ENH: F remove value or property

Summary

Precondition for https://gitlab.indiscale.com/caosdb/customers/geomar/management/-/issues/110. Adds a function that removes a value from a property, and optionally, the property from the entity if it is empty afterwards. We used to implement this functionality in several customer-specific extensions, so I think it makes sense to have this upstream.

Focus

Check whether the behavior of the new function is reasonable also in the corner cases of list properties in which the value to be removed occurs more than once (i.e., remove "a" from ["a", "b", "a"]) and in case of an already empty property (remove "something" from None vs remove None from None).

Test Environment

Unit tests should be sufficient, but feel free to test it manually, too. Also check whether the docstring is understandable.

Check List for the Author

Please, prepare your MR for a review. Be sure to write a summary and a focus and create gitlab comments for the reviewer. They should guide the reviewer through the changes, explain your changes and also point out open questions. For further good practices have a look at our review guidelines

• All automated tests pass
• Reference related issues
• Up-to-date CHANGELOG.md (or not necessary)
• Up-to-date JSON schema (or not necessary)
• Appropriate user and developer documentation (or not necessary)
  • How do I use the software? Assume "stupid" users.
  • How do I develop or debug the software? Assume novice developers.
• Annotations in code (Gitlab comments)
  • Intent of new code
  • Problems with old code
  • Why this implementation?

Check List for the Reviewer

• I understand the intent of this MR
• All automated tests pass
• Up-to-date CHANGELOG.md (or not necessary)
• Appropriate user and developer documentation (or not necessary)
• The test environment setup works and the intended behavior is reproducible in the test environment
• In-code documentation and comments are up-to-date.
• Check: Are there specifications? Are they satisfied?

For further good practices have a look at our review guidelines.

unittests/test_property.py

 # -*- encoding: utf-8 -*-
 #
-# ** header v3.0
 # This file is a part of the CaosDB Project.
 #
 # Copyright (C) 2018 Research Group Biomedical Physics,
 # Max-Planck-Institute for Dynamics and Self-Organization Göttingen
-# Copyright (C) 2020 IndiScale GmbH <info@indiscale.com>
+# Copyright (C) 2020 - 2023 IndiScale GmbH <info@indiscale.com>
+# Copyright (C) 2023 Florian Spreckelsen <f.spreckelsen@indiscale.com>
 # Copyright (C) 2020 Timm Fitschen <t.fitschen@indiscale.com>
 #
 # This program is free software: you can redistribute it and/or modify
@@ -21,8 +21,6 @@
 # You should have received a copy of the GNU Affero General Public License
 # along with this program. If not, see <https://www.gnu.org/licenses/>.
 #
-# ** end header
-#
 """Tests for the Property class."""
 import os
 
@@ -138,3 +136,87 @@ def test_is_reference():
 
     # restore retrieve function with original
     Entity.retrieve = real_retrieve
+
+
+def test_remove_value_from_property():
+
+    rec = Record()
+    names_values_dtypes = [
+        ("testListProp1", [1, 2, 3], db.LIST(db.INTEGER)),
+        ("testListProp2", ["a", "b", "a"], db.LIST(db.TEXT)),
+        ("testScalarProp1", "bla", db.TEXT),
+        ("testScalarProp2", False, db.BOOLEAN),
+        ("testEmptyProp", None, db.REFERENCE),
+        ("testNoneListProp", [None, None], db.LIST(db.REFERENCE)),
+    ]
+    for name, value, dtype in names_values_dtypes:
+        rec.add_property(name=name, value=value, datatype=dtype)
+
+    # property doesn't exist, so do nothing
+    returned = rec.remove_value_from_property("nonexisting", "some_value")
+    assert returned is rec
+    for name, value, dtype in names_values_dtypes:
+        assert rec.get_property(name).value == value
+        assert rec.get_property(name).datatype == dtype
+
+    # value doesn't exist so nothing changes either
+    rec.remove_value_from_property("testListProp1", 0)
+    assert rec.get_property("testListProp1").value == [1, 2, 3]
+    assert rec.get_property("testListProp1").datatype == db.LIST(db.INTEGER)
+
+    returned = rec.remove_value_from_property("testScalarProp2", True)
+    assert returned is rec
+    assert rec.get_property("testScalarProp2").value is False
+    assert rec.get_property("testScalarProp2").datatype == db.BOOLEAN
+
+    # Simple removals from lists without emptying them
+    rec.remove_value_from_property("testListProp1", 1)
+    assert rec.get_property("testListProp1").value == [2, 3]
+
+    rec.remove_value_from_property("testListProp1", 2)
+    assert rec.get_property("testListProp1").value == [3]
+
+    # similarly to Python's `list.remove()`, only remove first occurrance
+    rec.remove_value_from_property("testListProp2", "a")
+    assert rec.get_property("testListProp2").value == ["b", "a"]
+
+    # default is to remove an empty property:
+    rec.remove_value_from_property("testListProp1", 3)
+    assert rec.get_property("testListProp1") is None
+
+    rec.remove_value_from_property("testScalarProp1", "bla")
+    assert rec.get_property("testScalarProp1") is None
+
+    # don't remove if `remove_if_empty_afterwards=False`
+    rec.remove_value_from_property("testListProp2", "b")
+    rec.remove_value_from_property("testListProp2", "a", remove_if_empty_afterwards=False)
+    assert rec.get_property("testListProp2") is not None
+    assert rec.get_property("testListProp2").value is None
+    assert rec.get_property("testListProp2").datatype == db.LIST(db.TEXT)
+
+    rec.remove_value_from_property("testScalarProp2", False, remove_if_empty_afterwards=False)
+    assert rec.get_property("testScalarProp2") is not None
+    assert rec.get_property("testScalarProp2").value is None
+    assert rec.get_property("testScalarProp2").datatype == db.BOOLEAN
+
+    # Special case of an already empty property: It is not empty because a value
+    # was removed by `remove_value_from_property` but never had a value in the
+    # first place. So even `remove_if_empty_afterwards=True` should not lead to
+    # its removal.
+    rec.remove_value_from_property("testEmptyProp", 1234, remove_if_empty_afterwards=True)
+    assert rec.get_property("testEmptyProp") is not None
+    assert rec.get_property("testEmptyProp").value is None
+    assert rec.get_property("testEmptyProp").datatype == db.REFERENCE
+
+    # Corner case of corner case: remove with `value=None` and
+    # `remove_if_empty_afterwards=True` keeps the empty property.
+    rec.remove_value_from_property("testEmptyProp", None, remove_if_empty_afterwards=True)
+    assert rec.get_property("testEmptyProp") is not None
+    assert rec.get_property("testEmptyProp").value is None
+    assert rec.get_property("testEmptyProp").datatype == db.REFERENCE
+
+    # Remove `None` from list `[None, None]`
+    rec.remove_value_from_property("testNoneListProp", None, remove_if_empty_afterwards=True)
+    assert rec.get_property("testNoneListProp") is not None
+    assert rec.get_property("testNoneListProp").value == [None]
+    assert rec.get_property("testNoneListProp").datatype == db.LIST(db.REFERENCE)