tests: initial first_stage_test.

tests/first_stage_test.py

+
+import subprocess
+import unittest
+
+import mitogen.master
+import testlib
+
+
+class CommandLineTest(testlib.RouterMixin, testlib.TestCase):
+    # Ensure this version of Python produces a command line that is sufficient
+    # to bootstrap this version of Python.
+    #
+    # TODO:
+    #   * 2.7 starting 2.4
+    #   * 2.7 starting 3.x
+    #   * 3.x starting 2.7
+
+    def test_valid_syntax(self):
+        stream = mitogen.master.Stream(self.router, 0)
+        args = stream.get_boot_command()
+
+        # Executing the boot command will print "EC0" and expect to read from
+        # stdin, which will fail because it's pointing at /dev/null, causing
+        # the forked child to crash with an EOFError and disconnect its write
+        # pipe. The forked and freshly execed parent will get a 0-byte read
+        # from the pipe, which is a valid script, and therefore exit indicating
+        # success.
+
+        fp = file("/dev/null", "r")
+        proc = subprocess.Popen(args,
+            stdin=fp,
+            stdout=subprocess.PIPE,
+            stderr=subprocess.PIPE,
+        )
+        stdout, stderr = proc.communicate()
+        self.assertEquals(0, proc.returncode)
+        self.assertEquals("EC0\n", stdout)
+        self.assertContains("EOFError", stderr)
+
+
+if __name__ == '__main__':
+    unittest.main()

tests/testlib.py

@@ -111,6 +111,9 @@ class TestCase(unittest.TestCase):
             assert 0, '%r raised %r, not %r' % (func, e, exc)
         assert 0, '%r did not raise %r' % (func, exc)
 
+    def assertContains(self, needle, hay):
+        assert needle in hay, "%r not found in %r" % (needle, hay)
+
 
 class DockerizedSshDaemon(object):
     def __init__(self):