* It's now possible to configure ``test_run_concurrency`` in ``.testr.conf``

  to have concurrency defined by a callout. (Robert Collins)

3 files changed, 62 insertions, 4 deletions

diff --git a/NEWS b/NEWS
index 74f56e6..7c1bf86 100644
--- a/NEWS
+++ b/NEWS
@@ -5,6 +5,12 @@ testrepository release notes
 NEXT (In development)
 +++++++++++++++++++++
 
+IMPROVEMENTS
+------------
+
+* It's now possible to configure ``test_run_concurrency`` in ``.testr.conf``
+  to have concurrency defined by a callout. (Robert Collins)
+
 0.0.9
 +++++
 
diff --git a/testrepository/testcommand.py b/testrepository/testcommand.py
index 84fcf4c..eb06302 100644
--- a/testrepository/testcommand.py
+++ b/testrepository/testcommand.py
@@ -147,6 +147,8 @@ class TestListingFixture(Fixture):
         else:
             self.concurrency = self.ui.options.concurrency
             if not self.concurrency:
+                self.concurrency = self.callout_concurrency()
+            if not self.concurrency:
                 self.concurrency = self.local_concurrency()
             if not self.concurrency:
                 self.concurrency = 1
@@ -286,6 +288,22 @@ class TestListingFixture(Fixture):
             partition.append(test_id)
         return partitions
 
+    def callout_concurrency(self):
+        """Callout for user defined concurrency."""
+        try:
+            concurrency_cmd = self._parser.get(
+                'DEFAULT', 'test_run_concurrency', None)
+        except ConfigParser.NoOptionError:
+            return None
+        run_proc = self.ui.subprocess_Popen(concurrency_cmd, shell=True,
+            stdout=subprocess.PIPE, stdin=subprocess.PIPE)
+        out, err = run_proc.communicate()
+        if run_proc.returncode:
+            raise ValueError(
+                "test_run_concurrency failed: exit code %d, stderr=%r" % (
+                run_proc.returncode, err))
+        return int(out.strip())
+
     def local_concurrency(self):
         if sys.platform == 'linux2':
             concurrency = None
diff --git a/testrepository/tests/test_testcommand.py b/testrepository/tests/test_testcommand.py
index 2b66997..ecdc012 100644
--- a/testrepository/tests/test_testcommand.py
+++ b/testrepository/tests/test_testcommand.py
@@ -18,7 +18,7 @@ import os.path
 import optparse
 import re
 
-from testtools.matchers import MatchesException, Raises
+from testtools.matchers import MatchesException, raises
 from testtools.testresult.doubles import ExtendedTestResult
 
 from testrepository.commands import run
@@ -78,14 +78,14 @@ class TestTestCommand(ResourcedTestCase):
     def test_get_run_command_no_config_file_errors(self):
         ui, command = self.get_test_ui_and_cmd()
         self.assertThat(command.get_run_command,
-            Raises(MatchesException(ValueError('No .testr.conf config file'))))
+            raises(ValueError('No .testr.conf config file')))
 
     def test_get_run_command_no_config_settings_errors(self):
         ui, command = self.get_test_ui_and_cmd()
         self.set_config('')
         self.assertThat(command.get_run_command,
-            Raises(MatchesException(ValueError(
-            'No test_command option present in .testr.conf'))))
+            raises(ValueError(
+            'No test_command option present in .testr.conf')))
 
     def test_get_run_command_returns_fixture_makes_IDFILE(self):
         ui, command = self.get_test_ui_and_cmd()
@@ -244,6 +244,40 @@ class TestTestCommand(ResourcedTestCase):
         self.set_config('[DEFAULT]\nfilter_tags=foo bar\n')
         self.assertEqual(set(['foo', 'bar']), command.get_filter_tags())
 
+    def test_callout_concurrency(self):
+        ui, command = self.get_test_ui_and_cmd()
+        ui.proc_outputs = ['4']
+        self.set_config(
+            '[DEFAULT]\ntest_run_concurrency=probe\n'
+            'test_command=foo\n')
+        fixture = self.useFixture(command.get_run_command())
+        self.assertEqual(4, fixture.callout_concurrency())
+        self.assertEqual([
+            ('popen', ('probe',), {'shell': True, 'stdin': -1, 'stdout': -1}),
+            ('communicate',)], ui.outputs)
+
+    def test_callout_concurrency_failed(self):
+        ui, command = self.get_test_ui_and_cmd()
+        ui.proc_results = [1]
+        self.set_config(
+            '[DEFAULT]\ntest_run_concurrency=probe\n'
+            'test_command=foo\n')
+        fixture = self.useFixture(command.get_run_command())
+        self.assertThat(lambda:fixture.callout_concurrency(), raises(
+            ValueError("test_run_concurrency failed: exit code 1, stderr=''")))
+        self.assertEqual([
+            ('popen', ('probe',), {'shell': True, 'stdin': -1, 'stdout': -1}),
+            ('communicate',)], ui.outputs)
+
+    def test_callout_concurrency_not_set(self):
+        ui, command = self.get_test_ui_and_cmd()
+        self.set_config(
+            '[DEFAULT]\n'
+            'test_command=foo\n')
+        fixture = self.useFixture(command.get_run_command())
+        self.assertEqual(None, fixture.callout_concurrency())
+        self.assertEqual([], ui.outputs)
+
     def test_make_result(self):
         # Just a simple 'the dots are joined' test. More later.
         ui, command = self.get_test_ui_and_cmd()