Add missing to_json methods

Fixes #2716

CHANGELOG.md

@@ -7,6 +7,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased](https://github.com/open-telemetry/opentelemetry-python/compare/v1.12.0rc1-0.31b0...HEAD)
 
+- Add missing `to_json` methods
+  ([#2722](https://github.com/open-telemetry/opentelemetry-python/pull/2722)
 - Fix LogEmitterProvider.force_flush hanging randomly
   ([#2714](https://github.com/open-telemetry/opentelemetry-python/pull/2714))
 

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

@@ -15,8 +15,8 @@
 # pylint: disable=unused-import
 
 from dataclasses import asdict, dataclass
-from json import dumps
-from typing import Sequence, Union
+from json import dumps, loads
+from typing import Optional, Sequence, Union
 
 # This kind of import is needed to avoid Sphinx errors.
 import opentelemetry.sdk.metrics._internal
@@ -36,6 +36,29 @@ class NumberDataPoint:
     time_unix_nano: int
     value: Union[int, float]
 
+    def to_json(self) -> str:
+        return dumps(asdict(self))
+
+
+@dataclass(frozen=True)
+class HistogramDataPoint:
+    """Single data point in a timeseries that describes the time-varying scalar
+    value of a metric.
+    """
+
+    attributes: Attributes
+    start_time_unix_nano: int
+    time_unix_nano: int
+    count: int
+    sum: Union[int, float]
+    bucket_counts: Sequence[int]
+    explicit_bounds: Sequence[float]
+    min: float
+    max: float
+
+    def to_json(self) -> str:
+        return dumps(asdict(self))
+
 
 @dataclass(frozen=True)
 class Sum:
@@ -51,9 +74,10 @@ class Sum:
     def to_json(self) -> str:
         return dumps(
             {
-                "data_points": dumps(
-                    [asdict(data_point) for data_point in self.data_points]
-                ),
+                "data_points": [
+                    loads(data_point.to_json())
+                    for data_point in self.data_points
+                ],
                 "aggregation_temporality": self.aggregation_temporality,
                 "is_monotonic": self.is_monotonic,
             }
@@ -71,30 +95,14 @@ class Gauge:
     def to_json(self) -> str:
         return dumps(
             {
-                "data_points": dumps(
-                    [asdict(data_point) for data_point in self.data_points]
-                )
+                "data_points": [
+                    loads(data_point.to_json())
+                    for data_point in self.data_points
+                ],
             }
         )
 
 
-@dataclass(frozen=True)
-class HistogramDataPoint:
-    """Single data point in a timeseries that describes the time-varying scalar
-    value of a metric.
-    """
-
-    attributes: Attributes
-    start_time_unix_nano: int
-    time_unix_nano: int
-    count: int
-    sum: Union[int, float]
-    bucket_counts: Sequence[int]
-    explicit_bounds: Sequence[float]
-    min: float
-    max: float
-
-
 @dataclass(frozen=True)
 class Histogram:
     """Represents the type of a metric that is calculated by aggregating as a
@@ -108,9 +116,10 @@ class Histogram:
     def to_json(self) -> str:
         return dumps(
             {
-                "data_points": dumps(
-                    [asdict(data_point) for data_point in self.data_points]
-                ),
+                "data_points": [
+                    loads(data_point.to_json())
+                    for data_point in self.data_points
+                ],
                 "aggregation_temporality": self.aggregation_temporality,
             }
         )
@@ -126,17 +135,17 @@ class Metric:
     exported."""
 
     name: str
-    description: str
-    unit: str
+    description: Optional[str]
+    unit: Optional[str]
     data: DataT
 
     def to_json(self) -> str:
         return dumps(
             {
                 "name": self.name,
-                "description": self.description if self.description else "",
-                "unit": self.unit if self.unit else "",
-                "data": self.data.to_json(),
+                "description": self.description or "",
+                "unit": self.unit or "",
+                "data": loads(self.data.to_json()),
             }
         )
 
@@ -149,6 +158,21 @@ class ScopeMetrics:
     metrics: Sequence[Metric]
     schema_url: str
 
+    def to_json(self) -> str:
+        return dumps(
+            {
+                "scope": {
+                    "name": self.scope.name,
+                    "version": self.scope.version,
+                    "schema_url": self.scope.schema_url,
+                },
+                "metrics": [
+                    loads(metric.to_json()) for metric in self.metrics
+                ],
+                "schema_url": self.schema_url,
+            }
+        )
+
 
 @dataclass(frozen=True)
 class ResourceMetrics:
@@ -158,9 +182,34 @@ class ResourceMetrics:
     scope_metrics: Sequence[ScopeMetrics]
     schema_url: str
 
+    def to_json(self) -> str:
+        return dumps(
+            {
+                "resource": {
+                    "attributes": dict(self.resource.attributes.items()),
+                    "schema_url": self.resource.schema_url,
+                },
+                "scope_metrics": [
+                    loads(scope_metrics.to_json())
+                    for scope_metrics in self.scope_metrics
+                ],
+                "schema_url": self.schema_url,
+            }
+        )
+
 
 @dataclass(frozen=True)
 class MetricsData:
     """An array of ResourceMetrics"""
 
     resource_metrics: Sequence[ResourceMetrics]
+
+    def to_json(self) -> str:
+        return dumps(
+            {
+                "resource_metrics": [
+                    loads(resource_metrics.to_json())
+                    for resource_metrics in self.resource_metrics
+                ]
+            }
+        )

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

@@ -0,0 +1,37 @@
+# Copyright The OpenTelemetry Authors
+#
+# 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 unittest import TestCase
+
+from opentelemetry import metrics
+from opentelemetry.sdk.metrics import MeterProvider
+from opentelemetry.sdk.metrics.export import (
+    ConsoleMetricExporter,
+    PeriodicExportingMetricReader,
+)
+
+
+class TestConsoleExporter(TestCase):
+    def test_console_exporter(self):
+
+        try:
+            exporter = ConsoleMetricExporter()
+            reader = PeriodicExportingMetricReader(exporter)
+            provider = MeterProvider(metric_readers=[reader])
+            metrics.set_meter_provider(provider)
+            meter = metrics.get_meter(__name__)
+            counter = meter.create_counter("test")
+            counter.add(1)
+        except Exception as error:
+            self.fail(f"Unexpected exception {error} raised")