Testing get_instance method of data_accessor

tests/gui/gui_specific/test_get_instance.py

@@ -0,0 +1,39 @@
+import pytest
+from taipy.gui.data.data_accessor import _DataAccessors, _InvalidDataAccessor
+from taipy.gui import Gui
+
+
+def test__get_instance_with_valid_data(gui: Gui):
+    """Test if __get_instance returns the correct accessor for valid data."""
+    data_accessors = _DataAccessors(gui)
+
+    # Simulate valid data being passed
+    data_accessors._DataAccessors__access_4_type = {int: "valid_accessor"} # type: ignore
+
+    result = data_accessors._DataAccessors__get_instance(123) # type: ignore
+    assert result == "valid_accessor"  # Valid accessor should be returned
+
+
+def test__get_instance_with_invalid_data(gui: Gui):
+    """Test if __get_instance handles invalid data correctly."""
+    data_accessors = _DataAccessors(gui)
+
+    # No valid data accessor, should return None
+    gui.handle_invalid_data = lambda x: None # type: ignore
+    result = data_accessors._DataAccessors__get_instance("invalid_data") # type: ignore
+
+    assert isinstance(result, _InvalidDataAccessor)  # Should return InvalidDataAccessor
+
+
+def test__get_instance_transformation_successful(gui: Gui):
+    """Test if __get_instance transforms invalid data correctly when callback is set."""
+    data_accessors = _DataAccessors(gui)
+
+    # Mock invalid data transformation to return valid data
+    gui.handle_invalid_data = lambda x: 123  # type: ignore # Transformation success
+    data_accessors._DataAccessors__access_4_type = {int: "valid_accessor"} # type: ignore
+
+    result = data_accessors._DataAccessors__get_instance("invalid_data") # type: ignore
+    assert (
+        result == "valid_accessor"
+    )  # Transformed data should now return the valid accessor