pyserial/examples/test.py

#! /usr/bin/env python
# Python Serial Port Extension for Win32, Linux, BSD, Jython
# see __init__.py
#
# (C) 2001-2008 Chris Liechti <cliechti@gmx.net>
# this is distributed under a free software license, see license.txt

"""\
Some tests for the serial module.
Part of pyserial (http://pyserial.sf.net)  (C)2001-2008 cliechti@gmx.net

Intended to be run on different platforms, to ensure portability of
the code.

For all these tests a simple hardware is required.
Loopback HW adapter:
Shortcut these pin pairs:
 TX  <-> RX
 RTS <-> CTS
 DTR <-> DSR

On a 9 pole DSUB these are the pins (2-3) (4-6) (7-8)
"""

import unittest, threading, time
import serial

#on which port should the tests be performed:
PORT=0


class Test4_Nonblocking(unittest.TestCase):
    """Test with timeouts"""
    timeout=0
    def setUp(self):
        self.s = serial.Serial(PORT,timeout=self.timeout)
    def tearDown(self):
        self.s.close()

    def test0_Messy(self):
        """NonBlocking (timeout=0)"""
        #this is only here to write out the message in verbose mode
        #because Test3 and Test4 print the same messages

    def test1_ReadEmpty(self):
        """timeout: After port open, the input buffer must be empty"""
        self.failUnless(self.s.read(1)=='', "expected empty buffer")
    def test2_Loopback(self):
        """timeout: each sent character should return (binary test).
           this is also a test for the binary capability of a port."""
        for c in map(chr,range(256)):
            self.s.write(c)
            time.sleep(0.02)    #there might be a small delay until the character is ready (especialy on win32)
            self.failUnless(self.s.inWaiting()==1, "expected exactly one character for inWainting()")
            self.failUnless(self.s.read(1)==c, "expected a '%s' which was written before" % c)
        self.failUnless(self.s.read(1)=='', "expected empty buffer after all sent chars are read")
    def test2_LoopbackTimeout(self):
        """timeout: test the timeout/immediate return.
        partial results should be returned."""
        self.s.write("HELLO")
        time.sleep(0.1)    #there might be a small delay until the character is ready (especialy on win32)
        #read more characters as are available to run in the timeout
        self.failUnless(self.s.read(10)=='HELLO', "expected the 'HELLO' which was written before")
        self.failUnless(self.s.read(1)=='', "expected empty buffer after all sent chars are read")


class Test3_Timeout(Test4_Nonblocking):
    """Same tests as the NonBlocking ones but this time with timeout"""
    timeout=1
    def test0_Messy(self):
        """Blocking (timeout=1)"""
        #this is only here to write out the message in verbose mode
        #because Test3 and Test4 print the same messages

class SendEvent(threading.Thread):
    def __init__(self, serial, delay=1):
        threading.Thread.__init__(self)
        self.serial = serial
        self.delay = delay
        self.x = threading.Event()
        self.stopped = 0
        self.start()
    def run(self):
        time.sleep(self.delay)
        if not self.stopped:
            self.serial.write("E")
        self.x.set()
    def isSet(self):
        return self.x.isSet()
    def stop(self):
        self.stopped = 1
        self.x.wait()

class Test1_Forever(unittest.TestCase):
    """Tests a port with no timeout. These tests require that a
    character is sent after some time to stop the test, this is done
    through the SendEvent class and the Loopback HW."""
    def setUp(self):
        self.s = serial.Serial(PORT, timeout=None)
        self.event = SendEvent(self.s)
    def tearDown(self):
        self.event.stop()
        self.s.close()

    def test2_ReadEmpty(self):
        """no timeout: after port open, the input buffer must be empty (read).
        a character is sent after some time to terminate the test (SendEvent)."""
        c = self.s.read(1)
        if not (self.event.isSet() and c == 'E'):
            self.fail("expected marker")

class Test2_Forever(unittest.TestCase):
    """Tests a port with no timeout"""
    def setUp(self):
        self.s = serial.Serial(PORT,timeout=None)
    def tearDown(self):
        self.s.close()

    def test1_inWaitingEmpty(self):
        """no timeout: after port open, the input buffer must be empty (inWaiting)"""
        self.failUnless(self.s.inWaiting()==0, "expected empty buffer")

    def test2_Loopback(self):
        """no timeout: each sent character should return (binary test).
           this is also a test for the binary capability of a port."""
        for c in map(chr,range(256)):
            self.s.write(c)
            time.sleep(0.02)    #there might be a small delay until the character is ready (especialy on win32)
            self.failUnless(self.s.inWaiting()==1, "expected exactly one character for inWainting()")
            self.failUnless(self.s.read(1)==c, "expected an '%s' which was written before" % c)
        self.failUnless(self.s.inWaiting()==0, "expected empty buffer after all sent chars are read")


class Test0_DataWires(unittest.TestCase):
    """Test modem control lines"""
    def setUp(self):
        self.s = serial.Serial(PORT)
    def tearDown(self):
        self.s.close()

    def test1_RTS(self):
        """Test RTS/CTS"""
        self.s.setRTS(0)
        self.failUnless(not self.s.getCTS(), "CTS -> 0")
        self.s.setRTS(1)
        self.failUnless(self.s.getCTS(), "CTS -> 1")

    def test2_DTR(self):
        """Test DTR/DSR"""
        self.s.setDTR(0)
        self.failUnless(not self.s.getDSR(), "DSR -> 0")
        self.s.setDTR(1)
        self.failUnless(self.s.getDSR(), "DSR -> 1")

    def test3_RI(self):
        """Test RI"""
        self.failUnless(not self.s.getRI(), "RI -> 0")

class Test_MoreTimeouts(unittest.TestCase):
    """Test with timeouts"""
    def setUp(self):
        self.s = serial.Serial()        #create an closed serial port
    
    def tearDown(self):
        self.s.close()

    def test_WriteTimeout(self):
        """Test write() timeout."""
        #use xonxoff setting and the loopback adapter to switch traffic on hold
        self.s.port = PORT
        self.s.writeTimeout = 1
        self.s.xonxoff = 1
        self.s.open()
        self.s.write(serial.XOFF)
        time.sleep(0.1) #some systems need a little delay so that they can react on XOFF
        t1 = time.time()
        self.failUnlessRaises(serial.SerialTimeoutException, self.s.write, "timeout please"*100)
        t2 = time.time()
        self.failUnless( 1 <= (t2-t1) < 2, "Timeout not in the given intervall (%s)" % (t2-t1))

if __name__ == '__main__':
    import sys
    print __doc__
    if len(sys.argv) > 1:
        PORT = sys.argv[1]
    print "Testing port", PORT
    sys.argv[1:] = ['-v']
    # When this module is executed from the command-line, it runs all its tests
    unittest.main()