Optional ReplaceableBase

Summary: Allow things like `renderer:Optional[BaseRenderer]` in configurables.

Reviewed By: davnov134

Differential Revision: D35118339

fbshipit-source-id: 1219321b2817ed4b26fe924c6d6f73887095c985

tests/implicitron/test_config.py

@@ -14,7 +14,9 @@ from omegaconf import DictConfig, ListConfig, OmegaConf, ValidationError
 from pytorch3d.implicitron.tools.config import (
     Configurable,
     ReplaceableBase,
+    _get_type_to_process,
     _is_actually_dataclass,
+    _ProcessType,
     _Registry,
     expand_args_fields,
     get_default_args,
@@ -94,6 +96,19 @@ class TestConfig(unittest.TestCase):
         self.assertFalse(_is_actually_dataclass(B))
         self.assertTrue(is_dataclass(B))
 
+    def test_get_type_to_process(self):
+        gt = _get_type_to_process
+        self.assertIsNone(gt(int))
+        self.assertEqual(gt(Fruit), (Fruit, _ProcessType.REPLACEABLE))
+        self.assertEqual(
+            gt(Optional[Fruit]), (Fruit, _ProcessType.OPTIONAL_REPLACEABLE)
+        )
+        self.assertEqual(gt(MainTest), (MainTest, _ProcessType.CONFIGURABLE))
+        self.assertIsNone(gt(Optional[int]))
+        self.assertIsNone(gt(Optional[MainTest]))
+        self.assertIsNone(gt(Tuple[Fruit]))
+        self.assertIsNone(gt(Tuple[Fruit, Animal]))
+
     def test_simple_replacement(self):
         struct = get_default_args(MainTest)
         struct.n_ids = 9780
@@ -247,6 +262,7 @@ class TestConfig(unittest.TestCase):
         self.assertEqual(container.fruit_Pear_args.n_pips, 13)
 
     def test_inheritance(self):
+        # Also exercises optional replaceables
         class FruitBowl(ReplaceableBase):
             main_fruit: Fruit
             main_fruit_class_type: str = "Orange"
@@ -255,8 +271,10 @@ class TestConfig(unittest.TestCase):
                 raise ValueError("This doesn't get called")
 
         class LargeFruitBowl(FruitBowl):
-            extra_fruit: Fruit
+            extra_fruit: Optional[Fruit]
             extra_fruit_class_type: str = "Kiwi"
+            no_fruit: Optional[Fruit]
+            no_fruit_class_type: Optional[str] = None
 
             def __post_init__(self):
                 run_auto_creation(self)
@@ -267,6 +285,22 @@ class TestConfig(unittest.TestCase):
         large = LargeFruitBowl(**large_args)
         self.assertIsInstance(large.main_fruit, Orange)
         self.assertIsInstance(large.extra_fruit, Kiwi)
+        self.assertIsNone(large.no_fruit)
+        self.assertIn("no_fruit_Kiwi_args", large_args)
+
+        remove_unused_components(large_args)
+        large2 = LargeFruitBowl(**large_args)
+        self.assertIsInstance(large2.main_fruit, Orange)
+        self.assertIsInstance(large2.extra_fruit, Kiwi)
+        self.assertIsNone(large2.no_fruit)
+        needed_args = [
+            "extra_fruit_Kiwi_args",
+            "extra_fruit_class_type",
+            "main_fruit_Orange_args",
+            "main_fruit_class_type",
+            "no_fruit_class_type",
+        ]
+        self.assertEqual(sorted(large_args.keys()), needed_args)
 
     def test_inheritance2(self):
         # This is a case where a class could contain an instance