--cfg=hydra for read-only top-level config

facebookresearch · Apr 6, 2021 · 836c75c · 836c75c
1 parent 8e078bf
commit 836c75c
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Showing 2 changed files with 53 additions and 11 deletions.
diff --git a/hydra/_internal/hydra.py b/hydra/_internal/hydra.py
@@ -7,7 +7,7 @@
 from collections import defaultdict
 from typing import Any, Callable, DefaultDict, List, Optional, Sequence, Type, Union
 
-from omegaconf import Container, DictConfig, OmegaConf, open_dict
+from omegaconf import Container, DictConfig, OmegaConf, open_dict, read_write
 
 from hydra._internal.utils import get_column_widths, run_and_report
 from hydra.core.config_loader import ConfigLoader
@@ -136,13 +136,14 @@ def multirun(
     @staticmethod
     def get_sanitized_hydra_cfg(src_cfg: DictConfig) -> DictConfig:
         cfg = copy.deepcopy(src_cfg)
-        with open_dict(cfg):
-            for key in list(cfg.keys()):
-                if key != "hydra":
-                    del cfg[key]
-        with open_dict(cfg.hydra):
-            del cfg.hydra["hydra_help"]
-            del cfg.hydra["help"]
+        with read_write(cfg):
+            with open_dict(cfg):
+                for key in list(cfg.keys()):
+                    if key != "hydra":
+                        del cfg[key]
+            with open_dict(cfg.hydra):
+                del cfg.hydra["hydra_help"]
+                del cfg.hydra["help"]
         return cfg
 
     def _get_cfg(
@@ -160,8 +161,9 @@ def _get_cfg(
             with_log_configuration=with_log_configuration,
         )
         if cfg_type == "job":
-            with open_dict(cfg):
-                del cfg["hydra"]
+            with read_write(cfg):
+                with open_dict(cfg):
+                    del cfg["hydra"]
         elif cfg_type == "hydra":
             cfg = self.get_sanitized_hydra_cfg(cfg)
         return cfg

diff --git a/tests/test_hydra.py b/tests/test_hydra.py
@@ -1227,10 +1227,50 @@ def test_hydra_main_without_config_path(tmpdir: Path) -> None:
           @hydra.main()
         """
     )
-
     assert_regex_match(
         from_line=expected,
         to_line=err,
         from_name="Expected error",
         to_name="Actual error",
     )
+
+
+@mark.parametrize(
+    "overrides,expected",
+    [
+        (
+            ["--cfg", "job"],
+            dedent(
+                """\
+                baud_rate: 19200
+                data_bits: 8
+                stop_bits: 1
+                """
+            ),
+        ),
+        (
+            ["--cfg", "hydra", "-p", "hydra.env"],
+            dedent(
+                """\
+                # @package hydra.env
+                {}
+                """
+            ),
+        ),
+    ],
+)
+def test_frozen_primary_config(
+    tmpdir: Path, overrides: List[str], expected: Any
+) -> None:
+    cmd = [
+        "examples/patterns/write_protect_config_node/frozen.py",
+        f"hydra.run.dir={tmpdir}",
+    ]
+    cmd.extend(overrides)
+    ret, _err = run_python_script(cmd)
+    assert_regex_match(
+        from_line=expected,
+        to_line=ret,
+        from_name="Expected output",
+        to_name="Actual output",
+    )