refactor(debugging): make safety module internal (#6810)

The safety submodule of `ddtrace.debugging` has been made public
(according to the naming conventions) by accident. The API of this
module is not documented and we do not expect any usage outside the
library itself.

## Checklist

- [x] Change(s) are motivated and described in the PR description.
- [x] Testing strategy is described if automated tests are not included
in the PR.
- [x] Risk is outlined (performance impact, potential for breakage,
maintainability, etc).
- [x] Change is maintainable (easy to change, telemetry, documentation).
- [x] [Library release note
guidelines](https://ddtrace.readthedocs.io/en/stable/releasenotes.html)
are followed. If no release note is required, add label
`changelog/no-changelog`.
- [x] Documentation is included (in-code, generated user docs, [public
corp docs](https://github.com/DataDog/documentation/)).
- [x] Backport labels are set (if
[applicable](https://ddtrace.readthedocs.io/en/latest/contributing.html#backporting))

## Reviewer Checklist

- [x] Title is accurate.
- [x] No unnecessary changes are introduced.
- [x] Description motivates each change.
- [x] Avoids breaking
[API](https://ddtrace.readthedocs.io/en/stable/versioning.html#interfaces)
changes unless absolutely necessary.
- [x] Testing strategy adequately addresses listed risk(s).
- [x] Change is maintainable (easy to change, telemetry, documentation).
- [x] Release note makes sense to a user of the library.
- [x] Reviewer has explicitly acknowledged and discussed the performance
implications of this PR as reported in the benchmarks PR comment.
- [x] Backport labels are set in a manner that is consistent with the
[release branch maintenance
policy](https://ddtrace.readthedocs.io/en/latest/contributing.html#backporting)
- [x] If this PR touches code that signs or publishes builds or
packages, or handles credentials of any kind, I've requested a review
from `@DataDog/security-design-and-guidance`.
- [x] This PR doesn't touch any of that.

---------

Co-authored-by: Yun Kim <[email protected]>
Co-authored-by: Yun Kim <[email protected]>

ddtrace/debugging/_expressions.py

@@ -40,7 +40,7 @@
 from bytecode import Compare
 from bytecode import Instr
 
-from ddtrace.debugging.safety import safe_getitem
+from ddtrace.debugging._safety import safe_getitem
 from ddtrace.internal.compat import PYTHON_VERSION_INFO as PY
 
 

ddtrace/debugging/_signal/model.py

@@ -15,7 +15,7 @@
 import six
 
 from ddtrace.context import Context
-from ddtrace.debugging import safety
+from ddtrace.debugging import _safety
 from ddtrace.debugging._expressions import DDExpressionEvaluationError
 from ddtrace.debugging._probe.model import FunctionLocationMixin
 from ddtrace.debugging._probe.model import LineLocationMixin
@@ -83,7 +83,7 @@ def _eval_condition(self, _locals=None):
         return False
 
     def _enrich_args(self, retval, exc_info, duration):
-        _locals = list(self.args or safety.get_args(self.frame))
+        _locals = list(self.args or _safety.get_args(self.frame))
         _locals.append(("@duration", duration / 1e6))  # milliseconds
         if exc_info[1] is None:
             _locals.append(("@return", retval))

ddtrace/debugging/_signal/snapshot.py

@@ -8,7 +8,7 @@
 
 import attr
 
-from ddtrace.debugging import safety
+from ddtrace.debugging import _safety
 from ddtrace.debugging._expressions import DDExpressionEvaluationError
 from ddtrace.debugging._probe.model import CaptureLimits
 from ddtrace.debugging._probe.model import DEFAULT_CAPTURE_LIMITS
@@ -144,7 +144,7 @@ def enter(self):
 
         probe = self.probe
         frame = self.frame
-        _args = list(self.args or safety.get_args(frame))
+        _args = list(self.args or _safety.get_args(frame))
 
         if probe.evaluate_at == ProbeEvaluateTimingForMethod.EXIT:
             return
@@ -190,7 +190,7 @@ def exit(self, retval, exc_info, duration):
 
         if probe.take_snapshot:
             self.return_capture = _capture_context(
-                self.args or safety.get_args(self.frame), _locals, exc_info, limits=probe.limits
+                self.args or _safety.get_args(self.frame), _locals, exc_info, limits=probe.limits
             )
         self.duration = duration
         self.state = SignalState.DONE
@@ -213,8 +213,8 @@ def line(self):
                 return
 
             self.line_capture = _capture_context(
-                self.args or safety.get_args(frame),
-                safety.get_locals(frame),
+                self.args or _safety.get_args(frame),
+                _safety.get_locals(frame),
                 sys.exc_info(),
                 limits=probe.limits,
             )

ddtrace/debugging/_signal/utils.py

@@ -13,7 +13,7 @@
 from ddtrace.debugging._probe.model import MAXLEN
 from ddtrace.debugging._probe.model import MAXLEVEL
 from ddtrace.debugging._probe.model import MAXSIZE
-from ddtrace.debugging.safety import get_fields
+from ddtrace.debugging._safety import get_fields
 from ddtrace.internal.compat import BUILTIN_CONTAINER_TYPES
 from ddtrace.internal.compat import BUILTIN_SIMPLE_TYPES
 from ddtrace.internal.compat import CALLABLE_TYPES

tests/debugging/test_safety.py

@@ -4,15 +4,15 @@
 
 import pytest
 
-from ddtrace.debugging import safety
+from ddtrace.debugging import _safety
 
 
 def test_get_args():
     def assert_args(args):
-        assert set(dict(safety.get_args(inspect.currentframe().f_back)).keys()) == args
+        assert set(dict(_safety.get_args(inspect.currentframe().f_back)).keys()) == args
 
     def assert_locals(_locals):
-        assert set(dict(safety.get_locals(inspect.currentframe().f_back)).keys()) == _locals
+        assert set(dict(_safety.get_locals(inspect.currentframe().f_back)).keys()) == _locals
 
     def arg_and_kwargs(a, **kwargs):
         assert_args({"a", "kwargs"})
@@ -55,7 +55,7 @@ def property_with_side_effect(self):
 
 
 def test_get_fields_side_effects():
-    assert safety.get_fields(SideEffects()) == {}
+    assert _safety.get_fields(SideEffects()) == {}
 
 
 # ---- Slots ----
@@ -75,8 +75,8 @@ def __init__(self):
             super(B, self).__init__()
             self.b = "b"
 
-    assert safety.get_fields(A()) == {"a": "a"}
-    assert safety.get_fields(B()) == {"a": "a", "b": "b"}
+    assert _safety.get_fields(A()) == {"a": "a"}
+    assert _safety.get_fields(B()) == {"a": "a", "b": "b"}
 
 
 def test_safe_dict():
@@ -87,4 +87,4 @@ def __dict__(self):
             raise NotImplementedError()
 
     with pytest.raises(AttributeError):
-        safety._safe_dict(Foo())
+        _safety._safe_dict(Foo())