IDProps: Make 'dynamic RNA' IDProperties statically typed.

All IDProperties generated as part of 'storage backend' for dynamic RNA
properties are now statically typed.

Also adds some basic unittests for the new statically typed IDProperty
system, based on py-defined RNA data.

Ref. #122743.

tests/python/bl_pyapi_idprop.py

@@ -254,6 +254,88 @@ class TestIdPropertyUIData(TestHelper, unittest.TestCase):
             self.assertEqual(self.id.path_resolve('["%s"]' % bpy.utils.escape_identifier(self.key_id)), 'A')
 
 
+# Check statically typed underlying IDProperties storage for dynamic RNA properties.
+class TestIdPropertyDynamicRNA(TestHelper, unittest.TestCase):
+
+    class TestDynRNAClass(bpy.types.PropertyGroup):
+        string_prop: bpy.props.StringProperty()
+        int_prop: bpy.props.IntProperty()
+        float_array_prop: bpy.props.FloatVectorProperty(size=[3])
+
+    def setUp(self):
+        super().setUp()
+        bpy.utils.register_class(self.TestDynRNAClass)
+        assert(type(self.id) == bpy.types.Scene)
+        bpy.types.Scene.dynrna_prop = bpy.props.PointerProperty(type=self.TestDynRNAClass)
+        assert(hasattr(self.id, "dynrna_prop"))
+
+    def tearDown(self):
+        del bpy.types.Scene.dynrna_prop
+        bpy.utils.unregister_class(self.TestDynRNAClass)
+        super().tearDown()
+
+    def test_dynamic_rna_basics(self):
+        # The IDP_Group matching a registered RNA Pointer property to a registered
+        # PropertyGroup type always exists.
+        self.assertTrue('dynrna_prop' in self.id)
+        # However, the underlying idprop data for each property of the PropertyGroup
+        # does not exist untill set through an RNA property access.
+        self.assertTrue(len(self.id['dynrna_prop']) == 0)
+
+        self.id.dynrna_prop.string_prop = "Test String"
+        self.assertTrue(len(self.id['dynrna_prop']) == 1)
+        self.assertEqual(self.id.dynrna_prop.string_prop, self.id['dynrna_prop']['string_prop'])
+        self.id['dynrna_prop']['string_prop'] = "String test"
+        self.assertEqual(self.id.dynrna_prop.string_prop, self.id['dynrna_prop']['string_prop'])
+
+        self.id.dynrna_prop.int_prop = 1
+        self.assertTrue(len(self.id['dynrna_prop']) == 2)
+        self.assertEqual(self.id.dynrna_prop.int_prop, self.id['dynrna_prop']['int_prop'])
+        self.id['dynrna_prop']['int_prop'] = 33
+        self.assertEqual(self.id.dynrna_prop.int_prop, self.id['dynrna_prop']['int_prop'])
+
+        self.id.dynrna_prop.float_array_prop = [1.0, 2.0, 3.0]
+        self.assertTrue(len(self.id['dynrna_prop']) == 3)
+        self.assertEqual(list(self.id.dynrna_prop.float_array_prop), list(self.id['dynrna_prop']['float_array_prop']))
+        self.id['dynrna_prop']['float_array_prop'] = [0.1, 1.0, 10.0]
+        self.assertEqual(list(self.id.dynrna_prop.float_array_prop), list(self.id['dynrna_prop']['float_array_prop']))
+
+    def test_static_type(self):
+        # Check that the idproperty behind the defined RNA ones are statically typed, and cannot be
+        # assigned random other types of values.
+        self.id.dynrna_prop.string_prop = "Test String"
+        self.id.dynrna_prop.int_prop = 1
+        self.id.dynrna_prop.float_array_prop = [1.0, 2.0, 3.0]
+
+        with self.assertRaises(TypeError):
+            self.id['dynrna_prop']['string_prop'] = b"Test String"
+
+        # Supported conversion from bool to int.
+        self.id['dynrna_prop']['int_prop'] = False
+        self.assertEqual(self.id['dynrna_prop']['int_prop'], 0)
+        self.assertEqual(self.id.dynrna_prop.int_prop, self.id['dynrna_prop']['int_prop'])
+        self.assertEqual(type(self.id['dynrna_prop']['int_prop']), int)
+        with self.assertRaises(TypeError):
+            self.id['dynrna_prop']['int_prop'] = 2.5
+        with self.assertRaises(TypeError):
+            self.id['dynrna_prop']['int_prop'] = "100"
+
+        mixed_array = [5, 2.5, 2]
+        self.id['dynrna_prop']['float_array_prop'] = mixed_array
+        self.assertEqual(list(self.id['dynrna_prop']['float_array_prop']), mixed_array)
+        self.assertEqual(list(self.id.dynrna_prop.float_array_prop), list(self.id['dynrna_prop']['float_array_prop']))
+        self.assertTrue(all((type(i) is float for i in self.id['dynrna_prop']['float_array_prop'])))
+        with self.assertRaises(TypeError):
+            self.id['dynrna_prop']['float_array_prop'] = 2.5
+        with self.assertRaises(TypeError):
+            self.id['dynrna_prop']['float_array_prop'] = [True, False, False]
+        # Length of the array is also considered as static/fixed.
+        with self.assertRaises(TypeError):
+            self.id['dynrna_prop']['float_array_prop'] = [5.0, 2.5]
+        with self.assertRaises(TypeError):
+            self.id['dynrna_prop']['float_array_prop'] = [1.0, 10.0, 100.0, 0.1]
+
+
 class TestIdPropertyGroupView(TestHelper, unittest.TestCase):
 
     def test_type(self):