🎨 Make the default record writing space consistent

lamindb/models/sqlrecord.py

@@ -257,8 +257,9 @@ def single_space(self) -> bool | Space:
 
         Can only be set if the `SQLRecord` class inherits from `HasType` and `.is_type` is `True`.
 
-        This only affects updates to objects that will start to throw an error upon `INSERT` or `UPDATE`
-        if their space does not match the enforced space. Existing objects are not affected.
+        This affects creates and updates: new objects without an explicit `space` default to the
+        enforced space, and `INSERT` / `UPDATE` throw if their space does not match. Existing
+        objects are not rewritten when the setting changes.
 
         The enforced space can be configured in 2 ways:
 
@@ -341,6 +342,28 @@ def single_space(self, value: bool | Space) -> None:
                 self._sqlrecord._aux = None
 
 
+def resolve_space_from_single_space_policy(type_record: HasType) -> Space | None:
+    """Return the write space enforced by a type's `_aux["ss"]`, if any.
+
+    Mirrors the frontend single-space policy used for default write-space selection:
+
+    - `_aux.ss = 1` or `"1"` → the type's own owning space
+    - `_aux.ss = "<space uid>"` → that exact space
+    - missing / unset → ``None`` (caller keeps context / settings / ``all`` fallback)
+    """
+    aux = getattr(type_record, "_aux", None)
+    if not aux:
+        return None
+    ss = aux.get("ss")
+    if ss is None:
+        return None
+    if ss == 1 or ss == "1":
+        return getattr(type_record, "space", None)
+    if isinstance(ss, str) and ss:
+        return Space.get(ss)
+    return None
+
+
 def deferred_attribute__repr__(self):
     return f"FieldAttr({self.field.model.__name__}.{self.field.name})"
 
@@ -1185,7 +1208,9 @@ def resolve_fk_or_id(field_name: str) -> bool:
                     from lamindb import context as run_context
 
                     # Precedence is uniform across SQLRecord children:
-                    # explicit `<fk>_id` or `<fk>` (mutually exclusive) > context/settings fallback.
+                    # explicit `<fk>_id` or `<fk>` (mutually exclusive)
+                    # > type `_aux.ss` single-space policy
+                    # > context/settings fallback.
                     has_explicit_space = resolve_fk_or_id("space")
                     if run_context.space is not None:
                         current_space = run_context.space
@@ -1195,7 +1220,15 @@ def resolve_fk_or_id(field_name: str) -> bool:
                         current_space = None
 
                     if not has_explicit_space:
-                        if current_space is not None:
+                        policy_space = None
+                        type_record = kwargs.get("type")
+                        if isinstance(type_record, HasType):
+                            policy_space = resolve_space_from_single_space_policy(
+                                type_record
+                            )
+                        if policy_space is not None:
+                            kwargs["space"] = policy_space
+                        elif current_space is not None:
                             kwargs["space"] = current_space
                         elif kwargs.get("space") is None:
                             kwargs.pop("space", None)

tests/pydata/test_record_basics.py

@@ -744,6 +744,12 @@ def test_single_space_enforces_type_space_or_specific_space():
     assert constrained_type._aux is not None
     assert constrained_type._aux.get("ss") == 1
 
+    # Without an explicit space, default to the type's owning space.
+    auto_type_space_record = ln.Record(
+        name="auto_type_space_record", type=constrained_type
+    ).save()
+    assert auto_type_space_record.space_id == constrained_type.space_id
+
     constrained_type.settings.single_space = restricted_space
     constrained_type.save()
     constrained_type.refresh_from_db()
@@ -753,6 +759,12 @@ def test_single_space_enforces_type_space_or_specific_space():
     assert constrained_type._aux is not None
     assert constrained_type._aux.get("ss") == restricted_space.uid
 
+    # Exact-space policy also defaults when space is omitted.
+    auto_exact_space_record = ln.Record(
+        name="auto_exact_space_record", type=constrained_type
+    ).save()
+    assert auto_exact_space_record.space_id == restricted_space.id
+
     valid_record = ln.Record(
         name="same_space_record", type=constrained_type, space=restricted_space
     ).save()
@@ -763,7 +775,11 @@ def test_single_space_enforces_type_space_or_specific_space():
     assert "record space must match locked type space" in error.exconly()
 
     with pytest.raises(InternalError) as error:
-        ln.Record(name="different_space_record", type=constrained_type).save()
+        ln.Record(
+            name="different_space_record",
+            type=constrained_type,
+            space=ln.Space.get(1),
+        ).save()
     assert "record space must match locked type space" in error.exconly()
 
     constrained_type.settings.single_space = True
@@ -775,7 +791,9 @@ def test_single_space_enforces_type_space_or_specific_space():
 
     with pytest.raises(InternalError) as error:
         ln.Record(
-            name="different_space_record_type_space_only", type=constrained_type
+            name="different_space_record_type_space_only",
+            type=constrained_type,
+            space=ln.Space.get(1),
         ).save()
     assert "record space must match locked type space" in error.exconly()
 
@@ -792,6 +810,8 @@ def test_single_space_enforces_type_space_or_specific_space():
 
     unconstrained_record.delete(permanent=True)
     unconstrained_record_2.delete(permanent=True)
+    auto_type_space_record.delete(permanent=True)
+    auto_exact_space_record.delete(permanent=True)
     valid_record.delete(permanent=True)
     constrained_type.delete(permanent=True)
     restricted_space.delete(permanent=True)