Fix Loguru Instrumentation for v0.7.0 (#798)

* Add autosignature implementation

* Fix loguru with auto-signature

* [Mega-Linter] Apply linters fixes

* Fix tests for Py2

* [Mega-Linter] Apply linters fixes

* Bump tests

* Remove unwrap from signature utils

* Fix arg unpacking

* Remove unwrap arg from bind_args

* Fix linter errors

---------

Co-authored-by: TimPansino <TimPansino@users.noreply.github.com>
Co-authored-by: Lalleh Rafeei <lrafeei@newrelic.com>

newrelic/common/signature.py

@@ -0,0 +1,31 @@
+# Copyright 2010 New Relic, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from newrelic.packages import six
+
+if six.PY3:
+    from inspect import Signature
+
+    def bind_args(func, args, kwargs):
+        """Bind arguments and apply defaults to missing arugments for a callable."""
+        bound_args = Signature.from_callable(func).bind(*args, **kwargs)
+        bound_args.apply_defaults()
+        return bound_args.arguments
+
+else:
+    from inspect import getcallargs
+
+    def bind_args(func, args, kwargs):
+        """Bind arguments and apply defaults to missing arugments for a callable."""
+        return getcallargs(func, *args, **kwargs)

newrelic/hooks/logger_loguru.py

@@ -18,15 +18,18 @@
 from newrelic.api.application import application_instance
 from newrelic.api.transaction import current_transaction, record_log_event
 from newrelic.common.object_wrapper import wrap_function_wrapper
+from newrelic.common.signature import bind_args
 from newrelic.core.config import global_settings
 from newrelic.hooks.logger_logging import add_nr_linking_metadata
 from newrelic.packages import six
 
-_logger = logging.getLogger(__name__) 
+_logger = logging.getLogger(__name__)
 is_pypy = hasattr(sys, "pypy_version_info")
 
+
 def loguru_version():
     from loguru import __version__
+
     return tuple(int(x) for x in __version__.split("."))
 
 
@@ -54,7 +57,7 @@ def _nr_log_forwarder(message_instance):
                 if application and application.enabled:
                     application.record_custom_metric("Logging/lines", {"count": 1})
                     application.record_custom_metric("Logging/lines/%s" % level_name, {"count": 1})
-            
+
         if settings.application_logging.forwarding and settings.application_logging.forwarding.enabled:
             try:
                 record_log_event(message, level_name, int(record["time"].timestamp()))
@@ -64,14 +67,13 @@ def _nr_log_forwarder(message_instance):
 
 ALLOWED_LOGURU_OPTIONS_LENGTHS = frozenset((8, 9))
 
-def bind_log(level_id, static_level_no, from_decorator, options, message, args, kwargs):
-    assert len(options) in ALLOWED_LOGURU_OPTIONS_LENGTHS  # Assert the options signature we expect
-    return level_id, static_level_no, from_decorator, list(options), message, args, kwargs
-
 
 def wrap_log(wrapped, instance, args, kwargs):
     try:
-        level_id, static_level_no, from_decorator, options, message, subargs, subkwargs = bind_log(*args, **kwargs)
+        bound_args = bind_args(wrapped, args, kwargs)
+        options = bound_args["options"] = list(bound_args["options"])
+        assert len(options) in ALLOWED_LOGURU_OPTIONS_LENGTHS  # Assert the options signature we expect
+
         options[-2] = nr_log_patcher(options[-2])
         # Loguru looks into the stack trace to find the caller's module and function names.
         # options[1] tells loguru how far up to look in the stack trace to find the caller.
@@ -87,14 +89,14 @@ def wrap_log(wrapped, instance, args, kwargs):
         _logger.debug("Exception in loguru handling: %s" % str(e))
         return wrapped(*args, **kwargs)
     else:
-        return wrapped(level_id, static_level_no, from_decorator, options, message, subargs, subkwargs)
+        return wrapped(**bound_args)
 
 
 def nr_log_patcher(original_patcher=None):
     def _nr_log_patcher(record):
         if original_patcher:
             record = original_patcher(record)
-        
+
         transaction = current_transaction()
 
         if transaction:

tests/agent_unittests/test_signature.py

@@ -0,0 +1,31 @@
+# Copyright 2010 New Relic, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import pytest
+
+from newrelic.common.signature import bind_args
+
+
+@pytest.mark.parametrize(
+    "func,args,kwargs,expected",
+    [
+        (lambda x, y: None, (1,), {"y": 2}, {"x": 1, "y": 2}),
+        (lambda x=1, y=2: None, (1,), {"y": 2}, {"x": 1, "y": 2}),
+        (lambda x=1: None, (), {}, {"x": 1}),
+    ],
+    ids=("posargs", "kwargs", "defaults"),
+)
+def test_signature_binding(func, args, kwargs, expected):
+    bound_args = bind_args(func, args, kwargs)
+    assert bound_args == expected