Return noopmeter on invalid name getmeter (open-telemetry#2428)

.github/workflows/test.yml

@@ -10,7 +10,7 @@ env:
   # Otherwise, set variable to the commit of your branch on
   # opentelemetry-python-contrib which is compatible with these Core repo
   # changes.
-  CONTRIB_REPO_SHA: b541c59284100e617303a5c1f505ca2872045792
+  CONTRIB_REPO_SHA: ad2594e166bd7f4cd40780df418f82389de970a6
   # This is needed because we do not clone the core repo in contrib builds anymore.
   # When running contrib builds as part of core builds, we use actions/checkout@v2 which
   # does not set an environment variable (simply just runs tox), which is different when

opentelemetry-sdk/src/opentelemetry/sdk/_metrics/__init__.py

@@ -230,6 +230,10 @@ def get_meter(
             )
             return NoOpMeter(name, version=version, schema_url=schema_url)
 
+        if not name:
+            _logger.warning("Meter name cannot be None or empty.")
+            return NoOpMeter(name, version=version, schema_url=schema_url)
+
         info = InstrumentationInfo(name, version, schema_url)
         with self._meter_lock:
             if not self._meters.get(info):

opentelemetry-sdk/tests/metrics/test_metrics.py

@@ -17,6 +17,7 @@
 from unittest import TestCase
 from unittest.mock import MagicMock, Mock, patch
 
+from opentelemetry._metrics import NoOpMeter
 from opentelemetry.sdk._metrics import Meter, MeterProvider
 from opentelemetry.sdk._metrics.instrument import (
     Counter,
@@ -80,6 +81,28 @@ def test_get_meter(self):
         self.assertEqual(meter._instrumentation_info.version, "version")
         self.assertEqual(meter._instrumentation_info.schema_url, "schema_url")
 
+    def test_get_meter_empty(self):
+        """
+        `MeterProvider.get_meter` called with None or empty string as name
+        should return a NoOpMeter.
+        """
+
+        meter = MeterProvider().get_meter(
+            None,
+            version="version",
+            schema_url="schema_url",
+        )
+        self.assertIsInstance(meter, NoOpMeter)
+        self.assertEqual(meter._name, None)
+
+        meter = MeterProvider().get_meter(
+            "",
+            version="version",
+            schema_url="schema_url",
+        )
+        self.assertIsInstance(meter, NoOpMeter)
+        self.assertEqual(meter._name, "")
+
     def test_get_meter_duplicate(self):
         """
         Subsequent calls to `MeterProvider.get_meter` with the same arguments