Patch #1675471: convert test_pty to unittest.

Lib/test/output/test_pty

-test_pty
-I wish to buy a fish license.
-For my pet fish, Eric.

Lib/test/test_pty.py

-import pty, os, sys, signal
-from test.test_support import verbose, TestFailed, TestSkipped
+import pty
+import os
+import signal
+from test.test_support import verbose, TestSkipped, run_unittest
+import unittest
 
 TEST_STRING_1 = "I wish to buy a fish license.\n"
 TEST_STRING_2 = "For my pet fish, Eric.\n"
@@ -11,6 +14,7 @@ else:
     def debug(msg):
         pass
 
+
 def normalize_output(data):
     # Some operating systems do conversions on newline.  We could possibly
     # fix that by doing the appropriate termios.tcsetattr()s.  I couldn't
@@ -32,58 +36,59 @@ def normalize_output(data):
 
     return data
 
+
 # Marginal testing of pty suite. Cannot do extensive 'do or fail' testing
 # because pty code is not too portable.
+class PtyTest(unittest.TestCase):
+    def setUp(self):
+        # isatty() and close() can hang on some platforms.  Set an alarm 
+        # before running the test to make sure we don't hang forever.
+        self.old_alarm = signal.signal(signal.SIGALRM, self.handle_sig)
+        signal.alarm(10)
+    
+    def tearDown(self):
+        # remove alarm, restore old alarm handler
+        signal.alarm(0)
+        signal.signal(signal.SIGALRM, self.old_alarm)
     
-def test_basic_pty():
+    def handle_sig(self, sig, frame):
+        self.fail("isatty hung")
+    
+    def test_basic(self):
         try:
             debug("Calling master_open()")
             master_fd, slave_name = pty.master_open()
-        debug("Got master_fd '%d', slave_name '%s'"%(master_fd, slave_name))
-        debug("Calling slave_open(%r)"%(slave_name,))
+            debug("Got master_fd '%d', slave_name '%s'" %
+                  (master_fd, slave_name))
+            debug("Calling slave_open(%r)" % (slave_name,))
             slave_fd = pty.slave_open(slave_name)
-        debug("Got slave_fd '%d'"%slave_fd)
+            debug("Got slave_fd '%d'" % slave_fd)
         except OSError:
             # " An optional feature could not be imported " ... ?
             raise TestSkipped, "Pseudo-terminals (seemingly) not functional."
 
-    if not os.isatty(slave_fd):
-        raise TestFailed, "slave_fd is not a tty"
+        self.assertTrue(os.isatty(slave_fd), 'slave_fd is not a tty')
     
         debug("Writing to slave_fd")
         os.write(slave_fd, TEST_STRING_1)
         s1 = os.read(master_fd, 1024)
-    sys.stdout.write(normalize_output(s1))
+        self.assertEquals('I wish to buy a fish license.\n', 
+                          normalize_output(s1))
     
         debug("Writing chunked output")
         os.write(slave_fd, TEST_STRING_2[:5])
         os.write(slave_fd, TEST_STRING_2[5:])
         s2 = os.read(master_fd, 1024)
-    sys.stdout.write(normalize_output(s2))
+        self.assertEquals('For my pet fish, Eric.\n', normalize_output(s2))
     
         os.close(slave_fd)
         os.close(master_fd)
 
-def handle_sig(sig, frame):
-    raise TestFailed, "isatty hung"
-
-# isatty() and close() can hang on some platforms
-# set an alarm before running the test to make sure we don't hang forever
-old_alarm = signal.signal(signal.SIGALRM, handle_sig)
-signal.alarm(10)
-
-try:
-    test_basic_pty()
-finally:
-    # remove alarm, restore old alarm handler
-    signal.alarm(0)
-    signal.signal(signal.SIGALRM, old_alarm)
 
-# basic pty passed.
-
-debug("calling pty.fork()")
-pid, master_fd = pty.fork()
-if pid == pty.CHILD:
+    def test_fork(self):
+        debug("calling pty.fork()")
+        pid, master_fd = pty.fork()
+        if pid == pty.CHILD:
             # stdout should be connected to a tty.
             if not os.isatty(1):
                 debug("Child's fd 1 is not a tty?!")
@@ -99,8 +104,8 @@ if pid == pty.CHILD:
                 debug("Good: OSError was raised.")
                 pass
             except AttributeError:
-        # Have pty, but not setsid() ?
-        debug("No setsid() available ?")
+                # Have pty, but not setsid()?
+                debug("No setsid() available?")
                 pass
             except:
                 # We don't want this error to propagate, escaping the call to
@@ -113,8 +118,8 @@ if pid == pty.CHILD:
                 debug("os.setsid() succeeded! (bad!)")
                 os._exit(2)
             os._exit(4)
-else:
-    debug("Waiting for child (%d) to finish."%pid)
+        else:
+            debug("Waiting for child (%d) to finish." % pid)
             ##line = os.read(master_fd, 80)
             ##lines = line.replace('\r\n', '\n').split('\n')
             ##if False and lines != ['In child, calling os.setsid()',
@@ -123,15 +128,15 @@ else:
         
             (pid, status) = os.waitpid(pid, 0)
             res = status >> 8
-    debug("Child (%d) exited with status %d (%d)."%(pid, res, status))
+            debug("Child (%d) exited with status %d (%d)." % (pid, res, status))
             if res == 1:
-        raise TestFailed, "Child raised an unexpected exception in os.setsid()"
+                self.fail("Child raised an unexpected exception in os.setsid()")
             elif res == 2:
-        raise TestFailed, "pty.fork() failed to make child a session leader."
+                self.fail("pty.fork() failed to make child a session leader.")
             elif res == 3:
-        raise TestFailed, "Child spawned by pty.fork() did not have a tty as stdout"
+                self.fail("Child spawned by pty.fork() did not have a tty as stdout")
             elif res != 4:
-        raise TestFailed, "pty.fork() failed for unknown reasons."
+                self.fail("pty.fork() failed for unknown reasons.")
         
             ##debug("Reading from master_fd now that the child has exited")
             ##try:
@@ -141,7 +146,12 @@ else:
             ##else:
             ##    raise TestFailed("Read from master_fd did not raise exception")
         
+        os.close(master_fd)
+        
+        # pty.fork() passed.
 
-os.close(master_fd)
+def test_main(verbose=None):
+    run_unittest(PtyTest)
 
-# pty.fork() passed.
+if __name__ == "__main__":
+    test_main()