Refactored --pretty and added tests.

 #16

httpie/httpie.py

@@ -16,6 +16,7 @@
 SEP_DATA = '='
 TYPE_FORM = 'application/x-www-form-urlencoded; charset=utf-8'
 TYPE_JSON = 'application/json; charset=utf-8'
+PRETTIFY_STDOUT_TTY_ONLY = object()
 
 
 KeyValue = namedtuple('KeyValue', ['key', 'value', 'sep'])
@@ -57,8 +58,15 @@ def __call__(self, string):
 parser.add_argument('--traceback', action='store_true', default=False,
                   help='Print a full exception traceback should one'
                        ' be raised by `requests`.')
-parser.add_argument('--ugly', '-u', help='Do not prettify the response.',
-                     dest='prettify', action='store_false', default=True)
+group_pretty = parser.add_mutually_exclusive_group(required=False)
+group_pretty.add_argument('--pretty', '-p', dest='prettify', action='store_true',
+                          default=PRETTIFY_STDOUT_TTY_ONLY,
+                          help='If stdout is a terminal, '
+                               ' the response is prettified by default (colorized and'
+                               ' indented if it is JSON). This flag ensures'
+                               ' prettifying even when stdout is redirected.')
+group_pretty.add_argument('--ugly', '-u', help='Do not prettify the response.',
+                          dest='prettify', action='store_false')
 group_only = parser.add_mutually_exclusive_group(required=False)
 group_only.add_argument('--headers', '-t', dest='print_body',
                         action='store_false', default=True,
@@ -70,8 +78,6 @@ def __call__(self, string):
                     choices=pretty.AVAILABLE_STYLES,
                     help='Output coloring style, one of %s. Defaults to solarized.'
                           % ', '.join(sorted(pretty.AVAILABLE_STYLES)))
-parser.add_argument('--pretty', '-p', help='Force pretty print.',
-                     dest='force_pretty', action='store_true', default=False)
 
 # ``requests.request`` keyword arguments.
 parser.add_argument('--auth', '-a', help='username:password',
@@ -96,13 +102,13 @@ def __call__(self, string):
                          ' (Use socket.setdefaulttimeout() as fallback).')
 
 # Positional arguments.
-parser.add_argument('method',
+parser.add_argument('method', metavar='METHOD',
                     help='HTTP method to be used for the request'
                          ' (GET, POST, PUT, DELETE, PATCH, ...).')
 parser.add_argument('url', metavar='URL',
                     help='Protocol defaults to http:// if the'
                          ' URL does not include it.')
-parser.add_argument('items', metavar='item', nargs='*',
+parser.add_argument('items', nargs='*',
                     type=KeyValueType([SEP_COMMON, SEP_DATA]),
                     help='HTTP header (key:value) or data field (key=value)')
 
@@ -114,8 +120,8 @@ def main(args=None,
          stdout_isatty=sys.stdout.isatty()):
 
     args = parser.parse_args(args if args is not None else sys.argv[1:])
-    is_pretty = args.force_pretty or stdout_isatty
-
+    do_prettify = (args.prettify is True or
+                     (args.prettify == PRETTIFY_STDOUT_TTY_ONLY and stdout_isatty))
     # Parse request headers and data from the command line.
     headers = CaseInsensitiveDict()
     headers['User-Agent'] = DEFAULT_UA
@@ -177,7 +183,7 @@ def main(args=None,
         response.content.decode(encoding) if response.content else u''
     )
 
-    if args.prettify and is_pretty:
+    if do_prettify:
         prettify = pretty.PrettyHttp(args.style)
         if args.print_headers:
             status_line = prettify.headers(status_line).strip()

tests.py

@@ -1,13 +1,20 @@
+from functools import partial
 import unittest
 from StringIO import StringIO
 from httpie import httpie
 
 
+TERMINAL_COLOR_END = '\x1b[39m'
+
+
 def http(*args, **kwargs):
-    stdout = StringIO()
-    httpie.main(args=args, stdout=stdout,
-                stdin_isatty=True,
-                stdout_isatty=False)
+    http_kwargs = {
+        'stdin_isatty': True,
+        'stdout_isatty': False
+    }
+    http_kwargs.update(kwargs)
+    stdout = http_kwargs.setdefault('stdout', StringIO())
+    httpie.main(args=args, **http_kwargs)
     return stdout.getvalue()
 
 
@@ -32,5 +39,25 @@ def test_headers(self):
         self.assertIn('"Foo": "bar"', response)
 
 
+class TestPrettyFlag(unittest.TestCase):
+    """Test the --pretty / --ugly flag handling."""
+
+    def test_pretty_enabled_by_default(self):
+        r = http('GET', 'http://httpbin.org/get', stdout_isatty=True)
+        self.assertIn(TERMINAL_COLOR_END, r)
+
+    def test_pretty_enabled_by_default_unless_stdin_redirected(self):
+        r = http('GET', 'http://httpbin.org/get', stdout_isatty=False)
+        self.assertNotIn(TERMINAL_COLOR_END, r)
+
+    def test_force_pretty(self):
+        r = http('GET', '--pretty', 'http://httpbin.org/get', stdout_isatty=False)
+        self.assertIn(TERMINAL_COLOR_END, r)
+
+    def test_force_ugly(self):
+        r = http('GET', '--ugly', 'http://httpbin.org/get', stdout_isatty=True)
+        self.assertNotIn(TERMINAL_COLOR_END, r)
+
+
 if __name__ == '__main__':
     unittest.main()