test_multiChannelLaserSource.py

''' Make a Configurable subclass called MessagePasser

    The MessagePasser acting as a driver writes to a buffer,
    instead of a pyvisa.mbSession.

    The buffer is read by another MessagePasser (acting as the instrument)

    This is not really an intended use for message passing between objects in code,
    but hey it shows that Configurable does a good job emulating how a real-life
    configurable instrument works.
'''
import pytest
from lightlab.equipment.abstract_drivers import Configurable, AbstractDriver
from lightlab.equipment.lab_instruments import ILX_7900B_LS
from lightlab.util.io import ChannelError


class LS_MessageSender(ILX_7900B_LS):
    writeBuffer = None
    sleepOn = dict(OUT=0, WAVE=0, LEVEL=0)

    def __init__(self, **kwargs):
        self.writeBuffer = []
        super().__init__(**kwargs)

    def open(self): pass

    def write(self, string):
        self.writeBuffer.append(string)
        print(string)

    def query(self, string):
        ''' Argument "string" is ignored '''
        return '1550'

    @property
    def wlRanges(self):
        return [(1545, 1555)] * len(self.useChans)


def test_laser():
    LS = LS_MessageSender(name='foo', address='NULL', useChans=[0, 2, 1], directInit=True)
    assert LS.writeBuffer == []

    # Channel mischief
    with pytest.raises(ChannelError):
        LS.setChannelEnable({3: 1})
    with pytest.raises(ChannelError):
        LS.enableState = [0]
    with pytest.raises(ChannelError):
        LS.enableState = [0, 0, 0, 0]

    # Writes only if values changed
    LS.wls
    sentLen = len(LS.writeBuffer)
    LS.wls = [1549, 1550, 1550]  # It already thinks that ch 1, 2 are 1550
    assert len(LS.writeBuffer) == sentLen + 2
    LS.wls = [1549, 1550, 1550]
    assert len(LS.writeBuffer) == sentLen + 2