Consider empty bucket boundaries as valid

Author: xrmx

opentelemetry-sdk/src/opentelemetry/sdk/metrics/_internal/__init__.py

@@ -204,15 +204,17 @@ def create_histogram(
     ) -> APIHistogram:
         if explicit_bucket_boundaries_advisory is not None:
             invalid_advisory = False
-            try:
-                invalid_advisory = not (
-                    explicit_bucket_boundaries_advisory
-                    and all(
-                        isinstance(e, (float, int))
-                        for e in explicit_bucket_boundaries_advisory
+            if isinstance(explicit_bucket_boundaries_advisory, Sequence):
+                try:
+                    invalid_advisory = not (
+                        all(
+                            isinstance(e, (float, int))
+                            for e in explicit_bucket_boundaries_advisory
+                        )
                     )
-                )
-            except (KeyError, TypeError):
+                except (KeyError, TypeError):
+                    invalid_advisory = True
+            else:
                 invalid_advisory = True
 
             if invalid_advisory:

opentelemetry-sdk/tests/metrics/integration_test/test_histogram_advisory_explicit_buckets.py

@@ -49,6 +49,30 @@ def test_default(self):
             metric.data.data_points[0].explicit_bounds, (1.0, 2.0, 3.0)
         )
 
+    def test_empty_buckets(self):
+        reader = InMemoryMetricReader()
+        meter_provider = MeterProvider(
+            metric_readers=[reader],
+        )
+        meter = meter_provider.get_meter("testmeter")
+        histogram = meter.create_histogram(
+            "testhistogram",
+            explicit_bucket_boundaries_advisory=[],
+        )
+        histogram.record(1, {"label": "value"})
+        histogram.record(2, {"label": "value"})
+        histogram.record(3, {"label": "value"})
+
+        metrics = reader.get_metrics_data()
+        self.assertEqual(len(metrics.resource_metrics), 1)
+        self.assertEqual(len(metrics.resource_metrics[0].scope_metrics), 1)
+        self.assertEqual(
+            len(metrics.resource_metrics[0].scope_metrics[0].metrics), 1
+        )
+        metric = metrics.resource_metrics[0].scope_metrics[0].metrics[0]
+        self.assertEqual(metric.name, "testhistogram")
+        self.assertEqual(metric.data.data_points[0].explicit_bounds, ())
+
     def test_view_default_aggregation(self):
         reader = InMemoryMetricReader()
         view = View(instrument_name="testhistogram")

opentelemetry-sdk/tests/metrics/test_metrics.py

@@ -531,7 +531,7 @@ def test_create_histogram_with_advisory(self):
 
     def test_create_histogram_advisory_validation(self):
         advisories = [
-            {"explicit_bucket_boundaries_advisory": []},
+            {"explicit_bucket_boundaries_advisory": "hello"},
             {"explicit_bucket_boundaries_advisory": ["1"]},
         ]
         for advisory in advisories: