pyqtgraph/tests/graphicsItems/test_GraphicsItem.py

import weakref
import pyqtgraph as pg
import faulthandler
faulthandler.enable()

pg.mkQApp()

def test_getViewWidget():
    view = pg.PlotWidget()
    vref = weakref.ref(view)
    item = pg.InfiniteLine()
    view.addItem(item)
    assert item.getViewWidget() is view
    del view
    assert vref() is None
    assert item.getViewWidget() is None

def test_getViewWidget_deleted():
    view = pg.PlotWidget()
    item = pg.InfiniteLine()
    view.addItem(item)
    assert item.getViewWidget() is view
    
    # Arrange to have Qt automatically delete the view widget
    obj = pg.QtGui.QWidget()
    view.setParent(obj)
    del obj

    assert not pg.Qt.isQObjectAlive(view)
    assert item.getViewWidget() is None