Use a tempfile instead of a StringIO object

This provides a socket.fileno(), so
libraries that call select.poll() work properly.
Also supports mocking huge responses larger than memory, if needed.

httpretty/core.py

@@ -36,6 +36,7 @@ import traceback
 import json
 import contextlib
 import threading
+import tempfile
 
 
 from .compat import (
@@ -236,10 +237,17 @@ class HTTPrettyRequestEmpty(object):
     headers = EmptyRequestHeaders()
 
 
-class FakeSockFile(StringIO):
+class FakeSockFile(object):
+    def __init__(self):
+        self.file = tempfile.TemporaryFile()
+        self._fileno = self.file.fileno()
     def close(self):
         self.socket.close()
-        StringIO.close(self)
+        self.file.close()
+    def fileno(self):
+        return self._fileno
+    def __getattr__(self, name):
+        return getattr(self.file, name)
 
 
 class FakeSSLSocket(object):
@@ -322,6 +330,11 @@ class fakesock(object):
                 else:
                     raise UnmockedError()
 
+        def fileno(self):
+            if self.truesock:
+                return self.truesock.fileno()
+            return self.fd.fileno()
+
         def close(self):
             if not (self.is_http and self._closed):
                 if self.truesock:
@@ -329,7 +342,7 @@ class fakesock(object):
             self._closed = True
 
         def makefile(self, mode='r', bufsize=-1):
-            """Returns this fake socket's own StringIO buffer.
+            """Returns this fake socket's own tempfile buffer.
 
             If there is an entry associated with the socket, the file
             descriptor gets filled in with the entry data before being
@@ -358,7 +371,7 @@ class fakesock(object):
             when HTTPretty identifies that someone is trying to send
             non-http data.
 
-            The received bytes are written in this socket's StringIO
+            The received bytes are written in this socket's tempfile
             buffer so that HTTPretty can return it accordingly when
             necessary.
             """

tests/unit/test_core.py

@@ -322,7 +322,7 @@ def test_fakesock_socket_real_sendall(old_socket):
     real_socket.recv.called.should.be.false
 
     # And the buffer is empty
-    socket.fd.getvalue().should.equal(b'')
+    socket.fd.read().should.equal(b'')
 
     # And connect was never called
     real_socket.connect.called.should.be.false
@@ -356,7 +356,7 @@ def test_fakesock_socket_real_sendall_when_http(old_socket):
     ])
 
     # And the buffer should contain the data from the server
-    socket.fd.getvalue().should.equal(b"response from server")
+    socket.fd.read().should.equal(b"response from server")
 
     # And connect was called
     real_socket.connect.called.should.be.true
@@ -391,7 +391,7 @@ def test_fakesock_socket_real_sendall_continue_eagain_when_http(socket, old_sock
     ])
 
     # And the buffer should contain the data from the server
-    socket.fd.getvalue().should.equal(b"after error")
+    socket.fd.read().should.equal(b"after error")
 
     # And connect was called
     real_socket.connect.called.should.be.true
@@ -424,7 +424,7 @@ def test_fakesock_socket_real_sendall_socket_error_when_http(socket, old_socket)
     real_socket.recv.assert_called_once_with(socket._bufsize)
 
     # And the buffer should contain the data from the server
-    socket.fd.getvalue().should.equal(b"")
+    socket.fd.read().should.equal(b"")
 
     # And connect was called
     real_socket.connect.called.should.be.true
@@ -464,7 +464,7 @@ def test_fakesock_socket_real_sendall_when_http(POTENTIAL_HTTP_PORTS, old_socket
     ])
 
     # And the buffer should contain the data from the server
-    socket.fd.getvalue().should.equal(b"response from foobar :)")
+    socket.fd.read().should.equal(b"response from foobar :)")
 
 
 @patch('httpretty.core.old_socket')

tests/unit/test_httpretty.py

@@ -272,7 +272,7 @@ def test_Entry_class_counts_multibyte_characters_in_bytes():
     entry = Entry(HTTPretty.GET, 'http://example.com', 'こんにちは')
     buf = FakeSockFile()
     entry.fill_filekind(buf)
-    response = buf.getvalue()
+    response = buf.read()
     expect(b'content-length: 15\n').to.be.within(response)