From fe90b66e549c3df3d213f5d7348df08af8aac546 Mon Sep 17 00:00:00 2001
From: Omry Yadan <omry@fb.com>
Date: Sun, 9 Feb 2020 18:37:02 -0800
Subject: [PATCH] allow passthrough of non primitive objects by name

---
 hydra/utils.py      | 19 +++++++++++++++----
 news/400.bugfix     |  1 +
 tests/test_utils.py | 16 ++++++++++++++++
 3 files changed, 32 insertions(+), 4 deletions(-)
 create mode 100644 news/400.bugfix

diff --git a/hydra/utils.py b/hydra/utils.py
index 0767a5869ba..72a65c4ca08 100644
--- a/hydra/utils.py
+++ b/hydra/utils.py
@@ -4,7 +4,7 @@
 from pathlib import Path
 from typing import Any
 
-from omegaconf import DictConfig, OmegaConf
+from omegaconf import DictConfig, OmegaConf, _utils
 
 from hydra.conf import PluginConf
 from hydra.core.hydra_config import HydraConfig
@@ -67,9 +67,20 @@ def instantiate(config: PluginConf, *args: Any, **kwargs: Any) -> Any:
         ), "Input config params are expected to be a mapping, found {}".format(
             type(config.params)
         )
-        params.merge_with(OmegaConf.create(kwargs))
-
-        return clazz(*args, **params)
+        primitives = {}
+        rest = {}
+        for k, v in kwargs.items():
+            if _utils._is_primitive_type(v) or isinstance(v, (dict, list)):
+                primitives[k] = v
+            else:
+                rest[k] = v
+        params.merge_with(OmegaConf.create(primitives))
+        final_kwargs = OmegaConf.to_container(params, resolve=True)
+        assert isinstance(final_kwargs, DictConfig)
+        for k, v in rest.items():
+            final_kwargs[k] = v
+
+        return clazz(*args, **final_kwargs)
     except Exception as e:
         log.error(f"Error instantiating '{classname}' : {e}")
         raise e
diff --git a/news/400.bugfix b/news/400.bugfix
new file mode 100644
index 00000000000..cf257c0d393
--- /dev/null
+++ b/news/400.bugfix
@@ -0,0 +1 @@
+Allow hydra.utils.instantiate() to accept non primitive objects for passthrough by name
diff --git a/tests/test_utils.py b/tests/test_utils.py
index 9d0384ba9b2..b54f8fb1bee 100644
--- a/tests/test_utils.py
+++ b/tests/test_utils.py
@@ -48,6 +48,16 @@ def __ne__(self, other: Any) -> Any:
         return NotImplemented
 
 
+class Foo:
+    def __init__(self, x: int) -> None:
+        self.x = x
+
+    def __eq__(self, other: Any) -> Any:
+        if isinstance(other, Foo):
+            return self.x == other.x
+        return False
+
+
 @pytest.mark.parametrize("path,expected_type", [("tests.test_utils.Bar", Bar)])  # type: ignore
 def test_get_class(path: str, expected_type: type) -> None:
     assert utils.get_class(path) == expected_type
@@ -103,6 +113,12 @@ def test_get_static_method(path: str, return_value: Any) -> None:
             {"a": 10, "d": 40},
             Bar(10, 200, 200, 40),
         ),
+        (
+            {"cls": "tests.test_utils.Bar", "params": {"b": 200, "c": "${params.b}"}},
+            None,
+            {"a": 10, "d": Foo(99)},
+            Bar(10, 200, 200, Foo(99)),
+        ),
     ],
 )
 def test_class_instantiate(