ModelTester for recursive tree models

[phil65]

I´m running into a recursive loop when using the ModelTester with recursive tree models. QAbstractItemModelTester gained an option to not call fetchMore with Qt6.4. ( https://doc.qt.io/qt-6/qabstractitemmodeltester.html#setUseFetchMore ) Since the _qt_tester attribute of ModelTester is only set after calling ModelTester.check(), there is no way to use that option. Would be nice if that option could get added. Thank you!

[The-Compiler]

Makes sense to support that option (and backport the logic to our Python reimplementation), yep!

Relevant change: Use QAbstractItemModelTester or QFileSystemModel (Ie5d2e22f) · Gerrit Code Review

No other relevant changes in Qt so far:

df9d882d41 Port from container.count()/length() to size()
76b07b05f0 Doc: add missing "see also"
2f35653a30 Use QAbstractItemModelTester or QFileSystemModel
05fc3aef53 Use SPDX license identifiers
b6759ff81c QAbstractItemModelTester: Fix typos in debug output    # <- Python reimplementation is here

[The-Compiler]

I did some initial work on this:

```diff diff --git i/src/pytestqt/modeltest.py w/src/pytestqt/modeltest.py index b2df3fe..c3d0340 100644 --- i/src/pytestqt/modeltest.py +++ w/src/pytestqt/modeltest.py @@ -71,6 +71,7 @@ class ModelTester: def __init__(self, config): self._model = None self._fetching_more = None + self._use_fetch_more = True self._insert = None self._remove = None self._changing = [] @@ -95,7 +96,7 @@ def _modelindex_debug(self, index): id(index), ) - def check(self, model, force_py=False): + def check(self, model, force_py=False, use_fetch_more=True): """Runs a series of checks in the given model. Connect to all of the models signals. @@ -106,6 +107,9 @@ def check(self, model, force_py=False): :param force_py: Force using the Python implementation, even if the C++ implementation is available. + :param use_fetch_more: + Set to ``False`` to disable using ``fetchMore()`` on the model. If + using the Qt implementation, this needs Qt 6.4 or newer. """ assert model is not None @@ -116,6 +120,10 @@ def check(self, model, force_py=False): self._qt_tester = qt_api.QtTest.QAbstractItemModelTester( model, reporting_mode ) + if not use_fetch_more: + # If using use_fetch_more=False with Qt < 6.4, this will raise + # an AttributeError, which we let propagate. + self._qt_tester.setUseFetchMore(False) self._debug("Using Qt C++ tester") return @@ -123,6 +131,7 @@ def check(self, model, force_py=False): self._model = model self._fetching_more = False + self._use_fetch_more = use_fetch_more self._insert = [] self._remove = [] self._changing = [] @@ -943,6 +952,8 @@ def _has_children(self, parent=qt_api.QtCore.QModelIndex()): def _fetch_more(self, parent): """Call ``fetchMore`` on the model and set ``self._fetching_more``.""" + if not self._use_fetch_more: + return self._fetching_more = True self._model.fetchMore(parent) self._fetching_more = False diff --git i/tests/test_modeltest.py w/tests/test_modeltest.py index 665f125..c32f8de 100644 --- i/tests/test_modeltest.py +++ w/tests/test_modeltest.py @@ -302,21 +302,41 @@ def rowCount(self, parent=None): assert model.row_count_did_run -def test_fetch_more(qtmodeltester): - class Model(qt_api.QtGui.QStandardItemModel): - def canFetchMore(self, parent): - return True +class FetchMoreModel(qt_api.QtGui.QStandardItemModel): - def fetchMore(self, parent): - """Force a re-check while fetching more.""" - self.setData(self.index(0, 0), "bar") + def __init__(self, fetch_more_allowed=True, parent=None): + super().__init__(parent) + self._fetch_more_allowed = fetch_more_allowed - model = Model() + def canFetchMore(self, parent): + return True + + def fetchMore(self, parent): + """Force a re-check while fetching more.""" + assert self._fetch_more_allowed + self.setData(self.index(0, 0), "bar") + + +def test_fetch_more(qtmodeltester): + model = FetchMoreModel() item = qt_api.QtGui.QStandardItem("foo") model.setItem(0, 0, item) qtmodeltester.check(model, force_py=True) +@pytest.mark.parametrize("force_py", [True, False]) +def test_fetch_more_disabled(qtmodeltester, force_py): + model = FetchMoreModel(fetch_more_allowed=False) + item = qt_api.QtGui.QStandardItem("foo") + model.setItem(0, 0, item) + try: + # Will raise in the model if fetchMore is called + qtmodeltester.check(model, force_py=force_py, use_fetch_more=False) + except AttributeError as e: + # Qt tester on Qt < 6.4 + pytest.skip(str(e)) + + def test_invalid_parent(qtmodeltester): class Model(qt_api.QtGui.QStandardItemModel): def parent(self, index): ```

but the tests fail:

====================================================== FAILURES ======================================================
__________________________________________ test_fetch_more_disabled[False] ___________________________________________
CALL ERROR: Exceptions caught in Qt event loop:
________________________________________________________________________________
Traceback (most recent call last):
  File "/home/florian/proj/pytest-qt/tests/test_modeltest.py", line 316, in fetchMore
    assert self._fetch_more_allowed
AssertionError: assert False
 +  where False = <test_modeltest.FetchMoreModel object at 0x7f867950e7a0>._fetch_more_allowed
________________________________________________________________________________
Traceback (most recent call last):
  File "/home/florian/proj/pytest-qt/tests/test_modeltest.py", line 316, in fetchMore
    assert self._fetch_more_allowed
AssertionError: assert False
 +  where False = <test_modeltest.FetchMoreModel object at 0x7f867950e7a0>._fetch_more_allowed
________________________________________________________________________________
------------------------------------------------ Captured stdout call ------------------------------------------------
modeltest: Using Qt C++ tester

and I believe this is Qt's fault:

• Given that useFetchMore is only a property, it follows that it needs to be set after creating the model tester and passing a model to it
• However, passing a model to it immediately runs all tests, which calls nonDestructiveBasicTest
• That in turn already calls fetchMore(), before we even had a chance to disable that

Not sure if I should report this as a Qt bug, or just adjust the test so it allows fetchMore to be called exactly once...

[phil65]

Did you try setting the property in the constructor? QAbstractItemModelTester(model, useFetchMore=False)

(With Qt for Python, all properties can be set via constructor)

[The-Compiler]

That's just syntactic sugar for:

tester = QAbstractItemModelTester(model)
tester.setUseFetchMore(False)

so it shows the same problem as well.

[phil65]

Okay. Thanks for trying!