Extract extract_result

testtools/_deferred.py

@@ -0,0 +1,30 @@
+# Copyright (c) testtools developers. See LICENSE for details.
+
+"""Utilities for Deferreds."""
+
+
+class DeferredNotFired(Exception):
+    """Raised when we extract a result from a Deferred that's not fired yet."""
+
+
+def extract_result(deferred):
+    """Extract the result from a fired deferred.
+
+    It can happen that you have an API that returns Deferreds for
+    compatibility with Twisted code, but is in fact synchronous, i.e. the
+    Deferreds it returns have always fired by the time it returns.  In this
+    case, you can use this function to convert the result back into the usual
+    form for a synchronous API, i.e. the result itself or a raised exception.
+
+    It would be very bad form to use this as some way of checking if a
+    Deferred has fired.
+    """
+    failures = []
+    successes = []
+    deferred.addCallbacks(successes.append, failures.append)
+    if len(failures) == 1:
+        failures[0].raiseException()
+    elif len(successes) == 1:
+        return successes[0]
+    else:
+        raise DeferredNotFired("%r has not fired yet." % (deferred,))

testtools/_spinner.py

@@ -7,8 +7,6 @@ you couldn't write this yourself, you should not be using it.
 """
 
 __all__ = [
-    'DeferredNotFired',
-    'extract_result',
     'NoResultError',
     'not_reentrant',
     'ReentryError',
@@ -54,33 +52,6 @@ def not_reentrant(function, _calls={}):
     return mergeFunctionMetadata(function, decorated)
 
 
-class DeferredNotFired(Exception):
-    """Raised when we extract a result from a Deferred that's not fired yet."""
-
-
-def extract_result(deferred):
-    """Extract the result from a fired deferred.
-
-    It can happen that you have an API that returns Deferreds for
-    compatibility with Twisted code, but is in fact synchronous, i.e. the
-    Deferreds it returns have always fired by the time it returns.  In this
-    case, you can use this function to convert the result back into the usual
-    form for a synchronous API, i.e. the result itself or a raised exception.
-
-    It would be very bad form to use this as some way of checking if a
-    Deferred has fired.
-    """
-    failures = []
-    successes = []
-    deferred.addCallbacks(successes.append, failures.append)
-    if len(failures) == 1:
-        failures[0].raiseException()
-    elif len(successes) == 1:
-        return successes[0]
-    else:
-        raise DeferredNotFired("%r has not fired yet." % (deferred,))
-
-
 def trap_unhandled_errors(function, *args, **kwargs):
     """Run a function, trapping any unhandled errors in Deferreds.
 

testtools/deferredruntest.py

@@ -31,8 +31,8 @@ import sys
 from testtools.compat import StringIO
 from testtools.content import text_content
 from testtools.runtest import RunTest
+from testtools._deferred import extract_result
 from testtools._spinner import (
-    extract_result,
     NoResultError,
     Spinner,
     TimeoutError,

testtools/tests/__init__.py

@@ -14,6 +14,7 @@ def test_suite():
         test_compat,
         test_content,
         test_content_type,
+        test_deferred,
         test_deferredmatchers,
         test_deferredruntest,
         test_distutilscmd,
@@ -35,6 +36,7 @@ def test_suite():
         test_compat,
         test_content,
         test_content_type,
+        test_deferred,
         test_deferredmatchers,
         test_deferredruntest,
         test_distutilscmd,

testtools/tests/test_deferred.py

@@ -0,0 +1,51 @@
+# Copyright (c) testtools developers. See LICENSE for details.
+
+"""Tests for testtools._deferred."""
+
+from extras import try_import
+
+from testtools.matchers import (
+    Equals,
+    MatchesException,
+    Raises,
+    )
+from testtools.tests.test_spinner import NeedsTwistedTestCase
+
+from testtools._deferred import DeferredNotFired, extract_result
+
+defer = try_import('twisted.internet.defer')
+Failure = try_import('twisted.python.failure.Failure')
+
+
+class TestExtractResult(NeedsTwistedTestCase):
+
+    def test_not_fired(self):
+        # _spinner.extract_result raises _spinner.DeferredNotFired if it's
+        # given a Deferred that has not fired.
+        self.assertThat(
+            lambda: extract_result(defer.Deferred()),
+            Raises(MatchesException(DeferredNotFired)))
+
+    def test_success(self):
+        # _spinner.extract_result returns the value of the Deferred if it has
+        # fired successfully.
+        marker = object()
+        d = defer.succeed(marker)
+        self.assertThat(extract_result(d), Equals(marker))
+
+    def test_failure(self):
+        # _spinner.extract_result raises the failure's exception if it's given
+        # a Deferred that is failing.
+        try:
+            1/0
+        except ZeroDivisionError:
+            f = Failure()
+        d = defer.fail(f)
+        self.assertThat(
+            lambda: extract_result(d),
+            Raises(MatchesException(ZeroDivisionError)))
+
+
+def test_suite():
+    from unittest2 import TestLoader, TestSuite
+    return TestLoader().loadTestsFromName(__name__)

testtools/tests/test_spinner.py

@@ -63,33 +63,6 @@ class TestNotReentrant(NeedsTwistedTestCase):
         self.assertEqual(2, len(calls))
 
 
-class TestExtractResult(NeedsTwistedTestCase):
-
-    def test_not_fired(self):
-        # _spinner.extract_result raises _spinner.DeferredNotFired if it's
-        # given a Deferred that has not fired.
-        self.assertThat(lambda:_spinner.extract_result(defer.Deferred()),
-            Raises(MatchesException(_spinner.DeferredNotFired)))
-
-    def test_success(self):
-        # _spinner.extract_result returns the value of the Deferred if it has
-        # fired successfully.
-        marker = object()
-        d = defer.succeed(marker)
-        self.assertThat(_spinner.extract_result(d), Equals(marker))
-
-    def test_failure(self):
-        # _spinner.extract_result raises the failure's exception if it's given
-        # a Deferred that is failing.
-        try:
-            1/0
-        except ZeroDivisionError:
-            f = Failure()
-        d = defer.fail(f)
-        self.assertThat(lambda:_spinner.extract_result(d),
-            Raises(MatchesException(ZeroDivisionError)))
-
-
 class TestTrapUnhandledErrors(NeedsTwistedTestCase):
 
     def test_no_deferreds(self):