Fix RawArray init kwargs retaining stale data

doc/changes/dev/14075.bugfix.rst

@@ -0,0 +1 @@
+Fix :class:`mne.io.RawArray` constructor metadata retaining stale array data after operations replace the active data, by :newcontrib:`Floze`.

mne/io/array/_array.py

@@ -50,6 +50,29 @@ class RawArray(BaseRaw):
     * AU: misc
     """
 
+    _extra_attributes = ("_init_kwargs_without_data",)
+
+    @property
+    def _init_kwargs(self):
+        """Return constructor arguments without retaining stale data."""
+        try:
+            kwargs = self._init_kwargs_without_data
+        except AttributeError:
+            # Support instances serialized before ``data`` was stored dynamically.
+            kwargs = self.__dict__.pop("_init_kwargs")
+            self._init_kwargs = kwargs
+            kwargs = self._init_kwargs_without_data
+        if kwargs is None:
+            return None
+        return dict(data=self._data, **kwargs)
+
+    @_init_kwargs.setter
+    def _init_kwargs(self, kwargs):
+        if kwargs is not None:
+            kwargs = kwargs.copy()
+            kwargs.pop("data", None)
+        self._init_kwargs_without_data = kwargs
+
     @verbose
     def __init__(self, data, info, first_samp=0, copy="auto", verbose=None):
         _validate_type(info, "info", "info")

mne/io/array/tests/test_array.py

@@ -2,6 +2,9 @@
 # License: BSD-3-Clause
 # Copyright the MNE-Python contributors.
 
+import gc
+import pickle
+import weakref
 from pathlib import Path
 
 import matplotlib.pyplot as plt
@@ -74,6 +77,37 @@ def test_array_copy():
         RawArray(data.astype(np.float32), info, copy=None)
 
 
+def test_array_init_kwargs():
+    """Test that constructor arguments do not retain stale array data."""
+    data = np.zeros((1, 1000))
+    data_ref = weakref.ref(data)
+    raw = RawArray(data, create_info(1, 1000.0, "eeg"))
+
+    init_kwargs = raw._init_kwargs
+    assert isinstance(init_kwargs, dict)
+    assert tuple(init_kwargs) == ("data", "info", "first_samp", "copy", "verbose")
+    assert init_kwargs["data"] is raw._data
+    del init_kwargs, data
+
+    raw.resample(500)
+    gc.collect()
+    assert data_ref() is None
+    assert raw._init_kwargs["data"] is raw._data
+
+    raw_copy = raw.copy()
+    assert raw_copy._init_kwargs["data"] is raw_copy._data
+    assert raw_copy._data is not raw._data
+
+    raw_reconstructed = RawArray(**raw._init_kwargs)
+    assert_allclose(raw_reconstructed.get_data(), raw.get_data())
+    assert repr(raw_reconstructed) == repr(raw)
+
+    raw_unpickled = pickle.loads(pickle.dumps(raw))
+    assert raw_unpickled._init_kwargs["data"] is raw_unpickled._data
+    assert_allclose(raw_unpickled.get_data(), raw.get_data())
+    assert repr(raw_unpickled) == repr(raw)
+
+
 @pytest.mark.slowtest
 def test_array_raw():
     """Test creating raw from array."""