATH) in r
         assert FILE_CONTENT in r
         assert '"foo": "bar"' in r
+        assert 'Content-Type: text/plain' in r
 
     def test_upload_multiple_fields_with_the_same_name(self, httpbin):
         r = http('--form', '--verbose', 'POST', httpbin.url + '/post',
@@ -34,6 +35,7 @@ class TestMultipartFormDataFileUpload:
         # Should be 4, but is 3 because httpbin
         # doesn't seem to support filed field lists
         assert r.count(FILE_CONTENT) in [3, 4]
+        assert r.count('Content-Type: text/plain') == 2
 
 
 class TestRequestBodyFromFilePath: